/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or https://opensource.org/licenses/CDDL-1.0.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2012, 2020 by Delphix. All rights reserved.
* Copyright (c) 2016 Gvozden Nešković. All rights reserved.
*/
#include <sys/zfs_context.h>
#include <sys/spa.h>
#include <sys/spa_impl.h>
#include <sys/zap.h>
#include <sys/vdev_impl.h>
#include <sys/metaslab_impl.h>
#include <sys/zio.h>
#include <sys/zio_checksum.h>
#include <sys/dmu_tx.h>
#include <sys/abd.h>
#include <sys/zfs_rlock.h>
#include <sys/fs/zfs.h>
#include <sys/fm/fs/zfs.h>
#include <sys/vdev_raidz.h>
#include <sys/vdev_raidz_impl.h>
#include <sys/vdev_draid.h>
#include <sys/uberblock_impl.h>
#include <sys/dsl_scan.h>
#ifdef ZFS_DEBUG
#include <sys/vdev.h> /* For vdev_xlate() in vdev_raidz_io_verify() */
#endif
/*
* Virtual device vector for RAID-Z.
*
* This vdev supports single, double, and triple parity. For single parity,
* we use a simple XOR of all the data columns. For double or triple parity,
* we use a special case of Reed-Solomon coding. This extends the
* technique described in "The mathematics of RAID-6" by H. Peter Anvin by
* drawing on the system described in "A Tutorial on Reed-Solomon Coding for
* Fault-Tolerance in RAID-like Systems" by James S. Plank on which the
* former is also based. The latter is designed to provide higher performance
* for writes.
*
* Note that the Plank paper claimed to support arbitrary N+M, but was then
* amended six years later identifying a critical flaw that invalidates its
* claims. Nevertheless, the technique can be adapted to work for up to
* triple parity. For additional parity, the amendment "Note: Correction to
* the 1997 Tutorial on Reed-Solomon Coding" by James S. Plank and Ying Ding
* is viable, but the additional complexity means that write performance will
* suffer.
*
* All of the methods above operate on a Galois field, defined over the
* integers mod 2^N. In our case we choose N=8 for GF(8) so that all elements
* can be expressed with a single byte. Briefly, the operations on the
* field are defined as follows:
*
* o addition (+) is represented by a bitwise XOR
* o subtraction (-) is therefore identical to addition: A + B = A - B
* o multiplication of A by 2 is defined by the following bitwise expression:
*
* (A * 2)_7 = A_6
* (A * 2)_6 = A_5
* (A * 2)_5 = A_4
* (A * 2)_4 = A_3 + A_7
* (A * 2)_3 = A_2 + A_7
* (A * 2)_2 = A_1 + A_7
* (A * 2)_1 = A_0
* (A * 2)_0 = A_7
*
* In C, multiplying by 2 is therefore ((a << 1) ^ ((a & 0x80) ? 0x1d : 0)).
* As an aside, this multiplication is derived from the error correcting
* primitive polynomial x^8 + x^4 + x^3 + x^2 + 1.
*
* Observe that any number in the field (except for 0) can be expressed as a
* power of 2 -- a generator for the field. We store a table of the powers of
* 2 and logs base 2 for quick look ups, and exploit the fact that A * B can
* be rewritten as 2^(log_2(A) + log_2(B)) (where '+' is normal addition rather
* than field addition). The inverse of a field element A (A^-1) is therefore
* A ^ (255 - 1) = A^254.
*
* The up-to-three parity columns, P, Q, R over several data columns,
* D_0, ... D_n-1, can be expressed by field operations:
*
* P = D_0 + D_1 + ... + D_n-2 + D_n-1
* Q = 2^n-1 * D_0 + 2^n-2 * D_1 + ... + 2^1 * D_n-2 + 2^0 * D_n-1
* = ((...((D_0) * 2 + D_1) * 2 + ...) * 2 + D_n-2) * 2 + D_n-1
* R = 4^n-1 * D_0 + 4^n-2 * D_1 + ... + 4^1 * D_n-2 + 4^0 * D_n-1
* = ((...((D_0) * 4 + D_1) * 4 + ...) * 4 + D_n-2) * 4 + D_n-1
*
* We chose 1, 2, and 4 as our generators because 1 corresponds to the trivial
* XOR operation, and 2 and 4 can be computed quickly and generate linearly-
* independent coefficients. (There are no additional coefficients that have
* this property which is why the uncorrected Plank method breaks down.)
*
* See the reconstruction code below for how P, Q and R can used individually
* or in concert to recover missing data columns.
*/
#define VDEV_RAIDZ_P 0
#define VDEV_RAIDZ_Q 1
#define VDEV_RAIDZ_R 2
#define VDEV_RAIDZ_MUL_2(x) (((x) << 1) ^ (((x) & 0x80) ? 0x1d : 0))
#define VDEV_RAIDZ_MUL_4(x) (VDEV_RAIDZ_MUL_2(VDEV_RAIDZ_MUL_2(x)))
/*
* We provide a mechanism to perform the field multiplication operation on a
* 64-bit value all at once rather than a byte at a time. This works by
* creating a mask from the top bit in each byte and using that to
* conditionally apply the XOR of 0x1d.
*/
#define VDEV_RAIDZ_64MUL_2(x, mask) \
{ \
(mask) = (x) & 0x8080808080808080ULL; \
(mask) = ((mask) << 1) - ((mask) >> 7); \
(x) = (((x) << 1) & 0xfefefefefefefefeULL) ^ \
((mask) & 0x1d1d1d1d1d1d1d1dULL); \
}
#define VDEV_RAIDZ_64MUL_4(x, mask) \
{ \
VDEV_RAIDZ_64MUL_2((x), mask); \
VDEV_RAIDZ_64MUL_2((x), mask); \
}
/*
* Big Theory Statement for how a RAIDZ VDEV is expanded
*
* An existing RAIDZ VDEV can be expanded by attaching a new disk. Expansion
* works with all three RAIDZ parity choices, including RAIDZ1, 2, or 3. VDEVs
* that have been previously expanded can be expanded again.
*
* The RAIDZ VDEV must be healthy (must be able to write to all the drives in
* the VDEV) when an expansion starts. And the expansion will pause if any
* disk in the VDEV fails, and resume once the VDEV is healthy again. All other
* operations on the pool can continue while an expansion is in progress (e.g.
* read/write, snapshot, zpool add, etc). Except zpool checkpoint, zpool trim,
* and zpool initialize which can't be run during an expansion. Following a
* reboot or export/import, the expansion resumes where it left off.
*
* == Reflowing the Data ==
*
* The expansion involves reflowing (copying) the data from the current set
* of disks to spread it across the new set which now has one more disk. This
* reflow operation is similar to reflowing text when the column width of a
* text editor window is expanded. The text doesn’t change but the location of
* the text changes to accommodate the new width. An example reflow result for
* a 4-wide RAIDZ1 to a 5-wide is shown below.
*
* Reflow End State
* Each letter indicates a parity group (logical stripe)
*
* Before expansion After Expansion
* D1 D2 D3 D4 D1 D2 D3 D4 D5
* +------+------+------+------+ +------+------+------+------+------+
* | | | | | | | | | | |
* | A | A | A | A | | A | A | A | A | B |
* | 1| 2| 3| 4| | 1| 2| 3| 4| 5|
* +------+------+------+------+ +------+------+------+------+------+
* | | | | | | | | | | |
* | B | B | C | C | | B | C | C | C | C |
* | 5| 6| 7| 8| | 6| 7| 8| 9| 10|
* +------+------+------+------+ +------+------+------+------+------+
* | | | | | | | | | | |
* | C | C | D | D | | D | D | E | E | E |
* | 9| 10| 11| 12| | 11| 12| 13| 14| 15|
* +------+------+------+------+ +------+------+------+------+------+
* | | | | | | | | | | |
* | E | E | E | E | --> | E | F | F | G | G |
* | 13| 14| 15| 16| | 16| 17| 18|p 19| 20|
* +------+------+------+------+ +------+------+------+------+------+
* | | | | | | | | | | |
* | F | F | G | G | | G | G | H | H | H |
* | 17| 18| 19| 20| | 21| 22| 23| 24| 25|
* +------+------+------+------+ +------+------+------+------+------+
* | | | | | | | | | | |
* | G | G | H | H | | H | I | I | J | J |
* | 21| 22| 23| 24| | 26| 27| 28| 29| 30|
* +------+------+------+------+ +------+------+------+------+------+
* | | | | | | | | | | |
* | H | H | I | I | | J | J | | | K |
* | 25| 26| 27| 28| | 31| 32| 33| 34| 35|
* +------+------+------+------+ +------+------+------+------+------+
*
* This reflow approach has several advantages. There is no need to read or
* modify the block pointers or recompute any block checksums. The reflow
* doesn’t need to know where the parity sectors reside. We can read and write
* data sequentially and the copy can occur in a background thread in open
* context. The design also allows for fast discovery of what data to copy.
*
* The VDEV metaslabs are processed, one at a time, to copy the block data to
* have it flow across all the disks. The metaslab is disabled for allocations
* during the copy. As an optimization, we only copy the allocated data which
* can be determined by looking at the metaslab range tree. During the copy we
* must maintain the redundancy guarantees of the RAIDZ VDEV (i.e., we still
* need to be able to survive losing parity count disks). This means we
* cannot overwrite data during the reflow that would be needed if a disk is
* lost.
*
* After the reflow completes, all newly-written blocks will have the new
* layout, i.e., they will have the parity to data ratio implied by the new
* number of disks in the RAIDZ group. Even though the reflow copies all of
* the allocated space (data and parity), it is only rearranged, not changed.
*
* This act of reflowing the data has a few implications about blocks
* that were written before the reflow completes:
*
* - Old blocks will still use the same amount of space (i.e., they will have
* the parity to data ratio implied by the old number of disks in the RAIDZ
* group).
* - Reading old blocks will be slightly slower than before the reflow, for
* two reasons. First, we will have to read from all disks in the RAIDZ
* VDEV, rather than being able to skip the children that contain only
* parity of this block (because the data of a single block is now spread
* out across all the disks). Second, in most cases there will be an extra
* bcopy, needed to rearrange the data back to its original layout in memory.
*
* == Scratch Area ==
*
* As we copy the block data, we can only progress to the point that writes
* will not overlap with blocks whose progress has not yet been recorded on
* disk. Since partially-copied rows are always read from the old location,
* we need to stop one row before the sector-wise overlap, to prevent any
* row-wise overlap. For example, in the diagram above, when we reflow sector
* B6 it will overwite the original location for B5.
*
* To get around this, a scratch space is used so that we can start copying
* without risking data loss by overlapping the row. As an added benefit, it
* improves performance at the beginning of the reflow, but that small perf
* boost wouldn't be worth the complexity on its own.
*
* Ideally we want to copy at least 2 * (new_width)^2 so that we have a
* separation of 2*(new_width+1) and a chunk size of new_width+2. With the max
* RAIDZ width of 255 and 4K sectors this would be 2MB per disk. In practice
* the widths will likely be single digits so we can get a substantial chuck
* size using only a few MB of scratch per disk.
*
* The scratch area is persisted to disk which holds a large amount of reflowed
* state. We can always read the partially written stripes when a disk fails or
* the copy is interrupted (crash) during the initial copying phase and also
* get past a small chunk size restriction. At a minimum, the scratch space
* must be large enough to get us to the point that one row does not overlap
* itself when moved (i.e new_width^2). But going larger is even better. We
* use the 3.5 MiB reserved "boot" space that resides after the ZFS disk labels
* as our scratch space to handle overwriting the initial part of the VDEV.
*
* 0 256K 512K 4M
* +------+------+-----------------------+-----------------------------
* | VDEV | VDEV | Boot Block (3.5M) | Allocatable space ...
* | L0 | L1 | Reserved | (Metaslabs)
* +------+------+-----------------------+-------------------------------
* Scratch Area
*
* == Reflow Progress Updates ==
* After the initial scratch-based reflow, the expansion process works
* similarly to device removal. We create a new open context thread which
* reflows the data, and periodically kicks off sync tasks to update logical
* state. In this case, state is the committed progress (offset of next data
* to copy). We need to persist the completed offset on disk, so that if we
* crash we know which format each VDEV offset is in.
*
* == Time Dependent Geometry ==
*
* In non-expanded RAIDZ, blocks are read from disk in a column by column
* fashion. For a multi-row block, the second sector is in the first column
* not in the second column. This allows us to issue full reads for each
* column directly into the request buffer. The block data is thus laid out
* sequentially in a column-by-column fashion.
*
* For example, in the before expansion diagram above, one logical block might
* be sectors G19-H26. The parity is in G19,H23; and the data is in
* G20,H24,G21,H25,G22,H26.
*
* After a block is reflowed, the sectors that were all in the original column
* data can now reside in different columns. When reading from an expanded
* VDEV, we need to know the logical stripe width for each block so we can
* reconstitute the block’s data after the reads are completed. Likewise,
* when we perform the combinatorial reconstruction we need to know the
* original width so we can retry combinations from the past layouts.
*
* Time dependent geometry is what we call having blocks with different layouts
* (stripe widths) in the same VDEV. This time-dependent geometry uses the
* block’s birth time (+ the time expansion ended) to establish the correct
* width for a given block. After an expansion completes, we record the time
* for blocks written with a particular width (geometry).
*
* == On Disk Format Changes ==
*
* New pool feature flag, 'raidz_expansion' whose reference count is the number
* of RAIDZ VDEVs that have been expanded.
*
* The blocks on expanded RAIDZ VDEV can have different logical stripe widths.
*
* Since the uberblock can point to arbitrary blocks, which might be on the
* expanding RAIDZ, and might or might not have been expanded. We need to know
* which way a block is laid out before reading it. This info is the next
* offset that needs to be reflowed and we persist that in the uberblock, in
* the new ub_raidz_reflow_info field, as opposed to the MOS or the vdev label.
* After the expansion is complete, we then use the raidz_expand_txgs array
* (see below) to determine how to read a block and the ub_raidz_reflow_info
* field no longer required.
*
* The uberblock's ub_raidz_reflow_info field also holds the scratch space
* state (i.e., active or not) which is also required before reading a block
* during the initial phase of reflowing the data.
*
* The top-level RAIDZ VDEV has two new entries in the nvlist:
*
* 'raidz_expand_txgs' array: logical stripe widths by txg are recorded here
* and used after the expansion is complete to
* determine how to read a raidz block
* 'raidz_expanding' boolean: present during reflow and removed after completion
* used during a spa import to resume an unfinished
* expansion
*
* And finally the VDEVs top zap adds the following informational entries:
* VDEV_TOP_ZAP_RAIDZ_EXPAND_STATE
* VDEV_TOP_ZAP_RAIDZ_EXPAND_START_TIME
* VDEV_TOP_ZAP_RAIDZ_EXPAND_END_TIME
* VDEV_TOP_ZAP_RAIDZ_EXPAND_BYTES_COPIED
*/
/*
* For testing only: pause the raidz expansion after reflowing this amount.
* (accessed by ZTS and ztest)
*/
#ifdef _KERNEL
static
#endif /* _KERNEL */
unsigned long raidz_expand_max_reflow_bytes = 0;
/*
* For testing only: pause the raidz expansion at a certain point.
*/
uint_t raidz_expand_pause_point = 0;
/*
* Maximum amount of copy io's outstanding at once.
*/
static unsigned long raidz_expand_max_copy_bytes = 10 * SPA_MAXBLOCKSIZE;
/*
* Apply raidz map abds aggregation if the number of rows in the map is equal
* or greater than the value below.
*/
static unsigned long raidz_io_aggregate_rows = 4;
/*
* Automatically start a pool scrub when a RAIDZ expansion completes in
* order to verify the checksums of all blocks which have been copied
* during the expansion. Automatic scrubbing is enabled by default and
* is strongly recommended.
*/
static int zfs_scrub_after_expand = 1;
static void
vdev_raidz_row_free(raidz_row_t *rr)
{
for (int c = 0; c < rr->rr_cols; c++) {
raidz_col_t *rc = &rr->rr_col[c];
if (rc->rc_size != 0)
abd_free(rc->rc_abd);
if (rc->rc_orig_data != NULL)
abd_free(rc->rc_orig_data);
}
if (rr->rr_abd_empty != NULL)
abd_free(rr->rr_abd_empty);
kmem_free(rr, offsetof(raidz_row_t, rr_col[rr->rr_scols]));
}
void
vdev_raidz_map_free(raidz_map_t *rm)
{
for (int i = 0; i < rm->rm_nrows; i++)
vdev_raidz_row_free(rm->rm_row[i]);
if (rm->rm_nphys_cols) {
for (int i = 0; i < rm->rm_nphys_cols; i++) {
if (rm->rm_phys_col[i].rc_abd != NULL)
abd_free(rm->rm_phys_col[i].rc_abd);
}
kmem_free(rm->rm_phys_col, sizeof (raidz_col_t) *
rm->rm_nphys_cols);
}
ASSERT3P(rm->rm_lr, ==, NULL);
kmem_free(rm, offsetof(raidz_map_t, rm_row[rm->rm_nrows]));
}
static void
vdev_raidz_map_free_vsd(zio_t *zio)
{
raidz_map_t *rm = zio->io_vsd;
vdev_raidz_map_free(rm);
}
static int
vdev_raidz_reflow_compare(const void *x1, const void *x2)
{
const reflow_node_t *l = x1;
const reflow_node_t *r = x2;
return (TREE_CMP(l->re_txg, r->re_txg));
}
const zio_vsd_ops_t vdev_raidz_vsd_ops = {
.vsd_free = vdev_raidz_map_free_vsd,
};
raidz_row_t *
vdev_raidz_row_alloc(int cols)
{
raidz_row_t *rr =
kmem_zalloc(offsetof(raidz_row_t, rr_col[cols]), KM_SLEEP);
rr->rr_cols = cols;
rr->rr_scols = cols;
for (int c = 0; c < cols; c++) {
raidz_col_t *rc = &rr->rr_col[c];
rc->rc_shadow_devidx = INT_MAX;
rc->rc_shadow_offset = UINT64_MAX;
rc->rc_allow_repair = 1;
}
return (rr);
}
static void
vdev_raidz_map_alloc_write(zio_t *zio, raidz_map_t *rm, uint64_t ashift)
{
int c;
int nwrapped = 0;
uint64_t off = 0;
raidz_row_t *rr = rm->rm_row[0];
ASSERT3U(zio->io_type, ==, ZIO_TYPE_WRITE);
ASSERT3U(rm->rm_nrows, ==, 1);
/*
* Pad any parity columns with additional space to account for skip
* sectors.
*/
if (rm->rm_skipstart < rr->rr_firstdatacol) {
ASSERT0(rm->rm_skipstart);
nwrapped = rm->rm_nskip;
} else if (rr->rr_scols < (rm->rm_skipstart + rm->rm_nskip)) {
nwrapped =
(rm->rm_skipstart + rm->rm_nskip) % rr->rr_scols;
}
/*
* Optional single skip sectors (rc_size == 0) will be handled in
* vdev_raidz_io_start_write().
*/
int skipped = rr->rr_scols - rr->rr_cols;
/* Allocate buffers for the parity columns */
for (c = 0; c < rr->rr_firstdatacol; c++) {
raidz_col_t *rc = &rr->rr_col[c];
/*
* Parity columns will pad out a linear ABD to account for
* the skip sector. A linear ABD is used here because
* parity calculations use the ABD buffer directly to calculate
* parity. This avoids doing a memcpy back to the ABD after the
* parity has been calculated. By issuing the parity column
* with the skip sector we can reduce contention on the child
* VDEV queue locks (vq_lock).
*/
if (c < nwrapped) {
rc->rc_abd = abd_alloc_linear(
rc->rc_size + (1ULL << ashift), B_FALSE);
abd_zero_off(rc->rc_abd, rc->rc_size, 1ULL << ashift);
skipped++;
} else {
rc->rc_abd = abd_alloc_linear(rc->rc_size, B_FALSE);
}
}
for (off = 0; c < rr->rr_cols; c++) {
raidz_col_t *rc = &rr->rr_col[c];
abd_t *abd = abd_get_offset_struct(&rc->rc_abdstruct,
zio->io_abd, off, rc->rc_size);
/*
* Generate I/O for skip sectors to improve aggregation
* continuity. We will use gang ABD's to reduce contention
* on the child VDEV queue locks (vq_lock) by issuing
* a single I/O that contains the data and skip sector.
*
* It is important to make sure that rc_size is not updated
* even though we are adding a skip sector to the ABD. When
* calculating the parity in vdev_raidz_generate_parity_row()
* the rc_size is used to iterate through the ABD's. We can
* not have zero'd out skip sectors used for calculating
* parity for raidz, because those same sectors are not used
* during reconstruction.
*/
if (c >= rm->rm_skipstart && skipped < rm->rm_nskip) {
rc->rc_abd = abd_alloc_gang();
abd_gang_add(rc->rc_abd, abd, B_TRUE);
abd_gang_add(rc->rc_abd,
abd_get_zeros(1ULL << ashift), B_TRUE);
skipped++;
} else {
rc->rc_abd = abd;
}
off += rc->rc_size;
}
ASSERT3U(off, ==, zio->io_size);
ASSERT3S(skipped, ==, rm->rm_nskip);
}
static void
vdev_raidz_map_alloc_read(zio_t *zio, raidz_map_t *rm)
{
int c;
raidz_row_t *rr = rm->rm_row[0];
ASSERT3U(rm->rm_nrows, ==, 1);
/* Allocate buffers for the parity columns */
for (c = 0; c < rr->rr_firstdatacol; c++)
rr->rr_col[c].rc_abd =
abd_alloc_linear(rr->rr_col[c].rc_size, B_FALSE);
for (uint64_t off = 0; c < rr->rr_cols; c++) {
raidz_col_t *rc = &rr->rr_col[c];
rc->rc_abd = abd_get_offset_struct(&rc->rc_abdstruct,
zio->io_abd, off, rc->rc_size);
off += rc->rc_size;
}
}
/*
* Divides the IO evenly across all child vdevs; usually, dcols is
* the number of children in the target vdev.
*
* Avoid inlining the function to keep vdev_raidz_io_start(), which
* is this functions only caller, as small as possible on the stack.
*/
noinline raidz_map_t *
vdev_raidz_map_alloc(zio_t *zio, uint64_t ashift, uint64_t dcols,
uint64_t nparity)
{
raidz_row_t *rr;
/* The starting RAIDZ (parent) vdev sector of the block. */
uint64_t b = zio->io_offset >> ashift;
/* The zio's size in units of the vdev's minimum sector size. */
uint64_t s = zio->io_size >> ashift;
/* The first column for this stripe. */
uint64_t f = b % dcols;
/* The starting byte offset on each child vdev. */
uint64_t o = (b / dcols) << ashift;
uint64_t acols, scols;
raidz_map_t *rm =
kmem_zalloc(offsetof(raidz_map_t, rm_row[1]), KM_SLEEP);
rm->rm_nrows = 1;
/*
* "Quotient": The number of data sectors for this stripe on all but
* the "big column" child vdevs that also contain "remainder" data.
*/
uint64_t q = s / (dcols - nparity);
/*
* "Remainder": The number of partial stripe data sectors in this I/O.
* This will add a sector to some, but not all, child vdevs.
*/
uint64_t r = s - q * (dcols - nparity);
/* The number of "big columns" - those which contain remainder data. */
uint64_t bc = (r == 0 ? 0 : r + nparity);
/*
* The total number of data and parity sectors associated with
* this I/O.
*/
uint64_t tot = s + nparity * (q + (r == 0 ? 0 : 1));
/*
* acols: The columns that will be accessed.
* scols: The columns that will be accessed or skipped.
*/
if (q == 0) {
/* Our I/O request doesn't span all child vdevs. */
acols = bc;
scols = MIN(dcols, roundup(bc, nparity + 1));
} else {
acols = dcols;
scols = dcols;
}
ASSERT3U(acols, <=, scols);
rr = vdev_raidz_row_alloc(scols);
rm->rm_row[0] = rr;
rr->rr_cols = acols;
rr->rr_bigcols = bc;
rr->rr_firstdatacol = nparity;
#ifdef ZFS_DEBUG
rr->rr_offset = zio->io_offset;
rr->rr_size = zio->io_size;
#endif
uint64_t asize = 0;
for (uint64_t c = 0; c < scols; c++) {
raidz_col_t *rc = &rr->rr_col[c];
uint64_t col = f + c;
uint64_t coff = o;
if (col >= dcols) {
col -= dcols;
coff += 1ULL << ashift;
}
rc->rc_devidx = col;
rc->rc_offset = coff;
if (c >= acols)
rc->rc_size = 0;
else if (c < bc)
rc->rc_size = (q + 1) << ashift;
else
rc->rc_size = q << ashift;
asize += rc->rc_size;
}
ASSERT3U(asize, ==, tot << ashift);
rm->rm_nskip = roundup(tot, nparity + 1) - tot;
rm->rm_skipstart = bc;
/*
* If all data stored spans all columns, there's a danger that parity
* will always be on the same device and, since parity isn't read
* during normal operation, that device's I/O bandwidth won't be
* used effectively. We therefore switch the parity every 1MB.
*
* ... at least that was, ostensibly, the theory. As a practical
* matter unless we juggle the parity between all devices evenly, we
* won't see any benefit. Further, occasional writes that aren't a
* multiple of the LCM of the number of children and the minimum
* stripe width are sufficient to avoid pessimal behavior.
* Unfortunately, this decision created an implicit on-disk format
* requirement that we need to support for all eternity, but only
* for single-parity RAID-Z.
*
* If we intend to skip a sector in the zeroth column for padding
* we must make sure to note this swap. We will never intend to
* skip the first column since at least one data and one parity
* column must appear in each row.
*/
ASSERT(rr->rr_cols >= 2);
ASSERT(rr->rr_col[0].rc_size == rr->rr_col[1].rc_size);
if (rr->rr_firstdatacol == 1 && (zio->io_offset & (1ULL << 20))) {
uint64_t devidx = rr->rr_col[0].rc_devidx;
o = rr->rr_col[0].rc_offset;
rr->rr_col[0].rc_devidx = rr->rr_col[1].rc_devidx;
rr->rr_col[0].rc_offset = rr->rr_col[1].rc_offset;
rr->rr_col[1].rc_devidx = devidx;
rr->rr_col[1].rc_offset = o;
if (rm->rm_skipstart == 0)
rm->rm_skipstart = 1;
}
if (zio->io_type == ZIO_TYPE_WRITE) {
vdev_raidz_map_alloc_write(zio, rm, ashift);
} else {
vdev_raidz_map_alloc_read(zio, rm);
}
/* init RAIDZ parity ops */
rm->rm_ops = vdev_raidz_math_get_ops();
return (rm);
}
/*
* Everything before reflow_offset_synced should have been moved to the new
* location (read and write completed). However, this may not yet be reflected
* in the on-disk format (e.g. raidz_reflow_sync() has been called but the
* uberblock has not yet been written). If reflow is not in progress,
* reflow_offset_synced should be UINT64_MAX. For each row, if the row is
* entirely before reflow_offset_synced, it will come from the new location.
* Otherwise this row will come from the old location. Therefore, rows that
* straddle the reflow_offset_synced will come from the old location.
*
* For writes, reflow_offset_next is the next offset to copy. If a sector has
* been copied, but not yet reflected in the on-disk progress
* (reflow_offset_synced), it will also be written to the new (already copied)
* offset.
*/
noinline raidz_map_t *
vdev_raidz_map_alloc_expanded(zio_t *zio,
uint64_t ashift, uint64_t physical_cols, uint64_t logical_cols,
uint64_t nparity, uint64_t reflow_offset_synced,
uint64_t reflow_offset_next, boolean_t use_scratch)
{
abd_t *abd = zio->io_abd;
uint64_t offset = zio->io_offset;
uint64_t size = zio->io_size;
/* The zio's size in units of the vdev's minimum sector size. */
uint64_t s = size >> ashift;
/*
* "Quotient": The number of data sectors for this stripe on all but
* the "big column" child vdevs that also contain "remainder" data.
* AKA "full rows"
*/
uint64_t q = s / (logical_cols - nparity);
/*
* "Remainder": The number of partial stripe data sectors in this I/O.
* This will add a sector to some, but not all, child vdevs.
*/
uint64_t r = s - q * (logical_cols - nparity);
/* The number of "big columns" - those which contain remainder data. */
uint64_t bc = (r == 0 ? 0 : r + nparity);
/*
* The total number of data and parity sectors associated with
* this I/O.
*/
uint64_t tot = s + nparity * (q + (r == 0 ? 0 : 1));
/* How many rows contain data (not skip) */
uint64_t rows = howmany(tot, logical_cols);
int cols = MIN(tot, logical_cols);
raidz_map_t *rm =
kmem_zalloc(offsetof(raidz_map_t, rm_row[rows]),
KM_SLEEP);
rm->rm_nrows = rows;
rm->rm_nskip = roundup(tot, nparity + 1) - tot;
rm->rm_skipstart = bc;
uint64_t asize = 0;
for (uint64_t row = 0; row < rows; row++) {
boolean_t row_use_scratch = B_FALSE;
raidz_row_t *rr = vdev_raidz_row_alloc(cols);
rm->rm_row[row] = rr;
/* The starting RAIDZ (parent) vdev sector of the row. */
uint64_t b = (offset >> ashift) + row * logical_cols;
/*
* If we are in the middle of a reflow, and the copying has
* not yet completed for any part of this row, then use the
* old location of this row. Note that reflow_offset_synced
* reflects the i/o that's been completed, because it's
* updated by a synctask, after zio_wait(spa_txg_zio[]).
* This is sufficient for our check, even if that progress
* has not yet been recorded to disk (reflected in
* spa_ubsync). Also note that we consider the last row to
* be "full width" (`cols`-wide rather than `bc`-wide) for
* this calculation. This causes a tiny bit of unnecessary
* double-writes but is safe and simpler to calculate.
*/
int row_phys_cols = physical_cols;
if (b + cols > reflow_offset_synced >> ashift)
row_phys_cols--;
else if (use_scratch)
row_use_scratch = B_TRUE;
/* starting child of this row */
uint64_t child_id = b % row_phys_cols;
/* The starting byte offset on each child vdev. */
uint64_t child_offset = (b / row_phys_cols) << ashift;
/*
* Note, rr_cols is the entire width of the block, even
* if this row is shorter. This is needed because parity
* generation (for Q and R) needs to know the entire width,
* because it treats the short row as though it was
* full-width (and the "phantom" sectors were zero-filled).
*
* Another approach to this would be to set cols shorter
* (to just the number of columns that we might do i/o to)
* and have another mechanism to tell the parity generation
* about the "entire width". Reconstruction (at least
* vdev_raidz_reconstruct_general()) would also need to
* know about the "entire width".
*/
rr->rr_firstdatacol = nparity;
#ifdef ZFS_DEBUG
/*
* note: rr_size is PSIZE, not ASIZE
*/
rr->rr_offset = b << ashift;
rr->rr_size = (rr->rr_cols - rr->rr_firstdatacol) << ashift;
#endif
for (int c = 0; c < rr->rr_cols; c++, child_id++) {
if (child_id >= row_phys_cols) {
child_id -= row_phys_cols;
child_offset += 1ULL << ashift;
}
raidz_col_t *rc = &rr->rr_col[c];
rc->rc_devidx = child_id;
rc->rc_offset = child_offset;
/*
* Get this from the scratch space if appropriate.
* This only happens if we crashed in the middle of
* raidz_reflow_scratch_sync() (while it's running,
* the rangelock prevents us from doing concurrent
* io), and even then only during zpool import or
* when the pool is imported readonly.
*/
if (row_use_scratch)
rc->rc_offset -= VDEV_BOOT_SIZE;
uint64_t dc = c - rr->rr_firstdatacol;
if (c < rr->rr_firstdatacol) {
rc->rc_size = 1ULL << ashift;
/*
* Parity sectors' rc_abd's are set below
* after determining if this is an aggregation.
*/
} else if (row == rows - 1 && bc != 0 && c >= bc) {
/*
* Past the end of the block (even including
* skip sectors). This sector is part of the
* map so that we have full rows for p/q parity
* generation.
*/
rc->rc_size = 0;
rc->rc_abd = NULL;
} else {
/* "data column" (col excluding parity) */
uint64_t off;
if (c < bc || r == 0) {
off = dc * rows + row;
} else {
off = r * rows +
(dc - r) * (rows - 1) + row;
}
rc->rc_size = 1ULL << ashift;
rc->rc_abd = abd_get_offset_struct(
&rc->rc_abdstruct, abd, off << ashift,
rc->rc_size);
}
if (rc->rc_size == 0)
continue;
/*
* If any part of this row is in both old and new
* locations, the primary location is the old
* location. If this sector was already copied to the
* new location, we need to also write to the new,
* "shadow" location.
*
* Note, `row_phys_cols != physical_cols` indicates
* that the primary location is the old location.
* `b+c < reflow_offset_next` indicates that the copy
* to the new location has been initiated. We know
* that the copy has completed because we have the
* rangelock, which is held exclusively while the
* copy is in progress.
*/
if (row_use_scratch ||
(row_phys_cols != physical_cols &&
b + c < reflow_offset_next >> ashift)) {
rc->rc_shadow_devidx = (b + c) % physical_cols;
rc->rc_shadow_offset =
((b + c) / physical_cols) << ashift;
if (row_use_scratch)
rc->rc_shadow_offset -= VDEV_BOOT_SIZE;
}
asize += rc->rc_size;
}
/*
* See comment in vdev_raidz_map_alloc()
*/
if (rr->rr_firstdatacol == 1 && rr->rr_cols > 1 &&
(offset & (1ULL << 20))) {
ASSERT(rr->rr_cols >= 2);
ASSERT(rr->rr_col[0].rc_size == rr->rr_col[1].rc_size);
int devidx0 = rr->rr_col[0].rc_devidx;
uint64_t offset0 = rr->rr_col[0].rc_offset;
int shadow_devidx0 = rr->rr_col[0].rc_shadow_devidx;
uint64_t shadow_offset0 =
rr->rr_col[0].rc_shadow_offset;
rr->rr_col[0].rc_devidx = rr->rr_col[1].rc_devidx;
rr->rr_col[0].rc_offset = rr->rr_col[1].rc_offset;
rr->rr_col[0].rc_shadow_devidx =
rr->rr_col[1].rc_shadow_devidx;
rr->rr_col[0].rc_shadow_offset =
rr->rr_col[1].rc_shadow_offset;
rr->rr_col[1].rc_devidx = devidx0;
rr->rr_col[1].rc_offset = offset0;
rr->rr_col[1].rc_shadow_devidx = shadow_devidx0;
rr->rr_col[1].rc_shadow_offset = shadow_offset0;
}
}
ASSERT3U(asize, ==, tot << ashift);
/*
* Determine if the block is contiguous, in which case we can use
* an aggregation.
*/
if (rows >= raidz_io_aggregate_rows) {
rm->rm_nphys_cols = physical_cols;
rm->rm_phys_col =
kmem_zalloc(sizeof (raidz_col_t) * rm->rm_nphys_cols,
KM_SLEEP);
/*
* Determine the aggregate io's offset and size, and check
* that the io is contiguous.
*/
for (int i = 0;
i < rm->rm_nrows && rm->rm_phys_col != NULL; i++) {
raidz_row_t *rr = rm->rm_row[i];
for (int c = 0; c < rr->rr_cols; c++) {
raidz_col_t *rc = &rr->rr_col[c];
raidz_col_t *prc =
&rm->rm_phys_col[rc->rc_devidx];
if (rc->rc_size == 0)
continue;
if (prc->rc_size == 0) {
ASSERT0(prc->rc_offset);
prc->rc_offset = rc->rc_offset;
} else if (prc->rc_offset + prc->rc_size !=
rc->rc_offset) {
/*
* This block is not contiguous and
* therefore can't be aggregated.
* This is expected to be rare, so
* the cost of allocating and then
* freeing rm_phys_col is not
* significant.
*/
kmem_free(rm->rm_phys_col,
sizeof (raidz_col_t) *
rm->rm_nphys_cols);
rm->rm_phys_col = NULL;
rm->rm_nphys_cols = 0;
break;
}
prc->rc_size += rc->rc_size;
}
}
}
if (rm->rm_phys_col != NULL) {
/*
* Allocate aggregate ABD's.
*/
for (int i = 0; i < rm->rm_nphys_cols; i++) {
raidz_col_t *prc = &rm->rm_phys_col[i];
prc->rc_devidx = i;
if (prc->rc_size == 0)
continue;
prc->rc_abd =
abd_alloc_linear(rm->rm_phys_col[i].rc_size,
B_FALSE);
}
/*
* Point the parity abd's into the aggregate abd's.
*/
for (int i = 0; i < rm->rm_nrows; i++) {
raidz_row_t *rr = rm->rm_row[i];
for (int c = 0; c < rr->rr_firstdatacol; c++) {
raidz_col_t *rc = &rr->rr_col[c];
raidz_col_t *prc =
&rm->rm_phys_col[rc->rc_devidx];
rc->rc_abd =
abd_get_offset_struct(&rc->rc_abdstruct,
prc->rc_abd,
rc->rc_offset - prc->rc_offset,
rc->rc_size);
}
}
} else {
/*
* Allocate new abd's for the parity sectors.
*/
for (int i = 0; i < rm->rm_nrows; i++) {
raidz_row_t *rr = rm->rm_row[i];
for (int c = 0; c < rr->rr_firstdatacol; c++) {
raidz_col_t *rc = &rr->rr_col[c];
rc->rc_abd =
abd_alloc_linear(rc->rc_size,
B_TRUE);
}
}
}
/* init RAIDZ parity ops */
rm->rm_ops = vdev_raidz_math_get_ops();
return (rm);
}
struct pqr_struct {
uint64_t *p;
uint64_t *q;
uint64_t *r;
};
static int
vdev_raidz_p_func(void *buf, size_t size, void *private)
{
struct pqr_struct *pqr = private;
const uint64_t *src = buf;
int cnt = size / sizeof (src[0]);
ASSERT(pqr->p && !pqr->q && !pqr->r);
for (int i = 0; i < cnt; i++, src++, pqr->p++)
*pqr->p ^= *src;
return (0);
}
static int
vdev_raidz_pq_func(void *buf, size_t size, void *private)
{
struct pqr_struct *pqr = private;
const uint64_t *src = buf;
uint64_t mask;
int cnt = size / sizeof (src[0]);
ASSERT(pqr->p && pqr->q && !pqr->r);
for (int i = 0; i < cnt; i++, src++, pqr->p++, pqr->q++) {
*pqr->p ^= *src;
VDEV_RAIDZ_64MUL_2(*pqr->q, mask);
*pqr->q ^= *src;
}
return (0);
}
static int
vdev_raidz_pqr_func(void *buf, size_t size, void *private)
{
struct pqr_struct *pqr = private;
const uint64_t *src = buf;
uint64_t mask;
int cnt = size / sizeof (src[0]);
ASSERT(pqr->p && pqr->q && pqr->r);
for (int i = 0; i < cnt; i++, src++, pqr->p++, pqr->q++, pqr->r++) {
*pqr->p ^= *src;
VDEV_RAIDZ_64MUL_2(*pqr->q, mask);
*pqr->q ^= *src;
VDEV_RAIDZ_64MUL_4(*pqr->r, mask);
*pqr->r ^= *src;
}
return (0);
}
static void
vdev_raidz_generate_parity_p(raidz_row_t *rr)
{
uint64_t *p = abd_to_buf(rr->rr_col[VDEV_RAIDZ_P].rc_abd);
for (int c = rr->rr_firstdatacol; c < rr->rr_cols; c++) {
abd_t *src = rr->rr_col[c].rc_abd;
if (c == rr->rr_firstdatacol) {
abd_copy_to_buf(p, src, rr->rr_col[c].rc_size);
} else {
struct pqr_struct pqr = { p, NULL, NULL };
(void) abd_iterate_func(src, 0, rr->rr_col[c].rc_size,
vdev_raidz_p_func, &pqr);
}
}
}
static void
vdev_raidz_generate_parity_pq(raidz_row_t *rr)
{
uint64_t *p = abd_to_buf(rr->rr_col[VDEV_RAIDZ_P].rc_abd);
uint64_t *q = abd_to_buf(rr->rr_col[VDEV_RAIDZ_Q].rc_abd);
uint64_t pcnt = rr->rr_col[VDEV_RAIDZ_P].rc_size / sizeof (p[0]);
ASSERT(rr->rr_col[VDEV_RAIDZ_P].rc_size ==
rr->rr_col[VDEV_RAIDZ_Q].rc_size);
for (int c = rr->rr_firstdatacol; c < rr->rr_cols; c++) {
abd_t *src = rr->rr_col[c].rc_abd;
uint64_t ccnt = rr->rr_col[c].rc_size / sizeof (p[0]);
if (c == rr->rr_firstdatacol) {
ASSERT(ccnt == pcnt || ccnt == 0);
abd_copy_to_buf(p, src, rr->rr_col[c].rc_size);
(void) memcpy(q, p, rr->rr_col[c].rc_size);
for (uint64_t i = ccnt; i < pcnt; i++) {
p[i] = 0;
q[i] = 0;
}
} else {
struct pqr_struct pqr = { p, q, NULL };
ASSERT(ccnt <= pcnt);
(void) abd_iterate_func(src, 0, rr->rr_col[c].rc_size,
vdev_raidz_pq_func, &pqr);
/*
* Treat short columns as though they are full of 0s.
* Note that there's therefore nothing needed for P.
*/
uint64_t mask;
for (uint64_t i = ccnt; i < pcnt; i++) {
VDEV_RAIDZ_64MUL_2(q[i], mask);
}
}
}
}
static void
vdev_raidz_generate_parity_pqr(raidz_row_t *rr)
{
uint64_t *p = abd_to_buf(rr->rr_col[VDEV_RAIDZ_P].rc_abd);
uint64_t *q = abd_to_buf(rr->rr_col[VDEV_RAIDZ_Q].rc_abd);
uint64_t *r = abd_to_buf(rr->rr_col[VDEV_RAIDZ_R].rc_abd);
uint64_t pcnt = rr->rr_col[VDEV_RAIDZ_P].rc_size / sizeof (p[0]);
ASSERT(rr->rr_col[VDEV_RAIDZ_P].rc_size ==
rr->rr_col[VDEV_RAIDZ_Q].rc_size);
ASSERT(rr->rr_col[VDEV_RAIDZ_P].rc_size ==
rr->rr_col[VDEV_RAIDZ_R].rc_size);
for (int c = rr->rr_firstdatacol; c < rr->rr_cols; c++) {
abd_t *src = rr->rr_col[c].rc_abd;
uint64_t ccnt = rr->rr_col[c].rc_size / sizeof (p[0]);
if (c == rr->rr_firstdatacol) {
ASSERT(ccnt == pcnt || ccnt == 0);
abd_copy_to_buf(p, src, rr->rr_col[c].rc_size);
(void) memcpy(q, p, rr->rr_col[c].rc_size);
(void) memcpy(r, p, rr->rr_col[c].rc_size);
for (uint64_t i = ccnt; i < pcnt; i++) {
p[i] = 0;
q[i] = 0;
r[i] = 0;
}
} else {
struct pqr_struct pqr = { p, q, r };
ASSERT(ccnt <= pcnt);
(void) abd_iterate_func(src, 0, rr->rr_col[c].rc_size,
vdev_raidz_pqr_func, &pqr);
/*
* Treat short columns as though they are full of 0s.
* Note that there's therefore nothing needed for P.
*/
uint64_t mask;
for (uint64_t i = ccnt; i < pcnt; i++) {
VDEV_RAIDZ_64MUL_2(q[i], mask);
VDEV_RAIDZ_64MUL_4(r[i], mask);
}
}
}
}
/*
* Generate RAID parity in the first virtual columns according to the number of
* parity columns available.
*/
void
vdev_raidz_generate_parity_row(raidz_map_t *rm, raidz_row_t *rr)
{
if (rr->rr_cols == 0) {
/*
* We are handling this block one row at a time (because
* this block has a different logical vs physical width,
* due to RAIDZ expansion), and this is a pad-only row,
* which has no parity.
*/
return;
}
/* Generate using the new math implementation */
if (vdev_raidz_math_generate(rm, rr) != RAIDZ_ORIGINAL_IMPL)
return;
switch (rr->rr_firstdatacol) {
case 1:
vdev_raidz_generate_parity_p(rr);
break;
case 2:
vdev_raidz_generate_parity_pq(rr);
break;
case 3:
vdev_raidz_generate_parity_pqr(rr);
break;
default:
cmn_err(CE_PANIC, "invalid RAID-Z configuration");
}
}
void
vdev_raidz_generate_parity(raidz_map_t *rm)
{
for (int i = 0; i < rm->rm_nrows; i++) {
raidz_row_t *rr = rm->rm_row[i];
vdev_raidz_generate_parity_row(rm, rr);
}
}
static int
vdev_raidz_reconst_p_func(void *dbuf, void *sbuf, size_t size, void *private)
{
(void) private;
uint64_t *dst = dbuf;
uint64_t *src = sbuf;
int cnt = size / sizeof (src[0]);
for (int i = 0; i < cnt; i++) {
dst[i] ^= src[i];
}
return (0);
}
static int
vdev_raidz_reconst_q_pre_func(void *dbuf, void *sbuf, size_t size,
void *private)
{
(void) private;
uint64_t *dst = dbuf;
uint64_t *src = sbuf;
uint64_t mask;
int cnt = size / sizeof (dst[0]);
for (int i = 0; i < cnt; i++, dst++, src++) {
VDEV_RAIDZ_64MUL_2(*dst, mask);
*dst ^= *src;
}
return (0);
}
static int
vdev_raidz_reconst_q_pre_tail_func(void *buf, size_t size, void *private)
{
(void) private;
uint64_t *dst = buf;
uint64_t mask;
int cnt = size / sizeof (dst[0]);
for (int i = 0; i < cnt; i++, dst++) {
/* same operation as vdev_raidz_reconst_q_pre_func() on dst */
VDEV_RAIDZ_64MUL_2(*dst, mask);
}
return (0);
}
struct reconst_q_struct {
uint64_t *q;
int exp;
};
static int
vdev_raidz_reconst_q_post_func(void *buf, size_t size, void *private)
{
struct reconst_q_struct *rq = private;
uint64_t *dst = buf;
int cnt = size / sizeof (dst[0]);
for (int i = 0; i < cnt; i++, dst++, rq->q++) {
int j;
uint8_t *b;
*dst ^= *rq->q;
for (j = 0, b = (uint8_t *)dst; j < 8; j++, b++) {
*b = vdev_raidz_exp2(*b, rq->exp);
}
}
return (0);
}
struct reconst_pq_struct {
uint8_t *p;
uint8_t *q;
uint8_t *pxy;
uint8_t *qxy;
int aexp;
int bexp;
};
static int
vdev_raidz_reconst_pq_func(void *xbuf, void *ybuf, size_t size, void *private)
{
struct reconst_pq_struct *rpq = private;
uint8_t *xd = xbuf;
uint8_t *yd = ybuf;
for (int i = 0; i < size;
i++, rpq->p++, rpq->q++, rpq->pxy++, rpq->qxy++, xd++, yd++) {
*xd = vdev_raidz_exp2(*rpq->p ^ *rpq->pxy, rpq->aexp) ^
vdev_raidz_exp2(*rpq->q ^ *rpq->qxy, rpq->bexp);
*yd = *rpq->p ^ *rpq->pxy ^ *xd;
}
return (0);
}
static int
vdev_raidz_reconst_pq_tail_func(void *xbuf, size_t size, void *private)
{
struct reconst_pq_struct *rpq = private;
uint8_t *xd = xbuf;
for (int i = 0; i < size;
i++, rpq->p++, rpq->q++, rpq->pxy++, rpq->qxy++, xd++) {
/* same operation as vdev_raidz_reconst_pq_func() on xd */
*xd = vdev_raidz_exp2(*rpq->p ^ *rpq->pxy, rpq->aexp) ^
vdev_raidz_exp2(*rpq->q ^ *rpq->qxy, rpq->bexp);
}
return (0);
}
static void
vdev_raidz_reconstruct_p(raidz_row_t *rr, int *tgts, int ntgts)
{
int x = tgts[0];
abd_t *dst, *src;
if (zfs_flags & ZFS_DEBUG_RAIDZ_RECONSTRUCT)
zfs_dbgmsg("reconstruct_p(rm=%px x=%u)", rr, x);
ASSERT3U(ntgts, ==, 1);
ASSERT3U(x, >=, rr->rr_firstdatacol);
ASSERT3U(x, <, rr->rr_cols);
ASSERT3U(rr->rr_col[x].rc_size, <=, rr->rr_col[VDEV_RAIDZ_P].rc_size);
src = rr->rr_col[VDEV_RAIDZ_P].rc_abd;
dst = rr->rr_col[x].rc_abd;
abd_copy_from_buf(dst, abd_to_buf(src), rr->rr_col[x].rc_size);
for (int c = rr->rr_firstdatacol; c < rr->rr_cols; c++) {
uint64_t size = MIN(rr->rr_col[x].rc_size,
rr->rr_col[c].rc_size);
src = rr->rr_col[c].rc_abd;
if (c == x)
continue;
(void) abd_iterate_func2(dst, src, 0, 0, size,
vdev_raidz_reconst_p_func, NULL);
}
}
static void
vdev_raidz_reconstruct_q(raidz_row_t *rr, int *tgts, int ntgts)
{
int x = tgts[0];
int c, exp;
abd_t *dst, *src;
if (zfs_flags & ZFS_DEBUG_RAIDZ_RECONSTRUCT)
zfs_dbgmsg("reconstruct_q(rm=%px x=%u)", rr, x);
ASSERT(ntgts == 1);
ASSERT(rr->rr_col[x].rc_size <= rr->rr_col[VDEV_RAIDZ_Q].rc_size);
for (c = rr->rr_firstdatacol; c < rr->rr_cols; c++) {
uint64_t size = (c == x) ? 0 : MIN(rr->rr_col[x].rc_size,
rr->rr_col[c].rc_size);
src = rr->rr_col[c].rc_abd;
dst = rr->rr_col[x].rc_abd;
if (c == rr->rr_firstdatacol) {
abd_copy(dst, src, size);
if (rr->rr_col[x].rc_size > size) {
abd_zero_off(dst, size,
rr->rr_col[x].rc_size - size);
}
} else {
ASSERT3U(size, <=, rr->rr_col[x].rc_size);
(void) abd_iterate_func2(dst, src, 0, 0, size,
vdev_raidz_reconst_q_pre_func, NULL);
(void) abd_iterate_func(dst,
size, rr->rr_col[x].rc_size - size,
vdev_raidz_reconst_q_pre_tail_func, NULL);
}
}
src = rr->rr_col[VDEV_RAIDZ_Q].rc_abd;
dst = rr->rr_col[x].rc_abd;
exp = 255 - (rr->rr_cols - 1 - x);
struct reconst_q_struct rq = { abd_to_buf(src), exp };
(void) abd_iterate_func(dst, 0, rr->rr_col[x].rc_size,
vdev_raidz_reconst_q_post_func, &rq);
}
static void
vdev_raidz_reconstruct_pq(raidz_row_t *rr, int *tgts, int ntgts)
{
uint8_t *p, *q, *pxy, *qxy, tmp, a, b, aexp, bexp;
abd_t *pdata, *qdata;
uint64_t xsize, ysize;
int x = tgts[0];
int y = tgts[1];
abd_t *xd, *yd;
if (zfs_flags & ZFS_DEBUG_RAIDZ_RECONSTRUCT)
zfs_dbgmsg("reconstruct_pq(rm=%px x=%u y=%u)", rr, x, y);
ASSERT(ntgts == 2);
ASSERT(x < y);
ASSERT(x >= rr->rr_firstdatacol);
ASSERT(y < rr->rr_cols);
ASSERT(rr->rr_col[x].rc_size >= rr->rr_col[y].rc_size);
/*
* Move the parity data aside -- we're going to compute parity as
* though columns x and y were full of zeros -- Pxy and Qxy. We want to
* reuse the parity generation mechanism without trashing the actual
* parity so we make those columns appear to be full of zeros by
* setting their lengths to zero.
*/
pdata = rr->rr_col[VDEV_RAIDZ_P].rc_abd;
qdata = rr->rr_col[VDEV_RAIDZ_Q].rc_abd;
xsize = rr->rr_col[x].rc_size;
ysize = rr->rr_col[y].rc_size;
rr->rr_col[VDEV_RAIDZ_P].rc_abd =
abd_alloc_linear(rr->rr_col[VDEV_RAIDZ_P].rc_size, B_TRUE);
rr->rr_col[VDEV_RAIDZ_Q].rc_abd =
abd_alloc_linear(rr->rr_col[VDEV_RAIDZ_Q].rc_size, B_TRUE);
rr->rr_col[x].rc_size = 0;
rr->rr_col[y].rc_size = 0;
vdev_raidz_generate_parity_pq(rr);
rr->rr_col[x].rc_size = xsize;
rr->rr_col[y].rc_size = ysize;
p = abd_to_buf(pdata);
q = abd_to_buf(qdata);
pxy = abd_to_buf(rr->rr_col[VDEV_RAIDZ_P].rc_abd);
qxy = abd_to_buf(rr->rr_col[VDEV_RAIDZ_Q].rc_abd);
xd = rr->rr_col[x].rc_abd;
yd = rr->rr_col[y].rc_abd;
/*
* We now have:
* Pxy = P + D_x + D_y
* Qxy = Q + 2^(ndevs - 1 - x) * D_x + 2^(ndevs - 1 - y) * D_y
*
* We can then solve for D_x:
* D_x = A * (P + Pxy) + B * (Q + Qxy)
* where
* A = 2^(x - y) * (2^(x - y) + 1)^-1
* B = 2^(ndevs - 1 - x) * (2^(x - y) + 1)^-1
*
* With D_x in hand, we can easily solve for D_y:
* D_y = P + Pxy + D_x
*/
a = vdev_raidz_pow2[255 + x - y];
b = vdev_raidz_pow2[255 - (rr->rr_cols - 1 - x)];
tmp = 255 - vdev_raidz_log2[a ^ 1];
aexp = vdev_raidz_log2[vdev_raidz_exp2(a, tmp)];
bexp = vdev_raidz_log2[vdev_raidz_exp2(b, tmp)];
ASSERT3U(xsize, >=, ysize);
struct reconst_pq_struct rpq = { p, q, pxy, qxy, aexp, bexp };
(void) abd_iterate_func2(xd, yd, 0, 0, ysize,
vdev_raidz_reconst_pq_func, &rpq);
(void) abd_iterate_func(xd, ysize, xsize - ysize,
vdev_raidz_reconst_pq_tail_func, &rpq);
abd_free(rr->rr_col[VDEV_RAIDZ_P].rc_abd);
abd_free(rr->rr_col[VDEV_RAIDZ_Q].rc_abd);
/*
* Restore the saved parity data.
*/
rr->rr_col[VDEV_RAIDZ_P].rc_abd = pdata;
rr->rr_col[VDEV_RAIDZ_Q].rc_abd = qdata;
}
/*
* In the general case of reconstruction, we must solve the system of linear
* equations defined by the coefficients used to generate parity as well as
* the contents of the data and parity disks. This can be expressed with
* vectors for the original data (D) and the actual data (d) and parity (p)
* and a matrix composed of the identity matrix (I) and a dispersal matrix (V):
*
* __ __ __ __
* | | __ __ | p_0 |
* | V | | D_0 | | p_m-1 |
* | | x | : | = | d_0 |
* | I | | D_n-1 | | : |
* | | ~~ ~~ | d_n-1 |
* ~~ ~~ ~~ ~~
*
* I is simply a square identity matrix of size n, and V is a vandermonde
* matrix defined by the coefficients we chose for the various parity columns
* (1, 2, 4). Note that these values were chosen both for simplicity, speedy
* computation as well as linear separability.
*
* __ __ __ __
* | 1 .. 1 1 1 | | p_0 |
* | 2^n-1 .. 4 2 1 | __ __ | : |
* | 4^n-1 .. 16 4 1 | | D_0 | | p_m-1 |
* | 1 .. 0 0 0 | | D_1 | | d_0 |
* | 0 .. 0 0 0 | x | D_2 | = | d_1 |
* | : : : : | | : | | d_2 |
* | 0 .. 1 0 0 | | D_n-1 | | : |
* | 0 .. 0 1 0 | ~~ ~~ | : |
* | 0 .. 0 0 1 | | d_n-1 |
* ~~ ~~ ~~ ~~
*
* Note that I, V, d, and p are known. To compute D, we must invert the
* matrix and use the known data and parity values to reconstruct the unknown
* data values. We begin by removing the rows in V|I and d|p that correspond
* to failed or missing columns; we then make V|I square (n x n) and d|p
* sized n by removing rows corresponding to unused parity from the bottom up
* to generate (V|I)' and (d|p)'. We can then generate the inverse of (V|I)'
* using Gauss-Jordan elimination. In the example below we use m=3 parity
* columns, n=8 data columns, with errors in d_1, d_2, and p_1:
* __ __
* | 1 1 1 1 1 1 1 1 |
* | 128 64 32 16 8 4 2 1 | <-----+-+-- missing disks
* | 19 205 116 29 64 16 4 1 | / /
* | 1 0 0 0 0 0 0 0 | / /
* | 0 1 0 0 0 0 0 0 | <--' /
* (V|I) = | 0 0 1 0 0 0 0 0 | <---'
* | 0 0 0 1 0 0 0 0 |
* | 0 0 0 0 1 0 0 0 |
* | 0 0 0 0 0 1 0 0 |
* | 0 0 0 0 0 0 1 0 |
* | 0 0 0 0 0 0 0 1 |
* ~~ ~~
* __ __
* | 1 1 1 1 1 1 1 1 |
* | 128 64 32 16 8 4 2 1 |
* | 19 205 116 29 64 16 4 1 |
* | 1 0 0 0 0 0 0 0 |
* | 0 1 0 0 0 0 0 0 |
* (V|I)' = | 0 0 1 0 0 0 0 0 |
* | 0 0 0 1 0 0 0 0 |
* | 0 0 0 0 1 0 0 0 |
* | 0 0 0 0 0 1 0 0 |
* | 0 0 0 0 0 0 1 0 |
* | 0 0 0 0 0 0 0 1 |
* ~~ ~~
*
* Here we employ Gauss-Jordan elimination to find the inverse of (V|I)'. We
* have carefully chosen the seed values 1, 2, and 4 to ensure that this
* matrix is not singular.
* __ __
* | 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 |
* | 19 205 116 29 64 16 4 1 0 1 0 0 0 0 0 0 |
* | 1 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 |
* | 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 0 |
* | 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 |
* | 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 |
* | 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 |
* | 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 |
* ~~ ~~
* __ __
* | 1 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 |
* | 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 |
* | 19 205 116 29 64 16 4 1 0 1 0 0 0 0 0 0 |
* | 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 0 |
* | 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 |
* | 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 |
* | 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 |
* | 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 |
* ~~ ~~
* __ __
* | 1 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 |
* | 0 1 1 0 0 0 0 0 1 0 1 1 1 1 1 1 |
* | 0 205 116 0 0 0 0 0 0 1 19 29 64 16 4 1 |
* | 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 0 |
* | 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 |
* | 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 |
* | 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 |
* | 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 |
* ~~ ~~
* __ __
* | 1 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 |
* | 0 1 1 0 0 0 0 0 1 0 1 1 1 1 1 1 |
* | 0 0 185 0 0 0 0 0 205 1 222 208 141 221 201 204 |
* | 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 0 |
* | 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 |
* | 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 |
* | 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 |
* | 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 |
* ~~ ~~
* __ __
* | 1 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 |
* | 0 1 1 0 0 0 0 0 1 0 1 1 1 1 1 1 |
* | 0 0 1 0 0 0 0 0 166 100 4 40 158 168 216 209 |
* | 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 0 |
* | 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 |
* | 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 |
* | 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 |
* | 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 |
* ~~ ~~
* __ __
* | 1 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 |
* | 0 1 0 0 0 0 0 0 167 100 5 41 159 169 217 208 |
* | 0 0 1 0 0 0 0 0 166 100 4 40 158 168 216 209 |
* | 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 0 |
* | 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 |
* | 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 |
* | 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 |
* | 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 |
* ~~ ~~
* __ __
* | 0 0 1 0 0 0 0 0 |
* | 167 100 5 41 159 169 217 208 |
* | 166 100 4 40 158 168 216 209 |
* (V|I)'^-1 = | 0 0 0 1 0 0 0 0 |
* | 0 0 0 0 1 0 0 0 |
* | 0 0 0 0 0 1 0 0 |
* | 0 0 0 0 0 0 1 0 |
* | 0 0 0 0 0 0 0 1 |
* ~~ ~~
*
* We can then simply compute D = (V|I)'^-1 x (d|p)' to discover the values
* of the missing data.
*
* As is apparent from the example above, the only non-trivial rows in the
* inverse matrix correspond to the data disks that we're trying to
* reconstruct. Indeed, those are the only rows we need as the others would
* only be useful for reconstructing data known or assumed to be valid. For
* that reason, we only build the coefficients in the rows that correspond to
* targeted columns.
*/
static void
vdev_raidz_matrix_init(raidz_row_t *rr, int n, int nmap, int *map,
uint8_t **rows)
{
int i, j;
int pow;
ASSERT(n == rr->rr_cols - rr->rr_firstdatacol);
/*
* Fill in the missing rows of interest.
*/
for (i = 0; i < nmap; i++) {
ASSERT3S(0, <=, map[i]);
ASSERT3S(map[i], <=, 2);
pow = map[i] * n;
if (pow > 255)
pow -= 255;
ASSERT(pow <= 255);
for (j = 0; j < n; j++) {
pow -= map[i];
if (pow < 0)
pow += 255;
rows[i][j] = vdev_raidz_pow2[pow];
}
}
}
static void
vdev_raidz_matrix_invert(raidz_row_t *rr, int n, int nmissing, int *missing,
uint8_t **rows, uint8_t **invrows, const uint8_t *used)
{
int i, j, ii, jj;
uint8_t log;
/*
* Assert that the first nmissing entries from the array of used
* columns correspond to parity columns and that subsequent entries
* correspond to data columns.
*/
for (i = 0; i < nmissing; i++) {
ASSERT3S(used[i], <, rr->rr_firstdatacol);
}
for (; i < n; i++) {
ASSERT3S(used[i], >=, rr->rr_firstdatacol);
}
/*
* First initialize the storage where we'll compute the inverse rows.
*/
for (i = 0; i < nmissing; i++) {
for (j = 0; j < n; j++) {
invrows[i][j] = (i == j) ? 1 : 0;
}
}
/*
* Subtract all trivial rows from the rows of consequence.
*/
for (i = 0; i < nmissing; i++) {
for (j = nmissing; j < n; j++) {
ASSERT3U(used[j], >=, rr->rr_firstdatacol);
jj = used[j] - rr->rr_firstdatacol;
ASSERT3S(jj, <, n);
invrows[i][j] = rows[i][jj];
rows[i][jj] = 0;
}
}
/*
* For each of the rows of interest, we must normalize it and subtract
* a multiple of it from the other rows.
*/
for (i = 0; i < nmissing; i++) {
for (j = 0; j < missing[i]; j++) {
ASSERT0(rows[i][j]);
}
ASSERT3U(rows[i][missing[i]], !=, 0);
/*
* Compute the inverse of the first element and multiply each
* element in the row by that value.
*/
log = 255 - vdev_raidz_log2[rows[i][missing[i]]];
for (j = 0; j < n; j++) {
rows[i][j] = vdev_raidz_exp2(rows[i][j], log);
invrows[i][j] = vdev_raidz_exp2(invrows[i][j], log);
}
for (ii = 0; ii < nmissing; ii++) {
if (i == ii)
continue;
ASSERT3U(rows[ii][missing[i]], !=, 0);
log = vdev_raidz_log2[rows[ii][missing[i]]];
for (j = 0; j < n; j++) {
rows[ii][j] ^=
vdev_raidz_exp2(rows[i][j], log);
invrows[ii][j] ^=
vdev_raidz_exp2(invrows[i][j], log);
}
}
}
/*
* Verify that the data that is left in the rows are properly part of
* an identity matrix.
*/
for (i = 0; i < nmissing; i++) {
for (j = 0; j < n; j++) {
if (j == missing[i]) {
ASSERT3U(rows[i][j], ==, 1);
} else {
ASSERT0(rows[i][j]);
}
}
}
}
static void
vdev_raidz_matrix_reconstruct(raidz_row_t *rr, int n, int nmissing,
int *missing, uint8_t **invrows, const uint8_t *used)
{
int i, j, x, cc, c;
uint8_t *src;
uint64_t ccount;
uint8_t *dst[VDEV_RAIDZ_MAXPARITY] = { NULL };
uint64_t dcount[VDEV_RAIDZ_MAXPARITY] = { 0 };
uint8_t log = 0;
uint8_t val;
int ll;
uint8_t *invlog[VDEV_RAIDZ_MAXPARITY];
uint8_t *p, *pp;
size_t psize;
psize = sizeof (invlog[0][0]) * n * nmissing;
p = kmem_alloc(psize, KM_SLEEP);
for (pp = p, i = 0; i < nmissing; i++) {
invlog[i] = pp;
pp += n;
}
for (i = 0; i < nmissing; i++) {
for (j = 0; j < n; j++) {
ASSERT3U(invrows[i][j], !=, 0);
invlog[i][j] = vdev_raidz_log2[invrows[i][j]];
}
}
for (i = 0; i < n; i++) {
c = used[i];
ASSERT3U(c, <, rr->rr_cols);
ccount = rr->rr_col[c].rc_size;
ASSERT(ccount >= rr->rr_col[missing[0]].rc_size || i > 0);
if (ccount == 0)
continue;
src = abd_to_buf(rr->rr_col[c].rc_abd);
for (j = 0; j < nmissing; j++) {
cc = missing[j] + rr->rr_firstdatacol;
ASSERT3U(cc, >=, rr->rr_firstdatacol);
ASSERT3U(cc, <, rr->rr_cols);
ASSERT3U(cc, !=, c);
dcount[j] = rr->rr_col[cc].rc_size;
if (dcount[j] != 0)
dst[j] = abd_to_buf(rr->rr_col[cc].rc_abd);
}
for (x = 0; x < ccount; x++, src++) {
if (*src != 0)
log = vdev_raidz_log2[*src];
for (cc = 0; cc < nmissing; cc++) {
if (x >= dcount[cc])
continue;
if (*src == 0) {
val = 0;
} else {
if ((ll = log + invlog[cc][i]) >= 255)
ll -= 255;
val = vdev_raidz_pow2[ll];
}
if (i == 0)
dst[cc][x] = val;
else
dst[cc][x] ^= val;
}
}
}
kmem_free(p, psize);
}
static void
vdev_raidz_reconstruct_general(raidz_row_t *rr, int *tgts, int ntgts)
{
int i, c, t, tt;
unsigned int n;
unsigned int nmissing_rows;
int missing_rows[VDEV_RAIDZ_MAXPARITY];
int parity_map[VDEV_RAIDZ_MAXPARITY];
uint8_t *p, *pp;
size_t psize;
uint8_t *rows[VDEV_RAIDZ_MAXPARITY];
uint8_t *invrows[VDEV_RAIDZ_MAXPARITY];
uint8_t *used;
abd_t **bufs = NULL;
if (zfs_flags & ZFS_DEBUG_RAIDZ_RECONSTRUCT)
zfs_dbgmsg("reconstruct_general(rm=%px ntgts=%u)", rr, ntgts);
/*
* Matrix reconstruction can't use scatter ABDs yet, so we allocate
* temporary linear ABDs if any non-linear ABDs are found.
*/
for (i = rr->rr_firstdatacol; i < rr->rr_cols; i++) {
ASSERT(rr->rr_col[i].rc_abd != NULL);
if (!abd_is_linear(rr->rr_col[i].rc_abd)) {
bufs = kmem_alloc(rr->rr_cols * sizeof (abd_t *),
KM_PUSHPAGE);
for (c = rr->rr_firstdatacol; c < rr->rr_cols; c++) {
raidz_col_t *col = &rr->rr_col[c];
bufs[c] = col->rc_abd;
if (bufs[c] != NULL) {
col->rc_abd = abd_alloc_linear(
col->rc_size, B_TRUE);
abd_copy(col->rc_abd, bufs[c],
col->rc_size);
}
}
break;
}
}
n = rr->rr_cols - rr->rr_firstdatacol;
/*
* Figure out which data columns are missing.
*/
nmissing_rows = 0;
for (t = 0; t < ntgts; t++) {
if (tgts[t] >= rr->rr_firstdatacol) {
missing_rows[nmissing_rows++] =
tgts[t] - rr->rr_firstdatacol;
}
}
/*
* Figure out which parity columns to use to help generate the missing
* data columns.
*/
for (tt = 0, c = 0, i = 0; i < nmissing_rows; c++) {
ASSERT(tt < ntgts);
ASSERT(c < rr->rr_firstdatacol);
/*
* Skip any targeted parity columns.
*/
if (c == tgts[tt]) {
tt++;
continue;
}
parity_map[i] = c;
i++;
}
psize = (sizeof (rows[0][0]) + sizeof (invrows[0][0])) *
nmissing_rows * n + sizeof (used[0]) * n;
p = kmem_alloc(psize, KM_SLEEP);
for (pp = p, i = 0; i < nmissing_rows; i++) {
rows[i] = pp;
pp += n;
invrows[i] = pp;
pp += n;
}
used = pp;
for (i = 0; i < nmissing_rows; i++) {
used[i] = parity_map[i];
}
for (tt = 0, c = rr->rr_firstdatacol; c < rr->rr_cols; c++) {
if (tt < nmissing_rows &&
c == missing_rows[tt] + rr->rr_firstdatacol) {
tt++;
continue;
}
ASSERT3S(i, <, n);
used[i] = c;
i++;
}
/*
* Initialize the interesting rows of the matrix.
*/
vdev_raidz_matrix_init(rr, n, nmissing_rows, parity_map, rows);
/*
* Invert the matrix.
*/
vdev_raidz_matrix_invert(rr, n, nmissing_rows, missing_rows, rows,
invrows, used);
/*
* Reconstruct the missing data using the generated matrix.
*/
vdev_raidz_matrix_reconstruct(rr, n, nmissing_rows, missing_rows,
invrows, used);
kmem_free(p, psize);
/*
* copy back from temporary linear abds and free them
*/
if (bufs) {
for (c = rr->rr_firstdatacol; c < rr->rr_cols; c++) {
raidz_col_t *col = &rr->rr_col[c];
if (bufs[c] != NULL) {
abd_copy(bufs[c], col->rc_abd, col->rc_size);
abd_free(col->rc_abd);
}
col->rc_abd = bufs[c];
}
kmem_free(bufs, rr->rr_cols * sizeof (abd_t *));
}
}
static void
vdev_raidz_reconstruct_row(raidz_map_t *rm, raidz_row_t *rr,
const int *t, int nt)
{
int tgts[VDEV_RAIDZ_MAXPARITY], *dt;
int ntgts;
int i, c, ret;
int nbadparity, nbaddata;
int parity_valid[VDEV_RAIDZ_MAXPARITY];
if (zfs_flags & ZFS_DEBUG_RAIDZ_RECONSTRUCT) {
zfs_dbgmsg("reconstruct(rm=%px nt=%u cols=%u md=%u mp=%u)",
rr, nt, (int)rr->rr_cols, (int)rr->rr_missingdata,
(int)rr->rr_missingparity);
}
nbadparity = rr->rr_firstdatacol;
nbaddata = rr->rr_cols - nbadparity;
ntgts = 0;
for (i = 0, c = 0; c < rr->rr_cols; c++) {
if (zfs_flags & ZFS_DEBUG_RAIDZ_RECONSTRUCT) {
zfs_dbgmsg("reconstruct(rm=%px col=%u devid=%u "
"offset=%llx error=%u)",
rr, c, (int)rr->rr_col[c].rc_devidx,
(long long)rr->rr_col[c].rc_offset,
(int)rr->rr_col[c].rc_error);
}
if (c < rr->rr_firstdatacol)
parity_valid[c] = B_FALSE;
if (i < nt && c == t[i]) {
tgts[ntgts++] = c;
i++;
} else if (rr->rr_col[c].rc_error != 0) {
tgts[ntgts++] = c;
} else if (c >= rr->rr_firstdatacol) {
nbaddata--;
} else {
parity_valid[c] = B_TRUE;
nbadparity--;
}
}
ASSERT(ntgts >= nt);
ASSERT(nbaddata >= 0);
ASSERT(nbaddata + nbadparity == ntgts);
dt = &tgts[nbadparity];
/* Reconstruct using the new math implementation */
ret = vdev_raidz_math_reconstruct(rm, rr, parity_valid, dt, nbaddata);
if (ret != RAIDZ_ORIGINAL_IMPL)
return;
/*
* See if we can use any of our optimized reconstruction routines.
*/
switch (nbaddata) {
case 1:
if (parity_valid[VDEV_RAIDZ_P]) {
vdev_raidz_reconstruct_p(rr, dt, 1);
return;
}
ASSERT(rr->rr_firstdatacol > 1);
if (parity_valid[VDEV_RAIDZ_Q]) {
vdev_raidz_reconstruct_q(rr, dt, 1);
return;
}
ASSERT(rr->rr_firstdatacol > 2);
break;
case 2:
ASSERT(rr->rr_firstdatacol > 1);
if (parity_valid[VDEV_RAIDZ_P] &&
parity_valid[VDEV_RAIDZ_Q]) {
vdev_raidz_reconstruct_pq(rr, dt, 2);
return;
}
ASSERT(rr->rr_firstdatacol > 2);
break;
}
vdev_raidz_reconstruct_general(rr, tgts, ntgts);
}
static int
vdev_raidz_open(vdev_t *vd, uint64_t *asize, uint64_t *max_asize,
uint64_t *logical_ashift, uint64_t *physical_ashift)
{
vdev_raidz_t *vdrz = vd->vdev_tsd;
uint64_t nparity = vdrz->vd_nparity;
int c;
int lasterror = 0;
int numerrors = 0;
ASSERT(nparity > 0);
if (nparity > VDEV_RAIDZ_MAXPARITY ||
vd->vdev_children < nparity + 1) {
vd->vdev_stat.vs_aux = VDEV_AUX_BAD_LABEL;
return (SET_ERROR(EINVAL));
}
vdev_open_children(vd);
for (c = 0; c < vd->vdev_children; c++) {
vdev_t *cvd = vd->vdev_child[c];
if (cvd->vdev_open_error != 0) {
lasterror = cvd->vdev_open_error;
numerrors++;
continue;
}
*asize = MIN(*asize - 1, cvd->vdev_asize - 1) + 1;
*max_asize = MIN(*max_asize - 1, cvd->vdev_max_asize - 1) + 1;
*logical_ashift = MAX(*logical_ashift, cvd->vdev_ashift);
}
for (c = 0; c < vd->vdev_children; c++) {
vdev_t *cvd = vd->vdev_child[c];
if (cvd->vdev_open_error != 0)
continue;
*physical_ashift = vdev_best_ashift(*logical_ashift,
*physical_ashift, cvd->vdev_physical_ashift);
}
if (vd->vdev_rz_expanding) {
*asize *= vd->vdev_children - 1;
*max_asize *= vd->vdev_children - 1;
vd->vdev_min_asize = *asize;
} else {
*asize *= vd->vdev_children;
*max_asize *= vd->vdev_children;
}
if (numerrors > nparity) {
vd->vdev_stat.vs_aux = VDEV_AUX_NO_REPLICAS;
return (lasterror);
}
return (0);
}
static void
vdev_raidz_close(vdev_t *vd)
{
for (int c = 0; c < vd->vdev_children; c++) {
if (vd->vdev_child[c] != NULL)
vdev_close(vd->vdev_child[c]);
}
}
/*
* Return the logical width to use, given the txg in which the allocation
* happened. Note that BP_GET_BIRTH() is usually the txg in which the
* BP was allocated. Remapped BP's (that were relocated due to device
* removal, see remap_blkptr_cb()), will have a more recent physical birth
* which reflects when the BP was relocated, but we can ignore these because
* they can't be on RAIDZ (device removal doesn't support RAIDZ).
*/
static uint64_t
vdev_raidz_get_logical_width(vdev_raidz_t *vdrz, uint64_t txg)
{
reflow_node_t lookup = {
.re_txg = txg,
};
avl_index_t where;
uint64_t width;
mutex_enter(&vdrz->vd_expand_lock);
reflow_node_t *re = avl_find(&vdrz->vd_expand_txgs, &lookup, &where);
if (re != NULL) {
width = re->re_logical_width;
} else {
re = avl_nearest(&vdrz->vd_expand_txgs, where, AVL_BEFORE);
if (re != NULL)
width = re->re_logical_width;
else
width = vdrz->vd_original_width;
}
mutex_exit(&vdrz->vd_expand_lock);
return (width);
}
/*
* Note: If the RAIDZ vdev has been expanded, older BP's may have allocated
* more space due to the lower data-to-parity ratio. In this case it's
* important to pass in the correct txg. Note that vdev_gang_header_asize()
* relies on a constant asize for psize=SPA_GANGBLOCKSIZE=SPA_MINBLOCKSIZE,
* regardless of txg. This is assured because for a single data sector, we
* allocate P+1 sectors regardless of width ("cols", which is at least P+1).
*/
static uint64_t
vdev_raidz_asize(vdev_t *vd, uint64_t psize, uint64_t txg)
{
vdev_raidz_t *vdrz = vd->vdev_tsd;
uint64_t asize;
uint64_t ashift = vd->vdev_top->vdev_ashift;
uint64_t cols = vdrz->vd_original_width;
uint64_t nparity = vdrz->vd_nparity;
cols = vdev_raidz_get_logical_width(vdrz, txg);
asize = ((psize - 1) >> ashift) + 1;
asize += nparity * ((asize + cols - nparity - 1) / (cols - nparity));
asize = roundup(asize, nparity + 1) << ashift;
#ifdef ZFS_DEBUG
uint64_t asize_new = ((psize - 1) >> ashift) + 1;
uint64_t ncols_new = vdrz->vd_physical_width;
asize_new += nparity * ((asize_new + ncols_new - nparity - 1) /
(ncols_new - nparity));
asize_new = roundup(asize_new, nparity + 1) << ashift;
VERIFY3U(asize_new, <=, asize);
#endif
return (asize);
}
/*
* The allocatable space for a raidz vdev is N * sizeof(smallest child)
* so each child must provide at least 1/Nth of its asize.
*/
static uint64_t
vdev_raidz_min_asize(vdev_t *vd)
{
return ((vd->vdev_min_asize + vd->vdev_children - 1) /
vd->vdev_children);
}
void
vdev_raidz_child_done(zio_t *zio)
{
raidz_col_t *rc = zio->io_private;
ASSERT3P(rc->rc_abd, !=, NULL);
rc->rc_error = zio->io_error;
rc->rc_tried = 1;
rc->rc_skipped = 0;
}
static void
vdev_raidz_shadow_child_done(zio_t *zio)
{
raidz_col_t *rc = zio->io_private;
rc->rc_shadow_error = zio->io_error;
}
static void
vdev_raidz_io_verify(zio_t *zio, raidz_map_t *rm, raidz_row_t *rr, int col)
{
(void) rm;
#ifdef ZFS_DEBUG
range_seg64_t logical_rs, physical_rs, remain_rs;
logical_rs.rs_start = rr->rr_offset;
logical_rs.rs_end = logical_rs.rs_start +
vdev_raidz_asize(zio->io_vd, rr->rr_size,
BP_GET_BIRTH(zio->io_bp));
raidz_col_t *rc = &rr->rr_col[col];
vdev_t *cvd = zio->io_vd->vdev_child[rc->rc_devidx];
vdev_xlate(cvd, &logical_rs, &physical_rs, &remain_rs);
ASSERT(vdev_xlate_is_empty(&remain_rs));
if (vdev_xlate_is_empty(&physical_rs)) {
/*
* If we are in the middle of expansion, the
* physical->logical mapping is changing so vdev_xlate()
* can't give us a reliable answer.
*/
return;
}
ASSERT3U(rc->rc_offset, ==, physical_rs.rs_start);
ASSERT3U(rc->rc_offset, <, physical_rs.rs_end);
/*
* It would be nice to assert that rs_end is equal
* to rc_offset + rc_size but there might be an
* optional I/O at the end that is not accounted in
* rc_size.
*/
if (physical_rs.rs_end > rc->rc_offset + rc->rc_size) {
ASSERT3U(physical_rs.rs_end, ==, rc->rc_offset +
rc->rc_size + (1 << zio->io_vd->vdev_top->vdev_ashift));
} else {
ASSERT3U(physical_rs.rs_end, ==, rc->rc_offset + rc->rc_size);
}
#endif
}
static void
vdev_raidz_io_start_write(zio_t *zio, raidz_row_t *rr)
{
vdev_t *vd = zio->io_vd;
raidz_map_t *rm = zio->io_vsd;
vdev_raidz_generate_parity_row(rm, rr);
for (int c = 0; c < rr->rr_scols; c++) {
raidz_col_t *rc = &rr->rr_col[c];
vdev_t *cvd = vd->vdev_child[rc->rc_devidx];
/* Verify physical to logical translation */
vdev_raidz_io_verify(zio, rm, rr, c);
if (rc->rc_size == 0)
continue;
ASSERT3U(rc->rc_offset + rc->rc_size, <,
cvd->vdev_psize - VDEV_LABEL_END_SIZE);
ASSERT3P(rc->rc_abd, !=, NULL);
zio_nowait(zio_vdev_child_io(zio, NULL, cvd,
rc->rc_offset, rc->rc_abd,
abd_get_size(rc->rc_abd), zio->io_type,
zio->io_priority, 0, vdev_raidz_child_done, rc));
if (rc->rc_shadow_devidx != INT_MAX) {
vdev_t *cvd2 = vd->vdev_child[rc->rc_shadow_devidx];
ASSERT3U(
rc->rc_shadow_offset + abd_get_size(rc->rc_abd), <,
cvd2->vdev_psize - VDEV_LABEL_END_SIZE);
zio_nowait(zio_vdev_child_io(zio, NULL, cvd2,
rc->rc_shadow_offset, rc->rc_abd,
abd_get_size(rc->rc_abd),
zio->io_type, zio->io_priority, 0,
vdev_raidz_shadow_child_done, rc));
}
}
}
/*
* Generate optional I/Os for skip sectors to improve aggregation contiguity.
* This only works for vdev_raidz_map_alloc() (not _expanded()).
*/
static void
raidz_start_skip_writes(zio_t *zio)
{
vdev_t *vd = zio->io_vd;
uint64_t ashift = vd->vdev_top->vdev_ashift;
raidz_map_t *rm = zio->io_vsd;
ASSERT3U(rm->rm_nrows, ==, 1);
raidz_row_t *rr = rm->rm_row[0];
for (int c = 0; c < rr->rr_scols; c++) {
raidz_col_t *rc = &rr->rr_col[c];
vdev_t *cvd = vd->vdev_child[rc->rc_devidx];
if (rc->rc_size != 0)
continue;
ASSERT3P(rc->rc_abd, ==, NULL);
ASSERT3U(rc->rc_offset, <,
cvd->vdev_psize - VDEV_LABEL_END_SIZE);
zio_nowait(zio_vdev_child_io(zio, NULL, cvd, rc->rc_offset,
NULL, 1ULL << ashift, zio->io_type, zio->io_priority,
ZIO_FLAG_NODATA | ZIO_FLAG_OPTIONAL, NULL, NULL));
}
}
static void
vdev_raidz_io_start_read_row(zio_t *zio, raidz_row_t *rr, boolean_t forceparity)
{
vdev_t *vd = zio->io_vd;
/*
* Iterate over the columns in reverse order so that we hit the parity
* last -- any errors along the way will force us to read the parity.
*/
for (int c = rr->rr_cols - 1; c >= 0; c--) {
raidz_col_t *rc = &rr->rr_col[c];
if (rc->rc_size == 0)
continue;
vdev_t *cvd = vd->vdev_child[rc->rc_devidx];
if (!vdev_readable(cvd)) {
if (c >= rr->rr_firstdatacol)
rr->rr_missingdata++;
else
rr->rr_missingparity++;
rc->rc_error = SET_ERROR(ENXIO);
rc->rc_tried = 1; /* don't even try */
rc->rc_skipped = 1;
continue;
}
if (vdev_dtl_contains(cvd, DTL_MISSING, zio->io_txg, 1)) {
if (c >= rr->rr_firstdatacol)
rr->rr_missingdata++;
else
rr->rr_missingparity++;
rc->rc_error = SET_ERROR(ESTALE);
rc->rc_skipped = 1;
continue;
}
if (forceparity ||
c >= rr->rr_firstdatacol || rr->rr_missingdata > 0 ||
(zio->io_flags & (ZIO_FLAG_SCRUB | ZIO_FLAG_RESILVER))) {
zio_nowait(zio_vdev_child_io(zio, NULL, cvd,
rc->rc_offset, rc->rc_abd, rc->rc_size,
zio->io_type, zio->io_priority, 0,
vdev_raidz_child_done, rc));
}
}
}
static void
vdev_raidz_io_start_read_phys_cols(zio_t *zio, raidz_map_t *rm)
{
vdev_t *vd = zio->io_vd;
for (int i = 0; i < rm->rm_nphys_cols; i++) {
raidz_col_t *prc = &rm->rm_phys_col[i];
if (prc->rc_size == 0)
continue;
ASSERT3U(prc->rc_devidx, ==, i);
vdev_t *cvd = vd->vdev_child[i];
if (!vdev_readable(cvd)) {
prc->rc_error = SET_ERROR(ENXIO);
prc->rc_tried = 1; /* don't even try */
prc->rc_skipped = 1;
continue;
}
if (vdev_dtl_contains(cvd, DTL_MISSING, zio->io_txg, 1)) {
prc->rc_error = SET_ERROR(ESTALE);
prc->rc_skipped = 1;
continue;
}
zio_nowait(zio_vdev_child_io(zio, NULL, cvd,
prc->rc_offset, prc->rc_abd, prc->rc_size,
zio->io_type, zio->io_priority, 0,
vdev_raidz_child_done, prc));
}
}
static void
vdev_raidz_io_start_read(zio_t *zio, raidz_map_t *rm)
{
/*
* If there are multiple rows, we will be hitting
* all disks, so go ahead and read the parity so
* that we are reading in decent size chunks.
*/
boolean_t forceparity = rm->rm_nrows > 1;
if (rm->rm_phys_col) {
vdev_raidz_io_start_read_phys_cols(zio, rm);
} else {
for (int i = 0; i < rm->rm_nrows; i++) {
raidz_row_t *rr = rm->rm_row[i];
vdev_raidz_io_start_read_row(zio, rr, forceparity);
}
}
}
/*
* Start an IO operation on a RAIDZ VDev
*
* Outline:
* - For write operations:
* 1. Generate the parity data
* 2. Create child zio write operations to each column's vdev, for both
* data and parity.
* 3. If the column skips any sectors for padding, create optional dummy
* write zio children for those areas to improve aggregation continuity.
* - For read operations:
* 1. Create child zio read operations to each data column's vdev to read
* the range of data required for zio.
* 2. If this is a scrub or resilver operation, or if any of the data
* vdevs have had errors, then create zio read operations to the parity
* columns' VDevs as well.
*/
static void
vdev_raidz_io_start(zio_t *zio)
{
vdev_t *vd = zio->io_vd;
vdev_t *tvd = vd->vdev_top;
vdev_raidz_t *vdrz = vd->vdev_tsd;
raidz_map_t *rm;
uint64_t logical_width = vdev_raidz_get_logical_width(vdrz,
BP_GET_BIRTH(zio->io_bp));
if (logical_width != vdrz->vd_physical_width) {
zfs_locked_range_t *lr = NULL;
uint64_t synced_offset = UINT64_MAX;
uint64_t next_offset = UINT64_MAX;
boolean_t use_scratch = B_FALSE;
/*
* Note: when the expansion is completing, we set
* vre_state=DSS_FINISHED (in raidz_reflow_complete_sync())
* in a later txg than when we last update spa_ubsync's state
* (see the end of spa_raidz_expand_thread()). Therefore we
* may see vre_state!=SCANNING before
* VDEV_TOP_ZAP_RAIDZ_EXPAND_STATE=DSS_FINISHED is reflected
* on disk, but the copying progress has been synced to disk
* (and reflected in spa_ubsync). In this case it's fine to
* treat the expansion as completed, since if we crash there's
* no additional copying to do.
*/
if (vdrz->vn_vre.vre_state == DSS_SCANNING) {
ASSERT3P(vd->vdev_spa->spa_raidz_expand, ==,
&vdrz->vn_vre);
lr = zfs_rangelock_enter(&vdrz->vn_vre.vre_rangelock,
zio->io_offset, zio->io_size, RL_READER);
use_scratch =
(RRSS_GET_STATE(&vd->vdev_spa->spa_ubsync) ==
RRSS_SCRATCH_VALID);
synced_offset =
RRSS_GET_OFFSET(&vd->vdev_spa->spa_ubsync);
next_offset = vdrz->vn_vre.vre_offset;
/*
* If we haven't resumed expanding since importing the
* pool, vre_offset won't have been set yet. In
* this case the next offset to be copied is the same
* as what was synced.
*/
if (next_offset == UINT64_MAX) {
next_offset = synced_offset;
}
}
if (use_scratch) {
zfs_dbgmsg("zio=%px %s io_offset=%llu offset_synced="
"%lld next_offset=%lld use_scratch=%u",
zio,
zio->io_type == ZIO_TYPE_WRITE ? "WRITE" : "READ",
(long long)zio->io_offset,
(long long)synced_offset,
(long long)next_offset,
use_scratch);
}
rm = vdev_raidz_map_alloc_expanded(zio,
tvd->vdev_ashift, vdrz->vd_physical_width,
logical_width, vdrz->vd_nparity,
synced_offset, next_offset, use_scratch);
rm->rm_lr = lr;
} else {
rm = vdev_raidz_map_alloc(zio,
tvd->vdev_ashift, logical_width, vdrz->vd_nparity);
}
rm->rm_original_width = vdrz->vd_original_width;
zio->io_vsd = rm;
zio->io_vsd_ops = &vdev_raidz_vsd_ops;
if (zio->io_type == ZIO_TYPE_WRITE) {
for (int i = 0; i < rm->rm_nrows; i++) {
vdev_raidz_io_start_write(zio, rm->rm_row[i]);
}
if (logical_width == vdrz->vd_physical_width) {
raidz_start_skip_writes(zio);
}
} else {
ASSERT(zio->io_type == ZIO_TYPE_READ);
vdev_raidz_io_start_read(zio, rm);
}
zio_execute(zio);
}
/*
* Report a checksum error for a child of a RAID-Z device.
*/
void
vdev_raidz_checksum_error(zio_t *zio, raidz_col_t *rc, abd_t *bad_data)
{
vdev_t *vd = zio->io_vd->vdev_child[rc->rc_devidx];
if (!(zio->io_flags & ZIO_FLAG_SPECULATIVE) &&
zio->io_priority != ZIO_PRIORITY_REBUILD) {
zio_bad_cksum_t zbc;
raidz_map_t *rm = zio->io_vsd;
zbc.zbc_has_cksum = 0;
zbc.zbc_injected = rm->rm_ecksuminjected;
mutex_enter(&vd->vdev_stat_lock);
vd->vdev_stat.vs_checksum_errors++;
mutex_exit(&vd->vdev_stat_lock);
(void) zfs_ereport_post_checksum(zio->io_spa, vd,
&zio->io_bookmark, zio, rc->rc_offset, rc->rc_size,
rc->rc_abd, bad_data, &zbc);
}
}
/*
* We keep track of whether or not there were any injected errors, so that
* any ereports we generate can note it.
*/
static int
raidz_checksum_verify(zio_t *zio)
{
zio_bad_cksum_t zbc = {0};
raidz_map_t *rm = zio->io_vsd;
int ret = zio_checksum_error(zio, &zbc);
if (ret != 0 && zbc.zbc_injected != 0)
rm->rm_ecksuminjected = 1;
return (ret);
}
/*
* Generate the parity from the data columns. If we tried and were able to
* read the parity without error, verify that the generated parity matches the
* data we read. If it doesn't, we fire off a checksum error. Return the
* number of such failures.
*/
static int
raidz_parity_verify(zio_t *zio, raidz_row_t *rr)
{
abd_t *orig[VDEV_RAIDZ_MAXPARITY];
int c, ret = 0;
raidz_map_t *rm = zio->io_vsd;
raidz_col_t *rc;
blkptr_t *bp = zio->io_bp;
enum zio_checksum checksum = (bp == NULL ? zio->io_prop.zp_checksum :
(BP_IS_GANG(bp) ? ZIO_CHECKSUM_GANG_HEADER : BP_GET_CHECKSUM(bp)));
if (checksum == ZIO_CHECKSUM_NOPARITY)
return (ret);
for (c = 0; c < rr->rr_firstdatacol; c++) {
rc = &rr->rr_col[c];
if (!rc->rc_tried || rc->rc_error != 0)
continue;
orig[c] = rc->rc_abd;
ASSERT3U(abd_get_size(rc->rc_abd), ==, rc->rc_size);
rc->rc_abd = abd_alloc_linear(rc->rc_size, B_FALSE);
}
/*
* Verify any empty sectors are zero filled to ensure the parity
* is calculated correctly even if these non-data sectors are damaged.
*/
if (rr->rr_nempty && rr->rr_abd_empty != NULL)
ret += vdev_draid_map_verify_empty(zio, rr);
/*
* Regenerates parity even for !tried||rc_error!=0 columns. This
* isn't harmful but it does have the side effect of fixing stuff
* we didn't realize was necessary (i.e. even if we return 0).
*/
vdev_raidz_generate_parity_row(rm, rr);
for (c = 0; c < rr->rr_firstdatacol; c++) {
rc = &rr->rr_col[c];
if (!rc->rc_tried || rc->rc_error != 0)
continue;
if (abd_cmp(orig[c], rc->rc_abd) != 0) {
zfs_dbgmsg("found error on col=%u devidx=%u off %llx",
c, (int)rc->rc_devidx, (u_longlong_t)rc->rc_offset);
vdev_raidz_checksum_error(zio, rc, orig[c]);
rc->rc_error = SET_ERROR(ECKSUM);
ret++;
}
abd_free(orig[c]);
}
return (ret);
}
static int
vdev_raidz_worst_error(raidz_row_t *rr)
{
int error = 0;
for (int c = 0; c < rr->rr_cols; c++) {
error = zio_worst_error(error, rr->rr_col[c].rc_error);
error = zio_worst_error(error, rr->rr_col[c].rc_shadow_error);
}
return (error);
}
static void
vdev_raidz_io_done_verified(zio_t *zio, raidz_row_t *rr)
{
int unexpected_errors = 0;
int parity_errors = 0;
int parity_untried = 0;
int data_errors = 0;
ASSERT3U(zio->io_type, ==, ZIO_TYPE_READ);
for (int c = 0; c < rr->rr_cols; c++) {
raidz_col_t *rc = &rr->rr_col[c];
if (rc->rc_error) {
if (c < rr->rr_firstdatacol)
parity_errors++;
else
data_errors++;
if (!rc->rc_skipped)
unexpected_errors++;
} else if (c < rr->rr_firstdatacol && !rc->rc_tried) {
parity_untried++;
}
if (rc->rc_force_repair)
unexpected_errors++;
}
/*
* If we read more parity disks than were used for
* reconstruction, confirm that the other parity disks produced
* correct data.
*
* Note that we also regenerate parity when resilvering so we
* can write it out to failed devices later.
*/
if (parity_errors + parity_untried <
rr->rr_firstdatacol - data_errors ||
(zio->io_flags & ZIO_FLAG_RESILVER)) {
int n = raidz_parity_verify(zio, rr);
unexpected_errors += n;
}
if (zio->io_error == 0 && spa_writeable(zio->io_spa) &&
(unexpected_errors > 0 || (zio->io_flags & ZIO_FLAG_RESILVER))) {
/*
* Use the good data we have in hand to repair damaged children.
*/
for (int c = 0; c < rr->rr_cols; c++) {
raidz_col_t *rc = &rr->rr_col[c];
vdev_t *vd = zio->io_vd;
vdev_t *cvd = vd->vdev_child[rc->rc_devidx];
if (!rc->rc_allow_repair) {
continue;
} else if (!rc->rc_force_repair &&
(rc->rc_error == 0 || rc->rc_size == 0)) {
continue;
}
zfs_dbgmsg("zio=%px repairing c=%u devidx=%u "
"offset=%llx",
zio, c, rc->rc_devidx, (long long)rc->rc_offset);
zio_nowait(zio_vdev_child_io(zio, NULL, cvd,
rc->rc_offset, rc->rc_abd, rc->rc_size,
ZIO_TYPE_WRITE,
zio->io_priority == ZIO_PRIORITY_REBUILD ?
ZIO_PRIORITY_REBUILD : ZIO_PRIORITY_ASYNC_WRITE,
ZIO_FLAG_IO_REPAIR | (unexpected_errors ?
ZIO_FLAG_SELF_HEAL : 0), NULL, NULL));
}
}
/*
* Scrub or resilver i/o's: overwrite any shadow locations with the
* good data. This ensures that if we've already copied this sector,
* it will be corrected if it was damaged. This writes more than is
* necessary, but since expansion is paused during scrub/resilver, at
* most a single row will have a shadow location.
*/
if (zio->io_error == 0 && spa_writeable(zio->io_spa) &&
(zio->io_flags & (ZIO_FLAG_RESILVER | ZIO_FLAG_SCRUB))) {
for (int c = 0; c < rr->rr_cols; c++) {
raidz_col_t *rc = &rr->rr_col[c];
vdev_t *vd = zio->io_vd;
if (rc->rc_shadow_devidx == INT_MAX || rc->rc_size == 0)
continue;
vdev_t *cvd = vd->vdev_child[rc->rc_shadow_devidx];
/*
* Note: We don't want to update the repair stats
* because that would incorrectly indicate that there
* was bad data to repair, which we aren't sure about.
* By clearing the SCAN_THREAD flag, we prevent this
* from happening, despite having the REPAIR flag set.
* We need to set SELF_HEAL so that this i/o can't be
* bypassed by zio_vdev_io_start().
*/
zio_t *cio = zio_vdev_child_io(zio, NULL, cvd,
rc->rc_shadow_offset, rc->rc_abd, rc->rc_size,
ZIO_TYPE_WRITE, ZIO_PRIORITY_ASYNC_WRITE,
ZIO_FLAG_IO_REPAIR | ZIO_FLAG_SELF_HEAL,
NULL, NULL);
cio->io_flags &= ~ZIO_FLAG_SCAN_THREAD;
zio_nowait(cio);
}
}
}
static void
raidz_restore_orig_data(raidz_map_t *rm)
{
for (int i = 0; i < rm->rm_nrows; i++) {
raidz_row_t *rr = rm->rm_row[i];
for (int c = 0; c < rr->rr_cols; c++) {
raidz_col_t *rc = &rr->rr_col[c];
if (rc->rc_need_orig_restore) {
abd_copy(rc->rc_abd,
rc->rc_orig_data, rc->rc_size);
rc->rc_need_orig_restore = B_FALSE;
}
}
}
}
/*
* During raidz_reconstruct() for expanded VDEV, we need special consideration
* failure simulations. See note in raidz_reconstruct() on simulating failure
* of a pre-expansion device.
*
* Treating logical child i as failed, return TRUE if the given column should
* be treated as failed. The idea of logical children allows us to imagine
* that a disk silently failed before a RAIDZ expansion (reads from this disk
* succeed but return the wrong data). Since the expansion doesn't verify
* checksums, the incorrect data will be moved to new locations spread among
* the children (going diagonally across them).
*
* Higher "logical child failures" (values of `i`) indicate these
* "pre-expansion failures". The first physical_width values imagine that a
* current child failed; the next physical_width-1 values imagine that a
* child failed before the most recent expansion; the next physical_width-2
* values imagine a child failed in the expansion before that, etc.
*/
static boolean_t
raidz_simulate_failure(int physical_width, int original_width, int ashift,
int i, raidz_col_t *rc)
{
uint64_t sector_id =
physical_width * (rc->rc_offset >> ashift) +
rc->rc_devidx;
for (int w = physical_width; w >= original_width; w--) {
if (i < w) {
return (sector_id % w == i);
} else {
i -= w;
}
}
ASSERT(!"invalid logical child id");
return (B_FALSE);
}
/*
* returns EINVAL if reconstruction of the block will not be possible
* returns ECKSUM if this specific reconstruction failed
* returns 0 on successful reconstruction
*/
static int
raidz_reconstruct(zio_t *zio, int *ltgts, int ntgts, int nparity)
{
raidz_map_t *rm = zio->io_vsd;
int physical_width = zio->io_vd->vdev_children;
int original_width = (rm->rm_original_width != 0) ?
rm->rm_original_width : physical_width;
int dbgmsg = zfs_flags & ZFS_DEBUG_RAIDZ_RECONSTRUCT;
if (dbgmsg) {
zfs_dbgmsg("raidz_reconstruct_expanded(zio=%px ltgts=%u,%u,%u "
"ntgts=%u", zio, ltgts[0], ltgts[1], ltgts[2], ntgts);
}
/* Reconstruct each row */
for (int r = 0; r < rm->rm_nrows; r++) {
raidz_row_t *rr = rm->rm_row[r];
int my_tgts[VDEV_RAIDZ_MAXPARITY]; /* value is child id */
int t = 0;
int dead = 0;
int dead_data = 0;
if (dbgmsg)
zfs_dbgmsg("raidz_reconstruct_expanded(row=%u)", r);
for (int c = 0; c < rr->rr_cols; c++) {
raidz_col_t *rc = &rr->rr_col[c];
ASSERT0(rc->rc_need_orig_restore);
if (rc->rc_error != 0) {
dead++;
if (c >= nparity)
dead_data++;
continue;
}
if (rc->rc_size == 0)
continue;
for (int lt = 0; lt < ntgts; lt++) {
if (raidz_simulate_failure(physical_width,
original_width,
zio->io_vd->vdev_top->vdev_ashift,
ltgts[lt], rc)) {
if (rc->rc_orig_data == NULL) {
rc->rc_orig_data =
abd_alloc_linear(
rc->rc_size, B_TRUE);
abd_copy(rc->rc_orig_data,
rc->rc_abd, rc->rc_size);
}
rc->rc_need_orig_restore = B_TRUE;
dead++;
if (c >= nparity)
dead_data++;
/*
* Note: simulating failure of a
* pre-expansion device can hit more
* than one column, in which case we
* might try to simulate more failures
* than can be reconstructed, which is
* also more than the size of my_tgts.
* This check prevents accessing past
* the end of my_tgts. The "dead >
* nparity" check below will fail this
* reconstruction attempt.
*/
if (t < VDEV_RAIDZ_MAXPARITY) {
my_tgts[t++] = c;
if (dbgmsg) {
zfs_dbgmsg("simulating "
"failure of col %u "
"devidx %u", c,
(int)rc->rc_devidx);
}
}
break;
}
}
}
if (dead > nparity) {
/* reconstruction not possible */
if (dbgmsg) {
zfs_dbgmsg("reconstruction not possible; "
"too many failures");
}
raidz_restore_orig_data(rm);
return (EINVAL);
}
if (dead_data > 0)
vdev_raidz_reconstruct_row(rm, rr, my_tgts, t);
}
/* Check for success */
if (raidz_checksum_verify(zio) == 0) {
/* Reconstruction succeeded - report errors */
for (int i = 0; i < rm->rm_nrows; i++) {
raidz_row_t *rr = rm->rm_row[i];
for (int c = 0; c < rr->rr_cols; c++) {
raidz_col_t *rc = &rr->rr_col[c];
if (rc->rc_need_orig_restore) {
/*
* Note: if this is a parity column,
* we don't really know if it's wrong.
* We need to let
* vdev_raidz_io_done_verified() check
* it, and if we set rc_error, it will
* think that it is a "known" error
* that doesn't need to be checked
* or corrected.
*/
if (rc->rc_error == 0 &&
c >= rr->rr_firstdatacol) {
vdev_raidz_checksum_error(zio,
rc, rc->rc_orig_data);
rc->rc_error =
SET_ERROR(ECKSUM);
}
rc->rc_need_orig_restore = B_FALSE;
}
}
vdev_raidz_io_done_verified(zio, rr);
}
zio_checksum_verified(zio);
if (dbgmsg) {
zfs_dbgmsg("reconstruction successful "
"(checksum verified)");
}
return (0);
}
/* Reconstruction failed - restore original data */
raidz_restore_orig_data(rm);
if (dbgmsg) {
zfs_dbgmsg("raidz_reconstruct_expanded(zio=%px) checksum "
"failed", zio);
}
return (ECKSUM);
}
/*
* Iterate over all combinations of N bad vdevs and attempt a reconstruction.
* Note that the algorithm below is non-optimal because it doesn't take into
* account how reconstruction is actually performed. For example, with
* triple-parity RAID-Z the reconstruction procedure is the same if column 4
* is targeted as invalid as if columns 1 and 4 are targeted since in both
* cases we'd only use parity information in column 0.
*
* The order that we find the various possible combinations of failed
* disks is dictated by these rules:
* - Examine each "slot" (the "i" in tgts[i])
* - Try to increment this slot (tgts[i] += 1)
* - if we can't increment because it runs into the next slot,
* reset our slot to the minimum, and examine the next slot
*
* For example, with a 6-wide RAIDZ3, and no known errors (so we have to choose
* 3 columns to reconstruct), we will generate the following sequence:
*
* STATE ACTION
* 0 1 2 special case: skip since these are all parity
* 0 1 3 first slot: reset to 0; middle slot: increment to 2
* 0 2 3 first slot: increment to 1
* 1 2 3 first: reset to 0; middle: reset to 1; last: increment to 4
* 0 1 4 first: reset to 0; middle: increment to 2
* 0 2 4 first: increment to 1
* 1 2 4 first: reset to 0; middle: increment to 3
* 0 3 4 first: increment to 1
* 1 3 4 first: increment to 2
* 2 3 4 first: reset to 0; middle: reset to 1; last: increment to 5
* 0 1 5 first: reset to 0; middle: increment to 2
* 0 2 5 first: increment to 1
* 1 2 5 first: reset to 0; middle: increment to 3
* 0 3 5 first: increment to 1
* 1 3 5 first: increment to 2
* 2 3 5 first: reset to 0; middle: increment to 4
* 0 4 5 first: increment to 1
* 1 4 5 first: increment to 2
* 2 4 5 first: increment to 3
* 3 4 5 done
*
* This strategy works for dRAID but is less efficient when there are a large
* number of child vdevs and therefore permutations to check. Furthermore,
* since the raidz_map_t rows likely do not overlap, reconstruction would be
* possible as long as there are no more than nparity data errors per row.
* These additional permutations are not currently checked but could be as
* a future improvement.
*
* Returns 0 on success, ECKSUM on failure.
*/
static int
vdev_raidz_combrec(zio_t *zio)
{
int nparity = vdev_get_nparity(zio->io_vd);
raidz_map_t *rm = zio->io_vsd;
int physical_width = zio->io_vd->vdev_children;
int original_width = (rm->rm_original_width != 0) ?
rm->rm_original_width : physical_width;
for (int i = 0; i < rm->rm_nrows; i++) {
raidz_row_t *rr = rm->rm_row[i];
int total_errors = 0;
for (int c = 0; c < rr->rr_cols; c++) {
if (rr->rr_col[c].rc_error)
total_errors++;
}
if (total_errors > nparity)
return (vdev_raidz_worst_error(rr));
}
for (int num_failures = 1; num_failures <= nparity; num_failures++) {
int tstore[VDEV_RAIDZ_MAXPARITY + 2];
int *ltgts = &tstore[1]; /* value is logical child ID */
/*
* Determine number of logical children, n. See comment
* above raidz_simulate_failure().
*/
int n = 0;
for (int w = physical_width;
w >= original_width; w--) {
n += w;
}
ASSERT3U(num_failures, <=, nparity);
ASSERT3U(num_failures, <=, VDEV_RAIDZ_MAXPARITY);
/* Handle corner cases in combrec logic */
ltgts[-1] = -1;
for (int i = 0; i < num_failures; i++) {
ltgts[i] = i;
}
ltgts[num_failures] = n;
for (;;) {
int err = raidz_reconstruct(zio, ltgts, num_failures,
nparity);
if (err == EINVAL) {
/*
* Reconstruction not possible with this #
* failures; try more failures.
*/
break;
} else if (err == 0)
return (0);
/* Compute next targets to try */
for (int t = 0; ; t++) {
ASSERT3U(t, <, num_failures);
ltgts[t]++;
if (ltgts[t] == n) {
/* try more failures */
ASSERT3U(t, ==, num_failures - 1);
if (zfs_flags &
ZFS_DEBUG_RAIDZ_RECONSTRUCT) {
zfs_dbgmsg("reconstruction "
"failed for num_failures="
"%u; tried all "
"combinations",
num_failures);
}
break;
}
ASSERT3U(ltgts[t], <, n);
ASSERT3U(ltgts[t], <=, ltgts[t + 1]);
/*
* If that spot is available, we're done here.
* Try the next combination.
*/
if (ltgts[t] != ltgts[t + 1])
break; // found next combination
/*
* Otherwise, reset this tgt to the minimum,
* and move on to the next tgt.
*/
ltgts[t] = ltgts[t - 1] + 1;
ASSERT3U(ltgts[t], ==, t);
}
/* Increase the number of failures and keep trying. */
if (ltgts[num_failures - 1] == n)
break;
}
}
if (zfs_flags & ZFS_DEBUG_RAIDZ_RECONSTRUCT)
zfs_dbgmsg("reconstruction failed for all num_failures");
return (ECKSUM);
}
void
vdev_raidz_reconstruct(raidz_map_t *rm, const int *t, int nt)
{
for (uint64_t row = 0; row < rm->rm_nrows; row++) {
raidz_row_t *rr = rm->rm_row[row];
vdev_raidz_reconstruct_row(rm, rr, t, nt);
}
}
/*
* Complete a write IO operation on a RAIDZ VDev
*
* Outline:
* 1. Check for errors on the child IOs.
* 2. Return, setting an error code if too few child VDevs were written
* to reconstruct the data later. Note that partial writes are
* considered successful if they can be reconstructed at all.
*/
static void
vdev_raidz_io_done_write_impl(zio_t *zio, raidz_row_t *rr)
{
int normal_errors = 0;
int shadow_errors = 0;
ASSERT3U(rr->rr_missingparity, <=, rr->rr_firstdatacol);
ASSERT3U(rr->rr_missingdata, <=, rr->rr_cols - rr->rr_firstdatacol);
ASSERT3U(zio->io_type, ==, ZIO_TYPE_WRITE);
for (int c = 0; c < rr->rr_cols; c++) {
raidz_col_t *rc = &rr->rr_col[c];
if (rc->rc_error != 0) {
ASSERT(rc->rc_error != ECKSUM); /* child has no bp */
normal_errors++;
}
if (rc->rc_shadow_error != 0) {
ASSERT(rc->rc_shadow_error != ECKSUM);
shadow_errors++;
}
}
/*
* Treat partial writes as a success. If we couldn't write enough
* columns to reconstruct the data, the I/O failed. Otherwise, good
* enough. Note that in the case of a shadow write (during raidz
* expansion), depending on if we crash, either the normal (old) or
* shadow (new) location may become the "real" version of the block,
* so both locations must have sufficient redundancy.
*
* Now that we support write reallocation, it would be better
* to treat partial failure as real failure unless there are
* no non-degraded top-level vdevs left, and not update DTLs
* if we intend to reallocate.
*/
if (normal_errors > rr->rr_firstdatacol ||
shadow_errors > rr->rr_firstdatacol) {
zio->io_error = zio_worst_error(zio->io_error,
vdev_raidz_worst_error(rr));
}
}
static void
vdev_raidz_io_done_reconstruct_known_missing(zio_t *zio, raidz_map_t *rm,
raidz_row_t *rr)
{
int parity_errors = 0;
int parity_untried = 0;
int data_errors = 0;
int total_errors = 0;
ASSERT3U(rr->rr_missingparity, <=, rr->rr_firstdatacol);
ASSERT3U(rr->rr_missingdata, <=, rr->rr_cols - rr->rr_firstdatacol);
for (int c = 0; c < rr->rr_cols; c++) {
raidz_col_t *rc = &rr->rr_col[c];
/*
* If scrubbing and a replacing/sparing child vdev determined
* that not all of its children have an identical copy of the
* data, then clear the error so the column is treated like
* any other read and force a repair to correct the damage.
*/
if (rc->rc_error == ECKSUM) {
ASSERT(zio->io_flags & ZIO_FLAG_SCRUB);
vdev_raidz_checksum_error(zio, rc, rc->rc_abd);
rc->rc_force_repair = 1;
rc->rc_error = 0;
}
if (rc->rc_error) {
if (c < rr->rr_firstdatacol)
parity_errors++;
else
data_errors++;
total_errors++;
} else if (c < rr->rr_firstdatacol && !rc->rc_tried) {
parity_untried++;
}
}
/*
* If there were data errors and the number of errors we saw was
* correctable -- less than or equal to the number of parity disks read
* -- reconstruct based on the missing data.
*/
if (data_errors != 0 &&
total_errors <= rr->rr_firstdatacol - parity_untried) {
/*
* We either attempt to read all the parity columns or
* none of them. If we didn't try to read parity, we
* wouldn't be here in the correctable case. There must
* also have been fewer parity errors than parity
* columns or, again, we wouldn't be in this code path.
*/
ASSERT(parity_untried == 0);
ASSERT(parity_errors < rr->rr_firstdatacol);
/*
* Identify the data columns that reported an error.
*/
int n = 0;
int tgts[VDEV_RAIDZ_MAXPARITY];
for (int c = rr->rr_firstdatacol; c < rr->rr_cols; c++) {
raidz_col_t *rc = &rr->rr_col[c];
if (rc->rc_error != 0) {
ASSERT(n < VDEV_RAIDZ_MAXPARITY);
tgts[n++] = c;
}
}
ASSERT(rr->rr_firstdatacol >= n);
vdev_raidz_reconstruct_row(rm, rr, tgts, n);
}
}
/*
* Return the number of reads issued.
*/
static int
vdev_raidz_read_all(zio_t *zio, raidz_row_t *rr)
{
vdev_t *vd = zio->io_vd;
int nread = 0;
rr->rr_missingdata = 0;
rr->rr_missingparity = 0;
/*
* If this rows contains empty sectors which are not required
* for a normal read then allocate an ABD for them now so they
* may be read, verified, and any needed repairs performed.
*/
if (rr->rr_nempty != 0 && rr->rr_abd_empty == NULL)
vdev_draid_map_alloc_empty(zio, rr);
for (int c = 0; c < rr->rr_cols; c++) {
raidz_col_t *rc = &rr->rr_col[c];
if (rc->rc_tried || rc->rc_size == 0)
continue;
zio_nowait(zio_vdev_child_io(zio, NULL,
vd->vdev_child[rc->rc_devidx],
rc->rc_offset, rc->rc_abd, rc->rc_size,
zio->io_type, zio->io_priority, 0,
vdev_raidz_child_done, rc));
nread++;
}
return (nread);
}
/*
* We're here because either there were too many errors to even attempt
* reconstruction (total_errors == rm_first_datacol), or vdev_*_combrec()
* failed. In either case, there is enough bad data to prevent reconstruction.
* Start checksum ereports for all children which haven't failed.
*/
static void
vdev_raidz_io_done_unrecoverable(zio_t *zio)
{
raidz_map_t *rm = zio->io_vsd;
for (int i = 0; i < rm->rm_nrows; i++) {
raidz_row_t *rr = rm->rm_row[i];
for (int c = 0; c < rr->rr_cols; c++) {
raidz_col_t *rc = &rr->rr_col[c];
vdev_t *cvd = zio->io_vd->vdev_child[rc->rc_devidx];
if (rc->rc_error != 0)
continue;
zio_bad_cksum_t zbc;
zbc.zbc_has_cksum = 0;
zbc.zbc_injected = rm->rm_ecksuminjected;
mutex_enter(&cvd->vdev_stat_lock);
cvd->vdev_stat.vs_checksum_errors++;
mutex_exit(&cvd->vdev_stat_lock);
(void) zfs_ereport_start_checksum(zio->io_spa,
cvd, &zio->io_bookmark, zio, rc->rc_offset,
rc->rc_size, &zbc);
}
}
}
void
vdev_raidz_io_done(zio_t *zio)
{
raidz_map_t *rm = zio->io_vsd;
ASSERT(zio->io_bp != NULL);
if (zio->io_type == ZIO_TYPE_WRITE) {
for (int i = 0; i < rm->rm_nrows; i++) {
vdev_raidz_io_done_write_impl(zio, rm->rm_row[i]);
}
} else {
if (rm->rm_phys_col) {
/*
* This is an aggregated read. Copy the data and status
* from the aggregate abd's to the individual rows.
*/
for (int i = 0; i < rm->rm_nrows; i++) {
raidz_row_t *rr = rm->rm_row[i];
for (int c = 0; c < rr->rr_cols; c++) {
raidz_col_t *rc = &rr->rr_col[c];
if (rc->rc_tried || rc->rc_size == 0)
continue;
raidz_col_t *prc =
&rm->rm_phys_col[rc->rc_devidx];
rc->rc_error = prc->rc_error;
rc->rc_tried = prc->rc_tried;
rc->rc_skipped = prc->rc_skipped;
if (c >= rr->rr_firstdatacol) {
/*
* Note: this is slightly faster
* than using abd_copy_off().
*/
char *physbuf = abd_to_buf(
prc->rc_abd);
void *physloc = physbuf +
rc->rc_offset -
prc->rc_offset;
abd_copy_from_buf(rc->rc_abd,
physloc, rc->rc_size);
}
}
}
}
for (int i = 0; i < rm->rm_nrows; i++) {
raidz_row_t *rr = rm->rm_row[i];
vdev_raidz_io_done_reconstruct_known_missing(zio,
rm, rr);
}
if (raidz_checksum_verify(zio) == 0) {
for (int i = 0; i < rm->rm_nrows; i++) {
raidz_row_t *rr = rm->rm_row[i];
vdev_raidz_io_done_verified(zio, rr);
}
zio_checksum_verified(zio);
} else {
/*
* A sequential resilver has no checksum which makes
* combinatoral reconstruction impossible. This code
* path is unreachable since raidz_checksum_verify()
* has no checksum to verify and must succeed.
*/
ASSERT3U(zio->io_priority, !=, ZIO_PRIORITY_REBUILD);
/*
* This isn't a typical situation -- either we got a
* read error or a child silently returned bad data.
* Read every block so we can try again with as much
* data and parity as we can track down. If we've
* already been through once before, all children will
* be marked as tried so we'll proceed to combinatorial
* reconstruction.
*/
int nread = 0;
for (int i = 0; i < rm->rm_nrows; i++) {
nread += vdev_raidz_read_all(zio,
rm->rm_row[i]);
}
if (nread != 0) {
/*
* Normally our stage is VDEV_IO_DONE, but if
* we've already called redone(), it will have
* changed to VDEV_IO_START, in which case we
* don't want to call redone() again.
*/
if (zio->io_stage != ZIO_STAGE_VDEV_IO_START)
zio_vdev_io_redone(zio);
return;
}
/*
* It would be too expensive to try every possible
* combination of failed sectors in every row, so
* instead we try every combination of failed current or
* past physical disk. This means that if the incorrect
* sectors were all on Nparity disks at any point in the
* past, we will find the correct data. The only known
* case where this is less durable than a non-expanded
* RAIDZ, is if we have a silent failure during
* expansion. In that case, one block could be
* partially in the old format and partially in the
* new format, so we'd lost some sectors from the old
* format and some from the new format.
*
* e.g. logical_width=4 physical_width=6
* the 15 (6+5+4) possible failed disks are:
* width=6 child=0
* width=6 child=1
* width=6 child=2
* width=6 child=3
* width=6 child=4
* width=6 child=5
* width=5 child=0
* width=5 child=1
* width=5 child=2
* width=5 child=3
* width=5 child=4
* width=4 child=0
* width=4 child=1
* width=4 child=2
* width=4 child=3
* And we will try every combination of Nparity of these
* failing.
*
* As a first pass, we can generate every combo,
* and try reconstructing, ignoring any known
* failures. If any row has too many known + simulated
* failures, then we bail on reconstructing with this
* number of simulated failures. As an improvement,
* we could detect the number of whole known failures
* (i.e. we have known failures on these disks for
* every row; the disks never succeeded), and
* subtract that from the max # failures to simulate.
* We could go even further like the current
* combrec code, but that doesn't seem like it
* gains us very much. If we simulate a failure
* that is also a known failure, that's fine.
*/
zio->io_error = vdev_raidz_combrec(zio);
if (zio->io_error == ECKSUM &&
!(zio->io_flags & ZIO_FLAG_SPECULATIVE)) {
vdev_raidz_io_done_unrecoverable(zio);
}
}
}
if (rm->rm_lr != NULL) {
zfs_rangelock_exit(rm->rm_lr);
rm->rm_lr = NULL;
}
}
static void
vdev_raidz_state_change(vdev_t *vd, int faulted, int degraded)
{
vdev_raidz_t *vdrz = vd->vdev_tsd;
if (faulted > vdrz->vd_nparity)
vdev_set_state(vd, B_FALSE, VDEV_STATE_CANT_OPEN,
VDEV_AUX_NO_REPLICAS);
else if (degraded + faulted != 0)
vdev_set_state(vd, B_FALSE, VDEV_STATE_DEGRADED, VDEV_AUX_NONE);
else
vdev_set_state(vd, B_FALSE, VDEV_STATE_HEALTHY, VDEV_AUX_NONE);
}
/*
* Determine if any portion of the provided block resides on a child vdev
* with a dirty DTL and therefore needs to be resilvered. The function
* assumes that at least one DTL is dirty which implies that full stripe
* width blocks must be resilvered.
*/
static boolean_t
vdev_raidz_need_resilver(vdev_t *vd, const dva_t *dva, size_t psize,
uint64_t phys_birth)
{
vdev_raidz_t *vdrz = vd->vdev_tsd;
/*
* If we're in the middle of a RAIDZ expansion, this block may be in
* the old and/or new location. For simplicity, always resilver it.
*/
if (vdrz->vn_vre.vre_state == DSS_SCANNING)
return (B_TRUE);
uint64_t dcols = vd->vdev_children;
uint64_t nparity = vdrz->vd_nparity;
uint64_t ashift = vd->vdev_top->vdev_ashift;
/* The starting RAIDZ (parent) vdev sector of the block. */
uint64_t b = DVA_GET_OFFSET(dva) >> ashift;
/* The zio's size in units of the vdev's minimum sector size. */
uint64_t s = ((psize - 1) >> ashift) + 1;
/* The first column for this stripe. */
uint64_t f = b % dcols;
/* Unreachable by sequential resilver. */
ASSERT3U(phys_birth, !=, TXG_UNKNOWN);
if (!vdev_dtl_contains(vd, DTL_PARTIAL, phys_birth, 1))
return (B_FALSE);
if (s + nparity >= dcols)
return (B_TRUE);
for (uint64_t c = 0; c < s + nparity; c++) {
uint64_t devidx = (f + c) % dcols;
vdev_t *cvd = vd->vdev_child[devidx];
/*
* dsl_scan_need_resilver() already checked vd with
* vdev_dtl_contains(). So here just check cvd with
* vdev_dtl_empty(), cheaper and a good approximation.
*/
if (!vdev_dtl_empty(cvd, DTL_PARTIAL))
return (B_TRUE);
}
return (B_FALSE);
}
static void
vdev_raidz_xlate(vdev_t *cvd, const range_seg64_t *logical_rs,
range_seg64_t *physical_rs, range_seg64_t *remain_rs)
{
(void) remain_rs;
vdev_t *raidvd = cvd->vdev_parent;
ASSERT(raidvd->vdev_ops == &vdev_raidz_ops);
vdev_raidz_t *vdrz = raidvd->vdev_tsd;
if (vdrz->vn_vre.vre_state == DSS_SCANNING) {
/*
* We're in the middle of expansion, in which case the
* translation is in flux. Any answer we give may be wrong
* by the time we return, so it isn't safe for the caller to
* act on it. Therefore we say that this range isn't present
* on any children. The only consumers of this are "zpool
* initialize" and trimming, both of which are "best effort"
* anyway.
*/
physical_rs->rs_start = physical_rs->rs_end = 0;
remain_rs->rs_start = remain_rs->rs_end = 0;
return;
}
uint64_t width = vdrz->vd_physical_width;
uint64_t tgt_col = cvd->vdev_id;
uint64_t ashift = raidvd->vdev_top->vdev_ashift;
/* make sure the offsets are block-aligned */
ASSERT0(logical_rs->rs_start % (1 << ashift));
ASSERT0(logical_rs->rs_end % (1 << ashift));
uint64_t b_start = logical_rs->rs_start >> ashift;
uint64_t b_end = logical_rs->rs_end >> ashift;
uint64_t start_row = 0;
if (b_start > tgt_col) /* avoid underflow */
start_row = ((b_start - tgt_col - 1) / width) + 1;
uint64_t end_row = 0;
if (b_end > tgt_col)
end_row = ((b_end - tgt_col - 1) / width) + 1;
physical_rs->rs_start = start_row << ashift;
physical_rs->rs_end = end_row << ashift;
ASSERT3U(physical_rs->rs_start, <=, logical_rs->rs_start);
ASSERT3U(physical_rs->rs_end - physical_rs->rs_start, <=,
logical_rs->rs_end - logical_rs->rs_start);
}
static void
raidz_reflow_sync(void *arg, dmu_tx_t *tx)
{
spa_t *spa = arg;
int txgoff = dmu_tx_get_txg(tx) & TXG_MASK;
vdev_raidz_expand_t *vre = spa->spa_raidz_expand;
/*
* Ensure there are no i/os to the range that is being committed.
*/
uint64_t old_offset = RRSS_GET_OFFSET(&spa->spa_uberblock);
ASSERT3U(vre->vre_offset_pertxg[txgoff], >=, old_offset);
mutex_enter(&vre->vre_lock);
uint64_t new_offset =
MIN(vre->vre_offset_pertxg[txgoff], vre->vre_failed_offset);
/*
* We should not have committed anything that failed.
*/
VERIFY3U(vre->vre_failed_offset, >=, old_offset);
mutex_exit(&vre->vre_lock);
zfs_locked_range_t *lr = zfs_rangelock_enter(&vre->vre_rangelock,
old_offset, new_offset - old_offset,
RL_WRITER);
/*
* Update the uberblock that will be written when this txg completes.
*/
RAIDZ_REFLOW_SET(&spa->spa_uberblock,
RRSS_SCRATCH_INVALID_SYNCED_REFLOW, new_offset);
vre->vre_offset_pertxg[txgoff] = 0;
zfs_rangelock_exit(lr);
mutex_enter(&vre->vre_lock);
vre->vre_bytes_copied += vre->vre_bytes_copied_pertxg[txgoff];
vre->vre_bytes_copied_pertxg[txgoff] = 0;
mutex_exit(&vre->vre_lock);
vdev_t *vd = vdev_lookup_top(spa, vre->vre_vdev_id);
VERIFY0(zap_update(spa->spa_meta_objset,
vd->vdev_top_zap, VDEV_TOP_ZAP_RAIDZ_EXPAND_BYTES_COPIED,
sizeof (vre->vre_bytes_copied), 1, &vre->vre_bytes_copied, tx));
}
static void
raidz_reflow_complete_sync(void *arg, dmu_tx_t *tx)
{
spa_t *spa = arg;
vdev_raidz_expand_t *vre = spa->spa_raidz_expand;
vdev_t *raidvd = vdev_lookup_top(spa, vre->vre_vdev_id);
vdev_raidz_t *vdrz = raidvd->vdev_tsd;
for (int i = 0; i < TXG_SIZE; i++)
VERIFY0(vre->vre_offset_pertxg[i]);
reflow_node_t *re = kmem_zalloc(sizeof (*re), KM_SLEEP);
re->re_txg = tx->tx_txg + TXG_CONCURRENT_STATES;
re->re_logical_width = vdrz->vd_physical_width;
mutex_enter(&vdrz->vd_expand_lock);
avl_add(&vdrz->vd_expand_txgs, re);
mutex_exit(&vdrz->vd_expand_lock);
vdev_t *vd = vdev_lookup_top(spa, vre->vre_vdev_id);
/*
* Dirty the config so that the updated ZPOOL_CONFIG_RAIDZ_EXPAND_TXGS
* will get written (based on vd_expand_txgs).
*/
vdev_config_dirty(vd);
/*
* Before we change vre_state, the on-disk state must reflect that we
* have completed all copying, so that vdev_raidz_io_start() can use
* vre_state to determine if the reflow is in progress. See also the
* end of spa_raidz_expand_thread().
*/
VERIFY3U(RRSS_GET_OFFSET(&spa->spa_ubsync), ==,
raidvd->vdev_ms_count << raidvd->vdev_ms_shift);
vre->vre_end_time = gethrestime_sec();
vre->vre_state = DSS_FINISHED;
uint64_t state = vre->vre_state;
VERIFY0(zap_update(spa->spa_meta_objset,
vd->vdev_top_zap, VDEV_TOP_ZAP_RAIDZ_EXPAND_STATE,
sizeof (state), 1, &state, tx));
uint64_t end_time = vre->vre_end_time;
VERIFY0(zap_update(spa->spa_meta_objset,
vd->vdev_top_zap, VDEV_TOP_ZAP_RAIDZ_EXPAND_END_TIME,
sizeof (end_time), 1, &end_time, tx));
spa->spa_uberblock.ub_raidz_reflow_info = 0;
spa_history_log_internal(spa, "raidz vdev expansion completed", tx,
"%s vdev %llu new width %llu", spa_name(spa),
(unsigned long long)vd->vdev_id,
(unsigned long long)vd->vdev_children);
spa->spa_raidz_expand = NULL;
raidvd->vdev_rz_expanding = B_FALSE;
spa_async_request(spa, SPA_ASYNC_INITIALIZE_RESTART);
spa_async_request(spa, SPA_ASYNC_TRIM_RESTART);
spa_async_request(spa, SPA_ASYNC_AUTOTRIM_RESTART);
spa_notify_waiters(spa);
/*
* While we're in syncing context take the opportunity to
* setup a scrub. All the data has been sucessfully copied
* but we have not validated any checksums.
*/
pool_scan_func_t func = POOL_SCAN_SCRUB;
if (zfs_scrub_after_expand && dsl_scan_setup_check(&func, tx) == 0)
dsl_scan_setup_sync(&func, tx);
}
/*
* Struct for one copy zio.
*/
typedef struct raidz_reflow_arg {
vdev_raidz_expand_t *rra_vre;
zfs_locked_range_t *rra_lr;
uint64_t rra_txg;
} raidz_reflow_arg_t;
/*
* The write of the new location is done.
*/
static void
raidz_reflow_write_done(zio_t *zio)
{
raidz_reflow_arg_t *rra = zio->io_private;
vdev_raidz_expand_t *vre = rra->rra_vre;
abd_free(zio->io_abd);
mutex_enter(&vre->vre_lock);
if (zio->io_error != 0) {
/* Force a reflow pause on errors */
vre->vre_failed_offset =
MIN(vre->vre_failed_offset, rra->rra_lr->lr_offset);
}
ASSERT3U(vre->vre_outstanding_bytes, >=, zio->io_size);
vre->vre_outstanding_bytes -= zio->io_size;
if (rra->rra_lr->lr_offset + rra->rra_lr->lr_length <
vre->vre_failed_offset) {
vre->vre_bytes_copied_pertxg[rra->rra_txg & TXG_MASK] +=
zio->io_size;
}
cv_signal(&vre->vre_cv);
mutex_exit(&vre->vre_lock);
zfs_rangelock_exit(rra->rra_lr);
kmem_free(rra, sizeof (*rra));
spa_config_exit(zio->io_spa, SCL_STATE, zio->io_spa);
}
/*
* The read of the old location is done. The parent zio is the write to
* the new location. Allow it to start.
*/
static void
raidz_reflow_read_done(zio_t *zio)
{
raidz_reflow_arg_t *rra = zio->io_private;
vdev_raidz_expand_t *vre = rra->rra_vre;
/*
* If the read failed, or if it was done on a vdev that is not fully
* healthy (e.g. a child that has a resilver in progress), we may not
* have the correct data. Note that it's OK if the write proceeds.
* It may write garbage but the location is otherwise unused and we
* will retry later due to vre_failed_offset.
*/
if (zio->io_error != 0 || !vdev_dtl_empty(zio->io_vd, DTL_MISSING)) {
zfs_dbgmsg("reflow read failed off=%llu size=%llu txg=%llu "
"err=%u partial_dtl_empty=%u missing_dtl_empty=%u",
(long long)rra->rra_lr->lr_offset,
(long long)rra->rra_lr->lr_length,
(long long)rra->rra_txg,
zio->io_error,
vdev_dtl_empty(zio->io_vd, DTL_PARTIAL),
vdev_dtl_empty(zio->io_vd, DTL_MISSING));
mutex_enter(&vre->vre_lock);
/* Force a reflow pause on errors */
vre->vre_failed_offset =
MIN(vre->vre_failed_offset, rra->rra_lr->lr_offset);
mutex_exit(&vre->vre_lock);
}
zio_nowait(zio_unique_parent(zio));
}
static void
raidz_reflow_record_progress(vdev_raidz_expand_t *vre, uint64_t offset,
dmu_tx_t *tx)
{
int txgoff = dmu_tx_get_txg(tx) & TXG_MASK;
spa_t *spa = dmu_tx_pool(tx)->dp_spa;
if (offset == 0)
return;
mutex_enter(&vre->vre_lock);
ASSERT3U(vre->vre_offset, <=, offset);
vre->vre_offset = offset;
mutex_exit(&vre->vre_lock);
if (vre->vre_offset_pertxg[txgoff] == 0) {
dsl_sync_task_nowait(dmu_tx_pool(tx), raidz_reflow_sync,
spa, tx);
}
vre->vre_offset_pertxg[txgoff] = offset;
}
static boolean_t
vdev_raidz_expand_child_replacing(vdev_t *raidz_vd)
{
for (int i = 0; i < raidz_vd->vdev_children; i++) {
/* Quick check if a child is being replaced */
if (!raidz_vd->vdev_child[i]->vdev_ops->vdev_op_leaf)
return (B_TRUE);
}
return (B_FALSE);
}
static boolean_t
raidz_reflow_impl(vdev_t *vd, vdev_raidz_expand_t *vre, range_tree_t *rt,
dmu_tx_t *tx)
{
spa_t *spa = vd->vdev_spa;
int ashift = vd->vdev_top->vdev_ashift;
uint64_t offset, size;
if (!range_tree_find_in(rt, 0, vd->vdev_top->vdev_asize,
&offset, &size)) {
return (B_FALSE);
}
ASSERT(IS_P2ALIGNED(offset, 1 << ashift));
ASSERT3U(size, >=, 1 << ashift);
uint64_t length = 1 << ashift;
int txgoff = dmu_tx_get_txg(tx) & TXG_MASK;
uint64_t blkid = offset >> ashift;
int old_children = vd->vdev_children - 1;
/*
* We can only progress to the point that writes will not overlap
* with blocks whose progress has not yet been recorded on disk.
* Since partially-copied rows are still read from the old location,
* we need to stop one row before the sector-wise overlap, to prevent
* row-wise overlap.
*
* Note that even if we are skipping over a large unallocated region,
* we can't move the on-disk progress to `offset`, because concurrent
* writes/allocations could still use the currently-unallocated
* region.
*/
uint64_t ubsync_blkid =
RRSS_GET_OFFSET(&spa->spa_ubsync) >> ashift;
uint64_t next_overwrite_blkid = ubsync_blkid +
ubsync_blkid / old_children - old_children;
VERIFY3U(next_overwrite_blkid, >, ubsync_blkid);
if (blkid >= next_overwrite_blkid) {
raidz_reflow_record_progress(vre,
next_overwrite_blkid << ashift, tx);
return (B_TRUE);
}
range_tree_remove(rt, offset, length);
raidz_reflow_arg_t *rra = kmem_zalloc(sizeof (*rra), KM_SLEEP);
rra->rra_vre = vre;
rra->rra_lr = zfs_rangelock_enter(&vre->vre_rangelock,
offset, length, RL_WRITER);
rra->rra_txg = dmu_tx_get_txg(tx);
raidz_reflow_record_progress(vre, offset + length, tx);
mutex_enter(&vre->vre_lock);
vre->vre_outstanding_bytes += length;
mutex_exit(&vre->vre_lock);
/*
* SCL_STATE will be released when the read and write are done,
* by raidz_reflow_write_done().
*/
spa_config_enter(spa, SCL_STATE, spa, RW_READER);
/* check if a replacing vdev was added, if so treat it as an error */
if (vdev_raidz_expand_child_replacing(vd)) {
zfs_dbgmsg("replacing vdev encountered, reflow paused at "
"offset=%llu txg=%llu",
(long long)rra->rra_lr->lr_offset,
(long long)rra->rra_txg);
mutex_enter(&vre->vre_lock);
vre->vre_failed_offset =
MIN(vre->vre_failed_offset, rra->rra_lr->lr_offset);
cv_signal(&vre->vre_cv);
mutex_exit(&vre->vre_lock);
/* drop everything we acquired */
zfs_rangelock_exit(rra->rra_lr);
kmem_free(rra, sizeof (*rra));
spa_config_exit(spa, SCL_STATE, spa);
return (B_TRUE);
}
zio_t *pio = spa->spa_txg_zio[txgoff];
abd_t *abd = abd_alloc_for_io(length, B_FALSE);
zio_t *write_zio = zio_vdev_child_io(pio, NULL,
vd->vdev_child[blkid % vd->vdev_children],
(blkid / vd->vdev_children) << ashift,
abd, length,
ZIO_TYPE_WRITE, ZIO_PRIORITY_REMOVAL,
ZIO_FLAG_CANFAIL,
raidz_reflow_write_done, rra);
zio_nowait(zio_vdev_child_io(write_zio, NULL,
vd->vdev_child[blkid % old_children],
(blkid / old_children) << ashift,
abd, length,
ZIO_TYPE_READ, ZIO_PRIORITY_REMOVAL,
ZIO_FLAG_CANFAIL,
raidz_reflow_read_done, rra));
return (B_FALSE);
}
/*
* For testing (ztest specific)
*/
static void
raidz_expand_pause(uint_t pause_point)
{
while (raidz_expand_pause_point != 0 &&
raidz_expand_pause_point <= pause_point)
delay(hz);
}
static void
raidz_scratch_child_done(zio_t *zio)
{
zio_t *pio = zio->io_private;
mutex_enter(&pio->io_lock);
pio->io_error = zio_worst_error(pio->io_error, zio->io_error);
mutex_exit(&pio->io_lock);
}
/*
* Reflow the beginning portion of the vdev into an intermediate scratch area
* in memory and on disk. This operation must be persisted on disk before we
* proceed to overwrite the beginning portion with the reflowed data.
*
* This multi-step task can fail to complete if disk errors are encountered
* and we can return here after a pause (waiting for disk to become healthy).
*/
static void
raidz_reflow_scratch_sync(void *arg, dmu_tx_t *tx)
{
vdev_raidz_expand_t *vre = arg;
spa_t *spa = dmu_tx_pool(tx)->dp_spa;
zio_t *pio;
int error;
spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
vdev_t *raidvd = vdev_lookup_top(spa, vre->vre_vdev_id);
int ashift = raidvd->vdev_ashift;
uint64_t write_size = P2ALIGN_TYPED(VDEV_BOOT_SIZE, 1 << ashift,
uint64_t);
uint64_t logical_size = write_size * raidvd->vdev_children;
uint64_t read_size =
P2ROUNDUP(DIV_ROUND_UP(logical_size, (raidvd->vdev_children - 1)),
1 << ashift);
/*
* The scratch space must be large enough to get us to the point
* that one row does not overlap itself when moved. This is checked
* by vdev_raidz_attach_check().
*/
VERIFY3U(write_size, >=, raidvd->vdev_children << ashift);
VERIFY3U(write_size, <=, VDEV_BOOT_SIZE);
VERIFY3U(write_size, <=, read_size);
zfs_locked_range_t *lr = zfs_rangelock_enter(&vre->vre_rangelock,
0, logical_size, RL_WRITER);
abd_t **abds = kmem_alloc(raidvd->vdev_children * sizeof (abd_t *),
KM_SLEEP);
for (int i = 0; i < raidvd->vdev_children; i++) {
abds[i] = abd_alloc_linear(read_size, B_FALSE);
}
raidz_expand_pause(RAIDZ_EXPAND_PAUSE_PRE_SCRATCH_1);
/*
* If we have already written the scratch area then we must read from
* there, since new writes were redirected there while we were paused
* or the original location may have been partially overwritten with
* reflowed data.
*/
if (RRSS_GET_STATE(&spa->spa_ubsync) == RRSS_SCRATCH_VALID) {
VERIFY3U(RRSS_GET_OFFSET(&spa->spa_ubsync), ==, logical_size);
/*
* Read from scratch space.
*/
pio = zio_root(spa, NULL, NULL, ZIO_FLAG_CANFAIL);
for (int i = 0; i < raidvd->vdev_children; i++) {
/*
* Note: zio_vdev_child_io() adds VDEV_LABEL_START_SIZE
* to the offset to calculate the physical offset to
* write to. Passing in a negative offset makes us
* access the scratch area.
*/
zio_nowait(zio_vdev_child_io(pio, NULL,
raidvd->vdev_child[i],
VDEV_BOOT_OFFSET - VDEV_LABEL_START_SIZE, abds[i],
write_size, ZIO_TYPE_READ, ZIO_PRIORITY_ASYNC_READ,
ZIO_FLAG_CANFAIL, raidz_scratch_child_done, pio));
}
error = zio_wait(pio);
if (error != 0) {
zfs_dbgmsg("reflow: error %d reading scratch location",
error);
goto io_error_exit;
}
goto overwrite;
}
/*
* Read from original location.
*/
pio = zio_root(spa, NULL, NULL, ZIO_FLAG_CANFAIL);
for (int i = 0; i < raidvd->vdev_children - 1; i++) {
ASSERT0(vdev_is_dead(raidvd->vdev_child[i]));
zio_nowait(zio_vdev_child_io(pio, NULL, raidvd->vdev_child[i],
0, abds[i], read_size, ZIO_TYPE_READ,
ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_CANFAIL,
raidz_scratch_child_done, pio));
}
error = zio_wait(pio);
if (error != 0) {
zfs_dbgmsg("reflow: error %d reading original location", error);
io_error_exit:
for (int i = 0; i < raidvd->vdev_children; i++)
abd_free(abds[i]);
kmem_free(abds, raidvd->vdev_children * sizeof (abd_t *));
zfs_rangelock_exit(lr);
spa_config_exit(spa, SCL_STATE, FTAG);
return;
}
raidz_expand_pause(RAIDZ_EXPAND_PAUSE_PRE_SCRATCH_2);
/*
* Reflow in memory.
*/
uint64_t logical_sectors = logical_size >> ashift;
for (int i = raidvd->vdev_children - 1; i < logical_sectors; i++) {
int oldchild = i % (raidvd->vdev_children - 1);
uint64_t oldoff = (i / (raidvd->vdev_children - 1)) << ashift;
int newchild = i % raidvd->vdev_children;
uint64_t newoff = (i / raidvd->vdev_children) << ashift;
/* a single sector should not be copying over itself */
ASSERT(!(newchild == oldchild && newoff == oldoff));
abd_copy_off(abds[newchild], abds[oldchild],
newoff, oldoff, 1 << ashift);
}
/*
* Verify that we filled in everything we intended to (write_size on
* each child).
*/
VERIFY0(logical_sectors % raidvd->vdev_children);
VERIFY3U((logical_sectors / raidvd->vdev_children) << ashift, ==,
write_size);
/*
* Write to scratch location (boot area).
*/
pio = zio_root(spa, NULL, NULL, ZIO_FLAG_CANFAIL);
for (int i = 0; i < raidvd->vdev_children; i++) {
/*
* Note: zio_vdev_child_io() adds VDEV_LABEL_START_SIZE to
* the offset to calculate the physical offset to write to.
* Passing in a negative offset lets us access the boot area.
*/
zio_nowait(zio_vdev_child_io(pio, NULL, raidvd->vdev_child[i],
VDEV_BOOT_OFFSET - VDEV_LABEL_START_SIZE, abds[i],
write_size, ZIO_TYPE_WRITE, ZIO_PRIORITY_ASYNC_WRITE,
ZIO_FLAG_CANFAIL, raidz_scratch_child_done, pio));
}
error = zio_wait(pio);
if (error != 0) {
zfs_dbgmsg("reflow: error %d writing scratch location", error);
goto io_error_exit;
}
pio = zio_root(spa, NULL, NULL, 0);
zio_flush(pio, raidvd);
zio_wait(pio);
zfs_dbgmsg("reflow: wrote %llu bytes (logical) to scratch area",
(long long)logical_size);
raidz_expand_pause(RAIDZ_EXPAND_PAUSE_PRE_SCRATCH_3);
/*
* Update uberblock to indicate that scratch space is valid. This is
* needed because after this point, the real location may be
* overwritten. If we crash, we need to get the data from the
* scratch space, rather than the real location.
*
* Note: ub_timestamp is bumped so that vdev_uberblock_compare()
* will prefer this uberblock.
*/
RAIDZ_REFLOW_SET(&spa->spa_ubsync, RRSS_SCRATCH_VALID, logical_size);
spa->spa_ubsync.ub_timestamp++;
ASSERT0(vdev_uberblock_sync_list(&spa->spa_root_vdev, 1,
&spa->spa_ubsync, ZIO_FLAG_CONFIG_WRITER));
if (spa_multihost(spa))
mmp_update_uberblock(spa, &spa->spa_ubsync);
zfs_dbgmsg("reflow: uberblock updated "
"(txg %llu, SCRATCH_VALID, size %llu, ts %llu)",
(long long)spa->spa_ubsync.ub_txg,
(long long)logical_size,
(long long)spa->spa_ubsync.ub_timestamp);
raidz_expand_pause(RAIDZ_EXPAND_PAUSE_SCRATCH_VALID);
/*
* Overwrite with reflow'ed data.
*/
overwrite:
pio = zio_root(spa, NULL, NULL, ZIO_FLAG_CANFAIL);
for (int i = 0; i < raidvd->vdev_children; i++) {
zio_nowait(zio_vdev_child_io(pio, NULL, raidvd->vdev_child[i],
0, abds[i], write_size, ZIO_TYPE_WRITE,
ZIO_PRIORITY_ASYNC_WRITE, ZIO_FLAG_CANFAIL,
raidz_scratch_child_done, pio));
}
error = zio_wait(pio);
if (error != 0) {
/*
* When we exit early here and drop the range lock, new
* writes will go into the scratch area so we'll need to
* read from there when we return after pausing.
*/
zfs_dbgmsg("reflow: error %d writing real location", error);
/*
* Update the uberblock that is written when this txg completes.
*/
RAIDZ_REFLOW_SET(&spa->spa_uberblock, RRSS_SCRATCH_VALID,
logical_size);
goto io_error_exit;
}
pio = zio_root(spa, NULL, NULL, 0);
zio_flush(pio, raidvd);
zio_wait(pio);
zfs_dbgmsg("reflow: overwrote %llu bytes (logical) to real location",
(long long)logical_size);
for (int i = 0; i < raidvd->vdev_children; i++)
abd_free(abds[i]);
kmem_free(abds, raidvd->vdev_children * sizeof (abd_t *));
raidz_expand_pause(RAIDZ_EXPAND_PAUSE_SCRATCH_REFLOWED);
/*
* Update uberblock to indicate that the initial part has been
* reflow'ed. This is needed because after this point (when we exit
* the rangelock), we allow regular writes to this region, which will
* be written to the new location only (because reflow_offset_next ==
* reflow_offset_synced). If we crashed and re-copied from the
* scratch space, we would lose the regular writes.
*/
RAIDZ_REFLOW_SET(&spa->spa_ubsync, RRSS_SCRATCH_INVALID_SYNCED,
logical_size);
spa->spa_ubsync.ub_timestamp++;
ASSERT0(vdev_uberblock_sync_list(&spa->spa_root_vdev, 1,
&spa->spa_ubsync, ZIO_FLAG_CONFIG_WRITER));
if (spa_multihost(spa))
mmp_update_uberblock(spa, &spa->spa_ubsync);
zfs_dbgmsg("reflow: uberblock updated "
"(txg %llu, SCRATCH_NOT_IN_USE, size %llu, ts %llu)",
(long long)spa->spa_ubsync.ub_txg,
(long long)logical_size,
(long long)spa->spa_ubsync.ub_timestamp);
raidz_expand_pause(RAIDZ_EXPAND_PAUSE_SCRATCH_POST_REFLOW_1);
/*
* Update progress.
*/
vre->vre_offset = logical_size;
zfs_rangelock_exit(lr);
spa_config_exit(spa, SCL_STATE, FTAG);
int txgoff = dmu_tx_get_txg(tx) & TXG_MASK;
vre->vre_offset_pertxg[txgoff] = vre->vre_offset;
vre->vre_bytes_copied_pertxg[txgoff] = vre->vre_bytes_copied;
/*
* Note - raidz_reflow_sync() will update the uberblock state to
* RRSS_SCRATCH_INVALID_SYNCED_REFLOW
*/
raidz_reflow_sync(spa, tx);
raidz_expand_pause(RAIDZ_EXPAND_PAUSE_SCRATCH_POST_REFLOW_2);
}
/*
* We crashed in the middle of raidz_reflow_scratch_sync(); complete its work
* here. No other i/o can be in progress, so we don't need the vre_rangelock.
*/
void
vdev_raidz_reflow_copy_scratch(spa_t *spa)
{
vdev_raidz_expand_t *vre = spa->spa_raidz_expand;
uint64_t logical_size = RRSS_GET_OFFSET(&spa->spa_uberblock);
ASSERT3U(RRSS_GET_STATE(&spa->spa_uberblock), ==, RRSS_SCRATCH_VALID);
spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
vdev_t *raidvd = vdev_lookup_top(spa, vre->vre_vdev_id);
ASSERT0(logical_size % raidvd->vdev_children);
uint64_t write_size = logical_size / raidvd->vdev_children;
zio_t *pio;
/*
* Read from scratch space.
*/
abd_t **abds = kmem_alloc(raidvd->vdev_children * sizeof (abd_t *),
KM_SLEEP);
for (int i = 0; i < raidvd->vdev_children; i++) {
abds[i] = abd_alloc_linear(write_size, B_FALSE);
}
pio = zio_root(spa, NULL, NULL, 0);
for (int i = 0; i < raidvd->vdev_children; i++) {
/*
* Note: zio_vdev_child_io() adds VDEV_LABEL_START_SIZE to
* the offset to calculate the physical offset to write to.
* Passing in a negative offset lets us access the boot area.
*/
zio_nowait(zio_vdev_child_io(pio, NULL, raidvd->vdev_child[i],
VDEV_BOOT_OFFSET - VDEV_LABEL_START_SIZE, abds[i],
write_size, ZIO_TYPE_READ,
ZIO_PRIORITY_ASYNC_READ, 0,
raidz_scratch_child_done, pio));
}
zio_wait(pio);
/*
* Overwrite real location with reflow'ed data.
*/
pio = zio_root(spa, NULL, NULL, 0);
for (int i = 0; i < raidvd->vdev_children; i++) {
zio_nowait(zio_vdev_child_io(pio, NULL, raidvd->vdev_child[i],
0, abds[i], write_size, ZIO_TYPE_WRITE,
ZIO_PRIORITY_ASYNC_WRITE, 0,
raidz_scratch_child_done, pio));
}
zio_wait(pio);
pio = zio_root(spa, NULL, NULL, 0);
zio_flush(pio, raidvd);
zio_wait(pio);
zfs_dbgmsg("reflow recovery: overwrote %llu bytes (logical) "
"to real location", (long long)logical_size);
for (int i = 0; i < raidvd->vdev_children; i++)
abd_free(abds[i]);
kmem_free(abds, raidvd->vdev_children * sizeof (abd_t *));
/*
* Update uberblock.
*/
RAIDZ_REFLOW_SET(&spa->spa_ubsync,
RRSS_SCRATCH_INVALID_SYNCED_ON_IMPORT, logical_size);
spa->spa_ubsync.ub_timestamp++;
VERIFY0(vdev_uberblock_sync_list(&spa->spa_root_vdev, 1,
&spa->spa_ubsync, ZIO_FLAG_CONFIG_WRITER));
if (spa_multihost(spa))
mmp_update_uberblock(spa, &spa->spa_ubsync);
zfs_dbgmsg("reflow recovery: uberblock updated "
"(txg %llu, SCRATCH_NOT_IN_USE, size %llu, ts %llu)",
(long long)spa->spa_ubsync.ub_txg,
(long long)logical_size,
(long long)spa->spa_ubsync.ub_timestamp);
dmu_tx_t *tx = dmu_tx_create_assigned(spa->spa_dsl_pool,
spa_first_txg(spa));
int txgoff = dmu_tx_get_txg(tx) & TXG_MASK;
vre->vre_offset = logical_size;
vre->vre_offset_pertxg[txgoff] = vre->vre_offset;
vre->vre_bytes_copied_pertxg[txgoff] = vre->vre_bytes_copied;
/*
* Note that raidz_reflow_sync() will update the uberblock once more
*/
raidz_reflow_sync(spa, tx);
dmu_tx_commit(tx);
spa_config_exit(spa, SCL_STATE, FTAG);
}
static boolean_t
spa_raidz_expand_thread_check(void *arg, zthr_t *zthr)
{
(void) zthr;
spa_t *spa = arg;
return (spa->spa_raidz_expand != NULL &&
!spa->spa_raidz_expand->vre_waiting_for_resilver);
}
/*
* RAIDZ expansion background thread
*
* Can be called multiple times if the reflow is paused
*/
static void
spa_raidz_expand_thread(void *arg, zthr_t *zthr)
{
spa_t *spa = arg;
vdev_raidz_expand_t *vre = spa->spa_raidz_expand;
if (RRSS_GET_STATE(&spa->spa_ubsync) == RRSS_SCRATCH_VALID)
vre->vre_offset = 0;
else
vre->vre_offset = RRSS_GET_OFFSET(&spa->spa_ubsync);
/* Reflow the begining portion using the scratch area */
if (vre->vre_offset == 0) {
VERIFY0(dsl_sync_task(spa_name(spa),
NULL, raidz_reflow_scratch_sync,
vre, 0, ZFS_SPACE_CHECK_NONE));
/* if we encountered errors then pause */
if (vre->vre_offset == 0) {
mutex_enter(&vre->vre_lock);
vre->vre_waiting_for_resilver = B_TRUE;
mutex_exit(&vre->vre_lock);
return;
}
}
spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
vdev_t *raidvd = vdev_lookup_top(spa, vre->vre_vdev_id);
uint64_t guid = raidvd->vdev_guid;
/* Iterate over all the remaining metaslabs */
for (uint64_t i = vre->vre_offset >> raidvd->vdev_ms_shift;
i < raidvd->vdev_ms_count &&
!zthr_iscancelled(zthr) &&
vre->vre_failed_offset == UINT64_MAX; i++) {
metaslab_t *msp = raidvd->vdev_ms[i];
metaslab_disable(msp);
mutex_enter(&msp->ms_lock);
/*
* The metaslab may be newly created (for the expanded
* space), in which case its trees won't exist yet,
* so we need to bail out early.
*/
if (msp->ms_new) {
mutex_exit(&msp->ms_lock);
metaslab_enable(msp, B_FALSE, B_FALSE);
continue;
}
VERIFY0(metaslab_load(msp));
/*
* We want to copy everything except the free (allocatable)
* space. Note that there may be a little bit more free
* space (e.g. in ms_defer), and it's fine to copy that too.
*/
range_tree_t *rt = range_tree_create(NULL, RANGE_SEG64,
NULL, 0, 0);
range_tree_add(rt, msp->ms_start, msp->ms_size);
range_tree_walk(msp->ms_allocatable, range_tree_remove, rt);
mutex_exit(&msp->ms_lock);
/*
* Force the last sector of each metaslab to be copied. This
* ensures that we advance the on-disk progress to the end of
* this metaslab while the metaslab is disabled. Otherwise, we
* could move past this metaslab without advancing the on-disk
* progress, and then an allocation to this metaslab would not
* be copied.
*/
int sectorsz = 1 << raidvd->vdev_ashift;
uint64_t ms_last_offset = msp->ms_start +
msp->ms_size - sectorsz;
if (!range_tree_contains(rt, ms_last_offset, sectorsz)) {
range_tree_add(rt, ms_last_offset, sectorsz);
}
/*
* When we are resuming from a paused expansion (i.e.
* when importing a pool with a expansion in progress),
* discard any state that we have already processed.
*/
range_tree_clear(rt, 0, vre->vre_offset);
while (!zthr_iscancelled(zthr) &&
!range_tree_is_empty(rt) &&
vre->vre_failed_offset == UINT64_MAX) {
/*
* We need to periodically drop the config lock so that
* writers can get in. Additionally, we can't wait
* for a txg to sync while holding a config lock
* (since a waiting writer could cause a 3-way deadlock
* with the sync thread, which also gets a config
* lock for reader). So we can't hold the config lock
* while calling dmu_tx_assign().
*/
spa_config_exit(spa, SCL_CONFIG, FTAG);
/*
* If requested, pause the reflow when the amount
* specified by raidz_expand_max_reflow_bytes is reached
*
* This pause is only used during testing or debugging.
*/
while (raidz_expand_max_reflow_bytes != 0 &&
raidz_expand_max_reflow_bytes <=
vre->vre_bytes_copied && !zthr_iscancelled(zthr)) {
delay(hz);
}
mutex_enter(&vre->vre_lock);
while (vre->vre_outstanding_bytes >
raidz_expand_max_copy_bytes) {
cv_wait(&vre->vre_cv, &vre->vre_lock);
}
mutex_exit(&vre->vre_lock);
dmu_tx_t *tx =
dmu_tx_create_dd(spa_get_dsl(spa)->dp_mos_dir);
VERIFY0(dmu_tx_assign(tx, TXG_WAIT));
uint64_t txg = dmu_tx_get_txg(tx);
/*
* Reacquire the vdev_config lock. Theoretically, the
* vdev_t that we're expanding may have changed.
*/
spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
raidvd = vdev_lookup_top(spa, vre->vre_vdev_id);
boolean_t needsync =
raidz_reflow_impl(raidvd, vre, rt, tx);
dmu_tx_commit(tx);
if (needsync) {
spa_config_exit(spa, SCL_CONFIG, FTAG);
txg_wait_synced(spa->spa_dsl_pool, txg);
spa_config_enter(spa, SCL_CONFIG, FTAG,
RW_READER);
}
}
spa_config_exit(spa, SCL_CONFIG, FTAG);
metaslab_enable(msp, B_FALSE, B_FALSE);
range_tree_vacate(rt, NULL, NULL);
range_tree_destroy(rt);
spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
raidvd = vdev_lookup_top(spa, vre->vre_vdev_id);
}
spa_config_exit(spa, SCL_CONFIG, FTAG);
/*
* The txg_wait_synced() here ensures that all reflow zio's have
* completed, and vre_failed_offset has been set if necessary. It
* also ensures that the progress of the last raidz_reflow_sync() is
* written to disk before raidz_reflow_complete_sync() changes the
* in-memory vre_state. vdev_raidz_io_start() uses vre_state to
* determine if a reflow is in progress, in which case we may need to
* write to both old and new locations. Therefore we can only change
* vre_state once this is not necessary, which is once the on-disk
* progress (in spa_ubsync) has been set past any possible writes (to
* the end of the last metaslab).
*/
txg_wait_synced(spa->spa_dsl_pool, 0);
if (!zthr_iscancelled(zthr) &&
vre->vre_offset == raidvd->vdev_ms_count << raidvd->vdev_ms_shift) {
/*
* We are not being canceled or paused, so the reflow must be
* complete. In that case also mark it as completed on disk.
*/
ASSERT3U(vre->vre_failed_offset, ==, UINT64_MAX);
VERIFY0(dsl_sync_task(spa_name(spa), NULL,
raidz_reflow_complete_sync, spa,
0, ZFS_SPACE_CHECK_NONE));
(void) vdev_online(spa, guid, ZFS_ONLINE_EXPAND, NULL);
} else {
/*
* Wait for all copy zio's to complete and for all the
* raidz_reflow_sync() synctasks to be run.
*/
spa_history_log_internal(spa, "reflow pause",
NULL, "offset=%llu failed_offset=%lld",
(long long)vre->vre_offset,
(long long)vre->vre_failed_offset);
mutex_enter(&vre->vre_lock);
if (vre->vre_failed_offset != UINT64_MAX) {
/*
* Reset progress so that we will retry everything
* after the point that something failed.
*/
vre->vre_offset = vre->vre_failed_offset;
vre->vre_failed_offset = UINT64_MAX;
vre->vre_waiting_for_resilver = B_TRUE;
}
mutex_exit(&vre->vre_lock);
}
}
void
spa_start_raidz_expansion_thread(spa_t *spa)
{
ASSERT3P(spa->spa_raidz_expand_zthr, ==, NULL);
spa->spa_raidz_expand_zthr = zthr_create("raidz_expand",
spa_raidz_expand_thread_check, spa_raidz_expand_thread,
spa, defclsyspri);
}
void
raidz_dtl_reassessed(vdev_t *vd)
{
spa_t *spa = vd->vdev_spa;
if (spa->spa_raidz_expand != NULL) {
vdev_raidz_expand_t *vre = spa->spa_raidz_expand;
/*
* we get called often from vdev_dtl_reassess() so make
* sure it's our vdev and any replacing is complete
*/
if (vd->vdev_top->vdev_id == vre->vre_vdev_id &&
!vdev_raidz_expand_child_replacing(vd->vdev_top)) {
mutex_enter(&vre->vre_lock);
if (vre->vre_waiting_for_resilver) {
vdev_dbgmsg(vd, "DTL reassessed, "
"continuing raidz expansion");
vre->vre_waiting_for_resilver = B_FALSE;
zthr_wakeup(spa->spa_raidz_expand_zthr);
}
mutex_exit(&vre->vre_lock);
}
}
}
int
vdev_raidz_attach_check(vdev_t *new_child)
{
vdev_t *raidvd = new_child->vdev_parent;
uint64_t new_children = raidvd->vdev_children;
/*
* We use the "boot" space as scratch space to handle overwriting the
* initial part of the vdev. If it is too small, then this expansion
* is not allowed. This would be very unusual (e.g. ashift > 13 and
* >200 children).
*/
if (new_children << raidvd->vdev_ashift > VDEV_BOOT_SIZE) {
return (EINVAL);
}
return (0);
}
void
vdev_raidz_attach_sync(void *arg, dmu_tx_t *tx)
{
vdev_t *new_child = arg;
spa_t *spa = new_child->vdev_spa;
vdev_t *raidvd = new_child->vdev_parent;
vdev_raidz_t *vdrz = raidvd->vdev_tsd;
ASSERT3P(raidvd->vdev_ops, ==, &vdev_raidz_ops);
ASSERT3P(raidvd->vdev_top, ==, raidvd);
ASSERT3U(raidvd->vdev_children, >, vdrz->vd_original_width);
ASSERT3U(raidvd->vdev_children, ==, vdrz->vd_physical_width + 1);
ASSERT3P(raidvd->vdev_child[raidvd->vdev_children - 1], ==,
new_child);
spa_feature_incr(spa, SPA_FEATURE_RAIDZ_EXPANSION, tx);
vdrz->vd_physical_width++;
VERIFY0(spa->spa_uberblock.ub_raidz_reflow_info);
vdrz->vn_vre.vre_vdev_id = raidvd->vdev_id;
vdrz->vn_vre.vre_offset = 0;
vdrz->vn_vre.vre_failed_offset = UINT64_MAX;
spa->spa_raidz_expand = &vdrz->vn_vre;
zthr_wakeup(spa->spa_raidz_expand_zthr);
/*
* Dirty the config so that ZPOOL_CONFIG_RAIDZ_EXPANDING will get
* written to the config.
*/
vdev_config_dirty(raidvd);
vdrz->vn_vre.vre_start_time = gethrestime_sec();
vdrz->vn_vre.vre_end_time = 0;
vdrz->vn_vre.vre_state = DSS_SCANNING;
vdrz->vn_vre.vre_bytes_copied = 0;
uint64_t state = vdrz->vn_vre.vre_state;
VERIFY0(zap_update(spa->spa_meta_objset,
raidvd->vdev_top_zap, VDEV_TOP_ZAP_RAIDZ_EXPAND_STATE,
sizeof (state), 1, &state, tx));
uint64_t start_time = vdrz->vn_vre.vre_start_time;
VERIFY0(zap_update(spa->spa_meta_objset,
raidvd->vdev_top_zap, VDEV_TOP_ZAP_RAIDZ_EXPAND_START_TIME,
sizeof (start_time), 1, &start_time, tx));
(void) zap_remove(spa->spa_meta_objset,
raidvd->vdev_top_zap, VDEV_TOP_ZAP_RAIDZ_EXPAND_END_TIME, tx);
(void) zap_remove(spa->spa_meta_objset,
raidvd->vdev_top_zap, VDEV_TOP_ZAP_RAIDZ_EXPAND_BYTES_COPIED, tx);
spa_history_log_internal(spa, "raidz vdev expansion started", tx,
"%s vdev %llu new width %llu", spa_name(spa),
(unsigned long long)raidvd->vdev_id,
(unsigned long long)raidvd->vdev_children);
}
int
vdev_raidz_load(vdev_t *vd)
{
vdev_raidz_t *vdrz = vd->vdev_tsd;
int err;
uint64_t state = DSS_NONE;
uint64_t start_time = 0;
uint64_t end_time = 0;
uint64_t bytes_copied = 0;
if (vd->vdev_top_zap != 0) {
err = zap_lookup(vd->vdev_spa->spa_meta_objset,
vd->vdev_top_zap, VDEV_TOP_ZAP_RAIDZ_EXPAND_STATE,
sizeof (state), 1, &state);
if (err != 0 && err != ENOENT)
return (err);
err = zap_lookup(vd->vdev_spa->spa_meta_objset,
vd->vdev_top_zap, VDEV_TOP_ZAP_RAIDZ_EXPAND_START_TIME,
sizeof (start_time), 1, &start_time);
if (err != 0 && err != ENOENT)
return (err);
err = zap_lookup(vd->vdev_spa->spa_meta_objset,
vd->vdev_top_zap, VDEV_TOP_ZAP_RAIDZ_EXPAND_END_TIME,
sizeof (end_time), 1, &end_time);
if (err != 0 && err != ENOENT)
return (err);
err = zap_lookup(vd->vdev_spa->spa_meta_objset,
vd->vdev_top_zap, VDEV_TOP_ZAP_RAIDZ_EXPAND_BYTES_COPIED,
sizeof (bytes_copied), 1, &bytes_copied);
if (err != 0 && err != ENOENT)
return (err);
}
/*
* If we are in the middle of expansion, vre_state should have
* already been set by vdev_raidz_init().
*/
EQUIV(vdrz->vn_vre.vre_state == DSS_SCANNING, state == DSS_SCANNING);
vdrz->vn_vre.vre_state = (dsl_scan_state_t)state;
vdrz->vn_vre.vre_start_time = start_time;
vdrz->vn_vre.vre_end_time = end_time;
vdrz->vn_vre.vre_bytes_copied = bytes_copied;
return (0);
}
int
spa_raidz_expand_get_stats(spa_t *spa, pool_raidz_expand_stat_t *pres)
{
vdev_raidz_expand_t *vre = spa->spa_raidz_expand;
if (vre == NULL) {
/* no removal in progress; find most recent completed */
for (int c = 0; c < spa->spa_root_vdev->vdev_children; c++) {
vdev_t *vd = spa->spa_root_vdev->vdev_child[c];
if (vd->vdev_ops == &vdev_raidz_ops) {
vdev_raidz_t *vdrz = vd->vdev_tsd;
if (vdrz->vn_vre.vre_end_time != 0 &&
(vre == NULL ||
vdrz->vn_vre.vre_end_time >
vre->vre_end_time)) {
vre = &vdrz->vn_vre;
}
}
}
}
if (vre == NULL) {
return (SET_ERROR(ENOENT));
}
pres->pres_state = vre->vre_state;
pres->pres_expanding_vdev = vre->vre_vdev_id;
vdev_t *vd = vdev_lookup_top(spa, vre->vre_vdev_id);
pres->pres_to_reflow = vd->vdev_stat.vs_alloc;
mutex_enter(&vre->vre_lock);
pres->pres_reflowed = vre->vre_bytes_copied;
for (int i = 0; i < TXG_SIZE; i++)
pres->pres_reflowed += vre->vre_bytes_copied_pertxg[i];
mutex_exit(&vre->vre_lock);
pres->pres_start_time = vre->vre_start_time;
pres->pres_end_time = vre->vre_end_time;
pres->pres_waiting_for_resilver = vre->vre_waiting_for_resilver;
return (0);
}
/*
* Initialize private RAIDZ specific fields from the nvlist.
*/
static int
vdev_raidz_init(spa_t *spa, nvlist_t *nv, void **tsd)
{
uint_t children;
nvlist_t **child;
int error = nvlist_lookup_nvlist_array(nv,
ZPOOL_CONFIG_CHILDREN, &child, &children);
if (error != 0)
return (SET_ERROR(EINVAL));
uint64_t nparity;
if (nvlist_lookup_uint64(nv, ZPOOL_CONFIG_NPARITY, &nparity) == 0) {
if (nparity == 0 || nparity > VDEV_RAIDZ_MAXPARITY)
return (SET_ERROR(EINVAL));
/*
* Previous versions could only support 1 or 2 parity
* device.
*/
if (nparity > 1 && spa_version(spa) < SPA_VERSION_RAIDZ2)
return (SET_ERROR(EINVAL));
else if (nparity > 2 && spa_version(spa) < SPA_VERSION_RAIDZ3)
return (SET_ERROR(EINVAL));
} else {
/*
* We require the parity to be specified for SPAs that
* support multiple parity levels.
*/
if (spa_version(spa) >= SPA_VERSION_RAIDZ2)
return (SET_ERROR(EINVAL));
/*
* Otherwise, we default to 1 parity device for RAID-Z.
*/
nparity = 1;
}
vdev_raidz_t *vdrz = kmem_zalloc(sizeof (*vdrz), KM_SLEEP);
vdrz->vn_vre.vre_vdev_id = -1;
vdrz->vn_vre.vre_offset = UINT64_MAX;
vdrz->vn_vre.vre_failed_offset = UINT64_MAX;
mutex_init(&vdrz->vn_vre.vre_lock, NULL, MUTEX_DEFAULT, NULL);
cv_init(&vdrz->vn_vre.vre_cv, NULL, CV_DEFAULT, NULL);
zfs_rangelock_init(&vdrz->vn_vre.vre_rangelock, NULL, NULL);
mutex_init(&vdrz->vd_expand_lock, NULL, MUTEX_DEFAULT, NULL);
avl_create(&vdrz->vd_expand_txgs, vdev_raidz_reflow_compare,
sizeof (reflow_node_t), offsetof(reflow_node_t, re_link));
vdrz->vd_physical_width = children;
vdrz->vd_nparity = nparity;
/* note, the ID does not exist when creating a pool */
(void) nvlist_lookup_uint64(nv, ZPOOL_CONFIG_ID,
&vdrz->vn_vre.vre_vdev_id);
boolean_t reflow_in_progress =
nvlist_exists(nv, ZPOOL_CONFIG_RAIDZ_EXPANDING);
if (reflow_in_progress) {
spa->spa_raidz_expand = &vdrz->vn_vre;
vdrz->vn_vre.vre_state = DSS_SCANNING;
}
vdrz->vd_original_width = children;
uint64_t *txgs;
unsigned int txgs_size = 0;
error = nvlist_lookup_uint64_array(nv, ZPOOL_CONFIG_RAIDZ_EXPAND_TXGS,
&txgs, &txgs_size);
if (error == 0) {
for (int i = 0; i < txgs_size; i++) {
reflow_node_t *re = kmem_zalloc(sizeof (*re), KM_SLEEP);
re->re_txg = txgs[txgs_size - i - 1];
re->re_logical_width = vdrz->vd_physical_width - i;
if (reflow_in_progress)
re->re_logical_width--;
avl_add(&vdrz->vd_expand_txgs, re);
}
vdrz->vd_original_width = vdrz->vd_physical_width - txgs_size;
}
if (reflow_in_progress) {
vdrz->vd_original_width--;
zfs_dbgmsg("reflow_in_progress, %u wide, %d prior expansions",
children, txgs_size);
}
*tsd = vdrz;
return (0);
}
static void
vdev_raidz_fini(vdev_t *vd)
{
vdev_raidz_t *vdrz = vd->vdev_tsd;
if (vd->vdev_spa->spa_raidz_expand == &vdrz->vn_vre)
vd->vdev_spa->spa_raidz_expand = NULL;
reflow_node_t *re;
void *cookie = NULL;
avl_tree_t *tree = &vdrz->vd_expand_txgs;
while ((re = avl_destroy_nodes(tree, &cookie)) != NULL)
kmem_free(re, sizeof (*re));
avl_destroy(&vdrz->vd_expand_txgs);
mutex_destroy(&vdrz->vd_expand_lock);
mutex_destroy(&vdrz->vn_vre.vre_lock);
cv_destroy(&vdrz->vn_vre.vre_cv);
zfs_rangelock_fini(&vdrz->vn_vre.vre_rangelock);
kmem_free(vdrz, sizeof (*vdrz));
}
/*
* Add RAIDZ specific fields to the config nvlist.
*/
static void
vdev_raidz_config_generate(vdev_t *vd, nvlist_t *nv)
{
ASSERT3P(vd->vdev_ops, ==, &vdev_raidz_ops);
vdev_raidz_t *vdrz = vd->vdev_tsd;
/*
* Make sure someone hasn't managed to sneak a fancy new vdev
* into a crufty old storage pool.
*/
ASSERT(vdrz->vd_nparity == 1 ||
(vdrz->vd_nparity <= 2 &&
spa_version(vd->vdev_spa) >= SPA_VERSION_RAIDZ2) ||
(vdrz->vd_nparity <= 3 &&
spa_version(vd->vdev_spa) >= SPA_VERSION_RAIDZ3));
/*
* Note that we'll add these even on storage pools where they
* aren't strictly required -- older software will just ignore
* it.
*/
fnvlist_add_uint64(nv, ZPOOL_CONFIG_NPARITY, vdrz->vd_nparity);
if (vdrz->vn_vre.vre_state == DSS_SCANNING) {
fnvlist_add_boolean(nv, ZPOOL_CONFIG_RAIDZ_EXPANDING);
}
mutex_enter(&vdrz->vd_expand_lock);
if (!avl_is_empty(&vdrz->vd_expand_txgs)) {
uint64_t count = avl_numnodes(&vdrz->vd_expand_txgs);
uint64_t *txgs = kmem_alloc(sizeof (uint64_t) * count,
KM_SLEEP);
uint64_t i = 0;
for (reflow_node_t *re = avl_first(&vdrz->vd_expand_txgs);
re != NULL; re = AVL_NEXT(&vdrz->vd_expand_txgs, re)) {
txgs[i++] = re->re_txg;
}
fnvlist_add_uint64_array(nv, ZPOOL_CONFIG_RAIDZ_EXPAND_TXGS,
txgs, count);
kmem_free(txgs, sizeof (uint64_t) * count);
}
mutex_exit(&vdrz->vd_expand_lock);
}
static uint64_t
vdev_raidz_nparity(vdev_t *vd)
{
vdev_raidz_t *vdrz = vd->vdev_tsd;
return (vdrz->vd_nparity);
}
static uint64_t
vdev_raidz_ndisks(vdev_t *vd)
{
return (vd->vdev_children);
}
vdev_ops_t vdev_raidz_ops = {
.vdev_op_init = vdev_raidz_init,
.vdev_op_fini = vdev_raidz_fini,
.vdev_op_open = vdev_raidz_open,
.vdev_op_close = vdev_raidz_close,
.vdev_op_asize = vdev_raidz_asize,
.vdev_op_min_asize = vdev_raidz_min_asize,
.vdev_op_min_alloc = NULL,
.vdev_op_io_start = vdev_raidz_io_start,
.vdev_op_io_done = vdev_raidz_io_done,
.vdev_op_state_change = vdev_raidz_state_change,
.vdev_op_need_resilver = vdev_raidz_need_resilver,
.vdev_op_hold = NULL,
.vdev_op_rele = NULL,
.vdev_op_remap = NULL,
.vdev_op_xlate = vdev_raidz_xlate,
.vdev_op_rebuild_asize = NULL,
.vdev_op_metaslab_init = NULL,
.vdev_op_config_generate = vdev_raidz_config_generate,
.vdev_op_nparity = vdev_raidz_nparity,
.vdev_op_ndisks = vdev_raidz_ndisks,
.vdev_op_type = VDEV_TYPE_RAIDZ, /* name of this vdev type */
.vdev_op_leaf = B_FALSE /* not a leaf vdev */
};
/* BEGIN CSTYLED */
ZFS_MODULE_PARAM(zfs_vdev, raidz_, expand_max_reflow_bytes, ULONG, ZMOD_RW,
"For testing, pause RAIDZ expansion after reflowing this many bytes");
ZFS_MODULE_PARAM(zfs_vdev, raidz_, expand_max_copy_bytes, ULONG, ZMOD_RW,
"Max amount of concurrent i/o for RAIDZ expansion");
ZFS_MODULE_PARAM(zfs_vdev, raidz_, io_aggregate_rows, ULONG, ZMOD_RW,
"For expanded RAIDZ, aggregate reads that have more rows than this");
ZFS_MODULE_PARAM(zfs, zfs_, scrub_after_expand, INT, ZMOD_RW,
"For expanded RAIDZ, automatically start a pool scrub when expansion "
"completes");
/* END CSTYLED */