Commit Graph

430 Commits

Author SHA1 Message Date
Chunwei Chen
b221f43943 Fix zpl_test_super race with zfs_umount
We cannot call zpl_enter in zpl_test_super, because zpl_test_super is
under spinlock so we can't sleep, and also because zpl_test_super is
called without sb->s_umount taken, so it's possible we would race with
zfs_umount and call zpl_enter on freed zfsvfs.

Here's an stack trace when this happens:
[ 2379.114837] VERIFY(cvp->cv_magic == CV_MAGIC) failed
[ 2379.114845] PANIC at spl-condvar.c:497:__cv_broadcast()
[ 2379.114854] Kernel panic - not syncing: VERIFY(cvp->cv_magic == CV_MAGIC) failed
[ 2379.115012] Call Trace:
[ 2379.115019]  dump_stack+0x74/0x96
[ 2379.115024]  panic+0x114/0x2f6
[ 2379.115035]  spl_panic+0xcf/0xfc [spl]
[ 2379.115477]  __cv_broadcast+0x68/0xa0 [spl]
[ 2379.115585]  rrw_exit+0xb8/0x310 [zfs]
[ 2379.115696]  rrm_exit+0x4a/0x80 [zfs]
[ 2379.115808]  zpl_test_super+0xa9/0xd0 [zfs]
[ 2379.115920]  sget+0xd1/0x230
[ 2379.116033]  zpl_mount+0xdc/0x230 [zfs]
[ 2379.116037]  legacy_get_tree+0x28/0x50
[ 2379.116039]  vfs_get_tree+0x27/0xc0
[ 2379.116045]  path_mount+0x2fe/0xa70
[ 2379.116048]  do_mount+0x80/0xa0
[ 2379.116050]  __x64_sys_mount+0x8b/0xe0
[ 2379.116052]  do_syscall_64+0x35/0x50
[ 2379.116054]  entry_SYSCALL_64_after_hwframe+0x61/0xc6
[ 2379.116057] RIP: 0033:0x7f9912e8b26a

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Chunwei Chen <david.chen@nutanix.com>
Closes #15077
2023-07-21 16:35:12 -07:00
Prakash Surya
945e39fc3a
Enable tuning of ZVOL open timeout value
The default timeout for ZVOL opens may not be sufficient for all cases,
so we should enable the value to be more easily tuned to account for
systems where the default value is insufficient.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Signed-off-by: Prakash Surya <prakash.surya@delphix.com>
Closes #15023
2023-06-30 11:34:05 -07:00
Rich Ercolani
35a6247c5f
Add a delay to tearing down threads.
It's been observed that in certain workloads (zvol-related being a
big one), ZFS will end up spending a large amount of time spinning
up taskqs only to tear them down again almost immediately, then
spin them up again...

I noticed this when I looked at what my mostly-idle system was doing
and wondered how on earth taskq creation/destroy was a bunch of time...

So I added a configurable delay to avoid it tearing down tasks the
first time it notices them idle, and the total number of threads at
steady state went up, but the amount of time being burned just
tearing down/turning up new ones almost vanished.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rich Ercolani <rincebrain@gmail.com>
Closes #14938
2023-06-26 13:57:12 -07:00
Alexander Motin
b3ad3f48d9
Use list_remove_head() where possible.
... instead of list_head() + list_remove().  On FreeBSD the list
functions are not inlined, so in addition to more compact code
this also saves another function call.

Reviewed-by: Brian Atkinson <batkinson@lanl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by:	Alexander Motin <mav@FreeBSD.org>
Sponsored by:	iXsystems, Inc.
Closes #14955
2023-06-09 10:12:52 -07:00
Brian Behlendorf
93f8abeff0
Linux: Never sleep in kmem_cache_alloc(..., KM_NOSLEEP) (#14926)
When a kmem cache is exhausted and needs to be expanded a new
slab is allocated.  KM_SLEEP callers can block and wait for the
allocation, but KM_NOSLEEP callers were incorrectly allowed to
block as well.

Resolve this by attempting an emergency allocation as a best
effort.  This may fail but that's fine since any KM_NOSLEEP
consumer is required to handle an allocation failure.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Adam Moss <c@yotes.com>
Reviewed-by: Brian Atkinson <batkinson@lanl.gov>
Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
2023-06-07 10:43:43 -07:00
Rob Norris
2b9f8ba673 znode: expose zfs_get_zplprop to libzpool
There's no particular reason this function should be kernel-only, and I
want to use it (indirectly) from zdb. I've moved it to zfs_znode.c
because libzpool does not compile in zfs_vfsops.c, and this at least
matches the header its imported from.

Sponsored-By: Klara, Inc.
Reviewed-by: Tino Reichardt <milky-zfs@mcmilk.de>
Reviewed-by: WHR <msl0000023508@gmail.com>
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
Closes #14642
2023-06-05 11:53:44 -07:00
youzhongyang
f8447cf22e
Linux 6.4 compat: reclaimed_slab renamed to reclaimed
Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Reviewed-by: Brian Atkinson <batkinson@lanl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Youzhong Yang <yyang@mathworks.com>
Closes #14891
2023-05-24 12:23:42 -07:00
Richard Yao
ab71b24d20 Linux: zfs_zaccess_trivial() should always call generic_permission()
Building with Clang on Linux generates a warning that err could be
uninitialized if mnt_ns is a NULL pointer. However, mnt_ns should never
be NULL, so there is no need to put this behind an if statement.  Taking
it outside of the if statement means that the possibility of err being
uninitialized goes from being always zero in a way that the compiler
could not realize to a way that is always zero in a way that the
compiler can realize.

Sponsored-By: Wasabi Technology, Inc.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Youzhong Yang <yyang@mathworks.com>
Signed-off-by: Richard Yao <richard.yao@klarasystems.com>
Closes #14738
2023-04-20 10:29:44 -07:00
youzhongyang
d4dc53dad2
Linux 6.3 compat: idmapped mount API changes
Linux kernel 6.3 changed a bunch of APIs to use the dedicated idmap 
type for mounts (struct mnt_idmap), we need to detect these changes 
and make zfs work with the new APIs.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Youzhong Yang <yyang@mathworks.com>
Closes #14682
2023-04-10 14:15:36 -07:00
youzhongyang
8eb2f26057
Linux 6.3 compat: writepage_t first arg struct folio*
The type def of writepage_t in kernel 6.3 is changed to take
struct folio* as the first argument. We need to detect this
change and pass correct function to write_cache_pages().

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Brian Atkinson <batkinson@lanl.gov>
Signed-off-by: Youzhong Yang <yyang@mathworks.com>
Closes #14699
2023-04-05 10:01:38 -07:00
Brian Behlendorf
1142362ff6
Use vmem_zalloc to silence allocation warning
The kmem allocation in zfs_prune_aliases() will trigger a large
allocation warning on systems with 64K pages.  Resolve this by
switching to vmem_alloc() which internally uses kvmalloc() so the
right allocator will be used based on the allocation size.

Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Reviewed-by: Tino Reichardt <milky-zfs@mcmilk.de>
Reviewed-by: Brian Atkinson <batkinson@lanl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #8491
Closes #14694
2023-03-31 09:43:54 -07:00
naivekun
60cfd3bbc2
QAT: Fix uninitialized seed in QAT compression
CpaDcRqResults have to be initialized with checksum=1 for adler32.
Otherwise when error CPA_DC_OVERFLOW occurred, the next compress
operation will continue on previously part-compressed data, and write
invalid checksum data. When zfs decompress the compressed data, a
invalid checksum will occurred and lead to #14463

Reviewed-by: Tino Reichardt <milky-zfs@mcmilk.de>
Reviewed-by: Weigang Li <weigang.li@intel.com>
Reviewed-by: Chengfei Zhu <chengfeix.zhu@intel.com>
Signed-off-by: naivekun <naivekun0817@gmail.com>
Closes #14632
Closes #14463
2023-03-16 11:54:10 -07:00
Richard Yao
d1807f168e nvpair: Constify string functions
After addressing coverity complaints involving `nvpair_name()`, the
compiler started complaining about dropping const. This lead to a rabbit
hole where not only `nvpair_name()` needed to be constified, but also
`nvpair_value_string()`, `fnvpair_value_string()` and a few other static
functions, plus variable pointers throughout the code. The result became
a fairly big change, so it has been split out into its own patch.

Reviewed-by: Tino Reichardt <milky-zfs@mcmilk.de>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes #14612
2023-03-14 15:25:50 -07:00
Richard Yao
703283fabd Linux: Fix octal detection in define_ddi_strtox()
Clang Tidy reported this as a misc-redundant-expression because writing
`8` instead of `'8'` meant that the condition could never be true.

The only place where we have a chance of this being a bug would be in
nvlist_lookup_nvpair_ei_sep(). I am not sure if we ever pass an octal to
that, but if we ever do, it should work properly now instead of failing.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes #14575
2023-03-08 13:52:09 -08:00
Richard Yao
66a38fd10a Linux: Suppress clang static analyzer warning in zfs_remove()
Clang's static analyzer points out that if we fail to find an extended
attribute directory, but somehow find it when calculating delete_now and
delete_now is true, we will have a NULL pointer dereference when we try
to unlink the extended attribute directory.

I am not sure if this is possible, but if it is, I do not see a sane way
of handling this other than rolling back the transaction and retrying.
For now, let us do an VERIFY_IMPLY(). If this trips, it will stop the
transaction from committing, which will prevent an attribute directory
leak.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes #14575
2023-03-08 13:52:04 -08:00
Richard Yao
c2550a136e Linux: Silence static analyzer warning in crypto_create_ctx_template()
A CodeChecker report from Clang's CTU analysis indicated that we were
assigning uninitialized values in crypto_create_ctx_template() when we
call it from zio_crypt_key_init(). This occurs because the ->cm_param
and ->cm_param_len fields are uninitialized. Thankfully, the
uninitialized values are only used in the skein via
KCF_PROV_CREATE_CTX_TEMPLATE() -> skein_create_ctx_template() ->
skein_mac_ctx_build() -> skein_get_digest_bitlen(), but that should not
be called from here. We fix this to avoid a possible trap should this
code change in the future.

The FreeBSD version of zio_crypt_key_init() is unaffected.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes #14575
2023-03-08 13:51:59 -08:00
Richard Yao
5dd0f019cd Linux cleanup: zvol_discard() should only call blk_queue_io_stat() once
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes #14575
2023-03-08 13:51:40 -08:00
Alexander Motin
a8d83e2a24
More adaptive ARC eviction
Traditionally ARC adaptation was limited to MRU/MFU distribution.  But
for years people with metadata-centric workload demanded mechanisms to
also manage data/metadata distribution, that in original ZFS was just
a FIFO.  As result ZFS effectively got separate states for data and
metadata, minimum and maximum metadata limits etc, but it all required
manual tuning, was not adaptive and in its heart remained a bad FIFO.

This change removes most of existing eviction logic, rewriting it from
scratch.  This makes MRU/MFU adaptation individual for data and meta-
data, same as the distribution between data and metadata themselves.
Since most of required states separation was already done, it only
required to make arcs_size state field specific per data/metadata.

The adaptation logic is still based on previous concept of ghost hits,
just now it balances ARC capacity between 4 states: MRU data, MRU
metadata, MFU data and MFU metadata.  To simplify arc_c changes instead
of arc_p measured in bytes, this code uses 3 variable arc_meta, arc_pd
and arc_pm, representing ARC balance between metadata and data, MRU and
MFU for data, and MRU and MFU for metadata respectively as 32-bit fixed
point fractions.  Since we care about the math result only when need to
evict, this moves all the logic from arc_adapt() to arc_evict(), that
reduces per-block overhead, since per-block operations are limited to
stats collection, now moved from arc_adapt() to arc_access() and using
cheaper wmsums.  This also allows to remove ugly ARC_HDR_DO_ADAPT flag
from many places.

This change also removes number of metadata specific tunables, part of
which were actually not functioning correctly, since not all metadata
are equal and some (like L2ARC headers) are not really evictable.
Instead it introduced single opaque knob zfs_arc_meta_balance, tuning
ARC's reaction on ghost hits, allowing administrator give more or less
preference to metadata without setting strict limits.

Some of old code parts like arc_evict_meta() are just removed, because
since introduction of ABD ARC they really make no sense: only headers
referenced by small number of buffers are not evictable, and they are
really not evictable no matter what this code do.  Instead just call
arc_prune_async() if too much metadata appear not evictable.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Allan Jude <allan@klarasystems.com>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Sponsored by: iXsystems, Inc.
Closes #14359
2023-03-08 11:17:23 -08:00
Richard Yao
dd108f5d73
Linux: zfs_fillpage() should handle partial pages from end of file
After 89cd2197b9 was merged, Clang's
static analyzer began complaining about a dead assignment in
`zfs_fillpage()`. Upon inspection, I noticed that the dead assignment
was because we are not using the calculated io_len that we should use to
avoid asking the DMU to read past the end of a file. This should result
in `dmu_buf_hold_array_by_dnode()` calling `zfs_panic_recover()`.

This issue predates 89cd2197b9, but its
simplification of zfs_fillpage() eliminated the only use of the
assignment to io_len, which made Clang's static analyzer complain about
the issue.

Also, as a precaution, we add an assertion that io_offset < i_size. If
this ever fails, bad things will happen. Otherwise, we are blindly
trusting the kernel not to give us invalid offsets. We continue to
blindly trust it on non-debug kernels.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Brian Atkinson <batkinson@lanl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes #14534
2023-03-01 13:19:47 -08:00
John Poduska
73c383f541
Prevent incorrect datasets being mounted
During a mount, zpl_mount_impl(), uses sget() with the callback
zpl_test_super() to find a super_block with a matching objset,
stored in z_os. It does so without taking the teardown lock on
the zfsvfs.

The problem is that operations like rollback will replace the
z_os. And, there is a window where the objset in the rollback
is freed, but z_os still points to it. Then, a mount like
operation, for instance a clone, can reallocate that exact same
pointer and zpl_test_super() will then match the super_block
associated with the rollback as opposed to the clone.

This fix tests for a match and if so, takes the teardown lock
before doing the final match test.

Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: John Poduska <jpoduska@datto.com>
Closes #14518
2023-02-27 16:49:34 -08:00
Brian Behlendorf
89cd2197b9
Fix buffered/direct/mmap I/O race
When a page is faulted in for memory mapped I/O the page lock
may be dropped before it has been read and marked up to date.
If a buffered read encounters such a page in mappedread() it
must wait until the page has been updated. Failure to do so
will result in a panic on debug builds and incorrect data on
production builds.

The critical part of this change is in mappedread() where pages
which are not up to date are now handled. Additionally, it
includes the following simplifications.

- zfs_getpage() and zfs_fillpage() could be passed an array of
  pages. This could be more efficient if it was used but in
  practice only a single page was ever provided. These
  interfaces were simplified to acknowledge that.

- update_pages() was modified to correctly set the PG_error bit
  on a page when it cannot be read by dmu_read().

- Setting PG_error and PG_uptodate was moved to zfs_fillpage()
  from zpl_readpage_common(). This is consistent with the
  handling in update_pages() and mappedread().

- Minor additional refactoring to comments and variable
  declarations to improve readability.

- Add a test case to exercise concurrent buffered, direct,
  and mmap IO to the same file.

- Reduce the mmap_sync test case default run time.

Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Reviewed-by: Brian Atkinson <batkinson@lanl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #13608 
Closes #14498
2023-02-23 10:57:24 -08:00
Brian Behlendorf
3fc92adc40
Linux: use filemap_range_has_page()
As of the 4.13 kernel filemap_range_has_page() can be used to
check if there is a page mapped in a given file range.  When
available this interface should be used which eliminates the
need for the zp->z_is_mapped boolean.

Reviewed-by: Brian Atkinson <batkinson@lanl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #14493
2023-02-14 11:04:34 -08:00
Rich Ercolani
cfd57573ff
quick fix for lingering snapdir unmount problems
Unfortunately, even after e79b6807, I still, much more rarely,
tripped asserts when playing with many ctldir mounts at once.

Since this appears to happen if we dispatched twice too fast, just
ignore it. We don't actually need to do anything if someone already
started doing it for us.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rich Ercolani <rincebrain@gmail.com>
Closes #14462
2023-02-13 16:40:13 -08:00
Prakash Surya
13312e2fa1
Reduce need for contiguous memory for ioctls
We've had cases where we trigger an OOM despite having memory freely
available on the system. For example, here, we had about 21GB free:

    kernel: Node 0 Normal: 2418758*4kB (UME) 1549533*8kB (UE) 0*16kB
    0*32kB 0*64kB 0*128kB 0*256kB 0*512kB 0*1024kB 0*2048kB 0*4096kB =
    22071296kB

The problem being, all the memory is in 4K and 8K contiguous regions,
but the allocation request was for a 16K contiguous region:

    kernel: SafeExecutors-4 invoked oom-killer:
    gfp_mask=0x42dc0(GFP_KERNEL|__GFP_NOWARN|__GFP_COMP|__GFP_ZERO),
    order=2, oom_score_adj=0

The offending allocation came from this call trace:

    kernel: Call Trace:
    kernel:  dump_stack+0x57/0x7a
    kernel:  dump_header+0x4f/0x1e1
    kernel:  oom_kill_process.cold.33+0xb/0x10
    kernel:  out_of_memory+0x1ad/0x490
    kernel:  __alloc_pages_slowpath+0xd55/0xe40
    kernel:  __alloc_pages_nodemask+0x2df/0x330
    kernel:  kmalloc_large_node+0x42/0x90
    kernel:  __kmalloc_node+0x25a/0x320
    kernel:  ? spl_kmem_free_impl+0x21/0x30 [spl]
    kernel:  spl_kmem_alloc_impl+0xa5/0x100 [spl]
    kernel:  spl_kmem_zalloc+0x19/0x20 [spl]
    kernel:  zfsdev_ioctl+0x2b/0xe0 [zfs]
    kernel:  do_vfs_ioctl+0xa9/0x640
    kernel:  ? __audit_syscall_entry+0xdd/0x130
    kernel:  ksys_ioctl+0x67/0x90
    kernel:  __x64_sys_ioctl+0x1a/0x20
    kernel:  do_syscall_64+0x5e/0x200
    kernel:  entry_SYSCALL_64_after_hwframe+0x44/0xa9
    kernel: RIP: 0033:0x7fdca3674317

The problem is, for each ioctl that ZFS makes, it has to allocate a
zfs_cmd_t structure, which is 13744 bytes in size (on my system):

    sdb> sizeof zfs_cmd
    (size_t)13744

This size, coupled with the fact that we currently allocate it with
kmem_zalloc, means we need a 16K contiguous region of memory to satisfy
the request.

The solution taken by this change, is to use "vmem" instead of "kmem" to
do the allocation, such that we don't necessarily need a contiguous 16K
memory region to satisfy the allocation.

Arguably, a better solution would be not to require such a large
allocation to begin with (e.g. reduce the size of the zfs_cmd_t
structure), but that'd be a much larger change than this "one liner".
Thus, I've opted for this approach for now; we can always circle back
and attempt to reduce the size of the structure in the future.

Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Reviewed-by: Mark Maybee <mark.maybee@delphix.com>
Reviewed-by: Don Brady <don.brady@delphix.com>
Signed-off-by: Prakash Surya <prakash.surya@delphix.com>
Closes #14474
2023-02-13 16:35:59 -08:00
Richard Yao
66953686c0 Add assertion and make variables unsigned in abd_alloc_chunks()
Clang's static analyzer pointed out that if alloc_pages >= nr_pages
before the loop, the value of page will be undefined and will be used
anyway. This should not be possible, but as cleanup, we add an
assertion. We also recognize that the local variables should be unsigned
in the first place, so we make them unsigned. This is not enough to
avoid the need for the assertion, since there is still the case that
alloc_pages == nr_pages and nr_pages == 0, which the assertion
implicitly checks.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Brian Atkinson <batkinson@lanl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes #14456
2023-02-06 11:10:50 -08:00
Richard Yao
3a7d2a0ce0 zfs_get_temporary_prop() should not pass NULL to strcpy()
`dsl_dir_activity_in_progress()` can call `zfs_get_temporary_prop()` with
the forth value set to NULL, which will pass NULL to `strcpy()` when
there is a match

Clang's static analyzer caught this with the help of CodeChecker for
Cross Translation Unit analysis.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Brian Atkinson <batkinson@lanl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes #14456
2023-02-06 11:08:57 -08:00
Coleman Kane
9cd71c8604
linux 6.2 compat: zpl_set_acl arg2 is now struct dentry
Linux 6.2 changes the second argument of the set_acl operation to be a
"struct dentry *" rather than a "struct inode *". The inode* parameter
is still available as dentry->d_inode, so adjust the call to the _impl
function call to dereference and pass that pointer to it.

Also document that the get_acl -> get_inode_acl member name change from
commit 884a693 was an API change also introduced in Linux 6.2.

Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Signed-off-by: Coleman Kane <ckane@colemankane.org>
Closes #14415
2023-01-24 11:20:50 -08:00
Chunwei Chen
c6dab6dd39
Fix unprotected zfs_znode_dmu_fini
In original code, zfs_znode_dmu_fini is called in zfs_rmnode without
zfs_znode_hold_enter. It seems to assume it's ok to do so when the znode
is unlinked. However this assumption is not correct, as zfs_zget can be
called by NFS through zpl_fh_to_dentry as pointed out by Christian in
https://github.com/openzfs/zfs/pull/12767, which could result in a
use-after-free bug.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Co-authored-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Chunwei Chen <david.chen@nutanix.com>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes #12767 
Closes #14364
2023-01-19 16:59:05 -08:00
Richard Yao
2e7f664f04
Cleanup of dead code suggested by Clang Static Analyzer (#14380)
I recently gained the ability to run Clang's static analyzer on the
linux kernel modules via a few hacks. This extended coverage to code
that was previously missed since Clang's static analyzer only looked at
code that we built in userspace. Running it against the Linux kernel
modules built from my local branch produced a total of 72 reports
against my local branch. Of those, 50 were reports of logic errors and
22 were reports of dead code. Since we already had cleaned up all of
the previous dead code reports, I felt it would be a good next step to
clean up these dead code reports. Clang did a further breakdown of the
dead code reports into:

Dead assignment	15

Dead increment	2

Dead nested assignment	5

The benefit of cleaning these up, especially in the case of dead nested
assignment, is that they can expose places where our error handling is
incorrect. A number of them were fairly straight forward. However
several were not:

In vdev_disk_physio_completion(), not only were we not using the return
value from the static function vdev_disk_dio_put(), but nothing used it,
so I changed it to return void and removed the existing (void) cast in
the other area where we call it in addition to no longer storing it to a
stack value.

In FSE_createDTable(), the function is dead code. Its helper function
FSE_freeDTable() is also dead code, as are the CPP definitions in
`module/zstd/include/zstd_compat_wrapper.h`. We just delete it all.

In zfs_zevent_wait(), we have an optimization opportunity. cv_wait_sig()
returns 0 if there are waiting signals and 1 if there are none. The
Linux SPL version literally returns `signal_pending(current) ? 0 : 1)`
and FreeBSD implements the same semantics, we can just do
`!cv_wait_sig()` in place of `signal_pending(current)` to avoid
unnecessarily calling it again.

zfs_setattr() on FreeBSD version did not have error handling issue
because the code was removed entirely from FreeBSD version. The error is
from updating the attribute directory's files. After some thought, I
decided to propapage errors on it to userspace.

In zfs_secpolicy_tmp_snapshot(), we ignore a lack of permission from the
first check in favor of checking three other permissions. I assume this
is intentional.

In zfs_create_fs(), the return value of zap_update() was not checked
despite setting an important version number. I see no backward
compatibility reason to permit failures, so we add an assertion to catch
failures. Interestingly, Linux is still using ASSERT(error == 0) from
OpenSolaris while FreeBSD has switched to the improved ASSERT0(error)
from illumos, although illumos has yet to adopt it here. ASSERT(error ==
0) was used on Linux while ASSERT0(error) was used on FreeBSD since the
entire file needs conversion and that should be the subject of
another patch.

dnode_move()'s issue was caused by us not having implemented
POINTER_IS_VALID() on Linux. We have a stub in
`include/os/linux/spl/sys/kmem_cache.h` for it, when it really should be
in `include/os/linux/spl/sys/kmem.h` to be consistent with
Illumos/OpenSolaris. FreeBSD put both `POINTER_IS_VALID()` and
`POINTER_INVALIDATE()` in `include/os/freebsd/spl/sys/kmem.h`, so we
copy what it did.

Whenever a report was in platform-specific code, I checked the FreeBSD
version to see if it also applied to FreeBSD, but it was only relevant a
few times.

Lastly, the patch that enabled Clang's static analyzer to be run on the
Linux kernel modules needs more work before it can be put into a PR. I
plan to do that in the future as part of the on-going static analysis
work that I am doing.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes #14380
2023-01-17 09:57:12 -08:00
Richard Yao
e6328fda2e Cleanup: !A || A && B is equivalent to !A || B
In zfs_zaccess_dataset_check(), we have the following subexpression:

(!IS_DEVVP(ZTOV(zp)) ||
    (IS_DEVVP(ZTOV(zp)) && (v4_mode & WRITE_MASK_ATTRS)))

When !IS_DEVVP(ZTOV(zp)) is false, IS_DEVVP(ZTOV(zp)) is true under the
law of the excluded middle since we are not doing pseudoboolean alegbra.
Therefore doing:

(IS_DEVVP(ZTOV(zp)) && (v4_mode & WRITE_MASK_ATTRS))

Is unnecessary and we can just do:

(v4_mode & WRITE_MASK_ATTRS)

The Linux 5.16.14 kernel's coccicheck caught this. The semantic
patch that caught it was:

./scripts/coccinelle/misc/excluded_middle.cocci

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes #14372
2023-01-12 16:00:15 -08:00
Richard Yao
9c8fabffa2 Cleanup: Replace oldstyle struct hack with C99 flexible array members
The Linux 5.16.14 kernel's coccicheck caught this. The semantic
patch that caught it was:

./scripts/coccinelle/misc/flexible_array.cocci

However, unlike the cases where the GNU zero length array extension had
been used, coccicheck would not suggest patches for the older style
single member arrays. That was good because blindly changing them would
break size calculations in most cases.

Therefore, this required care to make sure that we did not break size
calculations. In the case of `indirect_split_t`, we use
`offsetof(indirect_split_t, is_child[is->is_children])` to calculate
size. This might be subtly wrong according to an old mailing list
thread:

https://inbox.sourceware.org/gcc-prs/20021226123454.27019.qmail@sources.redhat.com/T/

That is because the C99 specification should consider the flexible array
members to start at the end of a structure, but compilers prefer to put
padding at the end. A suggestion was made to allow compilers to allocate
padding after the VLA like compilers already did:

http://std.dkuug.dk/JTC1/SC22/WG14/www/docs/n983.htm

However, upon thinking about it, whether or not we allocate end of
structure padding does not matter, so using offsetof() to calculate the
size of the structure is fine, so long as we do not mix it with sizeof()
on structures with no array members.

In the case that we mix them and padding causes offsetof(struct_t,
vla_member[0]) to differ from sizeof(struct_t), we would be doing unsafe
operations if we underallocate via `offsetof()` and then overcopy via
sizeof().

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes #14372
2023-01-12 16:00:03 -08:00
Richard Yao
d35ccc1f59 Cleanup: Fix indentation in zfs_dbgmsg_t
fdc2d30371 accidentally broke the
indentation.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes #14372
2023-01-12 15:59:56 -08:00
Richard Yao
8e7ebf4e2d Cleanup: Use C99 flexible array members instead of zero length arrays
The Linux 5.16.14 kernel's coccicheck caught this. The semantic
patch that caught it was:

./scripts/coccinelle/misc/flexible_array.cocci

The Linux kernel's documentation makes a good case for why we should not
use these:

https://www.kernel.org/doc/html/latest/process/deprecated.html#zero-length-and-one-element-arrays

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes #14372
2023-01-12 15:59:41 -08:00
Richard Yao
7384ec65cd Cleanup: Remove unnecessary explicit casts of pointers from allocators
The Linux 5.16.14 kernel's coccicheck caught these. The semantic patch
that caught them was:

./scripts/coccinelle/api/alloc/alloc_cast.cocci

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes #14372
2023-01-12 15:59:12 -08:00
Coleman Kane
884a69357f linux 6.2 compat: get_acl() got moved to get_inode_acl() in 6.2
Linux 6.2 renamed the get_acl() operation to get_inode_acl() in
the inode_operations struct. This should fix Issue #14323.

Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Signed-off-by: Coleman Kane <ckane@colemankane.org>
Closes #14323
Closes #14331
2023-01-06 14:40:54 -08:00
Antonio Russo
d27c81847b Linux 6.1 compat: open inside tmpfile()
Linux 863f144 modified the .tmpfile interface to pass a struct file,
rather than a struct dentry, and expect the tmpfile implementation to
open inside of tmpfile().

This patch implements a configuration test that checks for this new API
and appropriately sets a HAVE_TMPFILE_DENTRY flag that tracks this old
API.  Contingent on this flag, the appropriate API is implemented.

Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Antonio Russo <aerusso@aerusso.net>
Closes #14301
Closes #14343
2023-01-06 14:33:00 -08:00
Ameer Hamza
e3785718ba
Skip permission checks for extended attributes
zfs_zaccess_trivial() calls the generic_permission() to read
xattr attributes. This causes deadlock if called from
zpl_xattr_set_dir() context as xattr and the dent locks are
already held in this scenario. This commit skips the permissions
checks for extended attributes since the Linux VFS stack already
checks it before passing us the control.

Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Youzhong Yang <yyang@mathworks.com>
Signed-off-by: Ameer Hamza <ahamza@ixsystems.com>
Closes #14220
2022-12-12 10:21:37 -08:00
Richard Yao
f1100863f7 Linux: Cleanup unnecessary NULL check in __vdev_disk_physio()
zio is never NULL when given to the vdev. Coverity complained saying:

"Either the check against null is unnecessary, or there may be a null
pointer dereference."

Reported-by: Coverity (CID-1466174)
Reviewed-by: Damian Szuberski <szuberskidamian@gmail.com>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes #14263
2022-12-08 13:52:47 -08:00
szubersk
fe975048da Fix Clang 15 compilation errors
- Clang 15 doesn't support `-fno-ipa-sra` anymore. Do a separate
  check for `-fno-ipa-sra` support by $KERNEL_CC.

- Don't enable `-mgeneral-regs-only` for certain module files.
  Fix #13260

- Scope `GCC diagnostic ignored` statements to GCC only. Clang
  doesn't need them to compile the code.

Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: szubersk <szuberskidamian@gmail.com>
Closes #13260
Closes #14150
2022-11-30 13:46:26 -08:00
szubersk
3c1e1933b6 Fix GCC 12 compilation errors
Squelch false positives reported by GCC 12 with UBSan.

Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: szubersk <szuberskidamian@gmail.com>
Closes #14150
2022-11-30 13:45:53 -08:00
Alexander
b5459dd354
Fix the last two CFI callback prototype mismatches
There was the series from me a year ago which fixed most of the
callback vs implementation prototype mismatches. It was based on
running the CFI-enabled kernel (in permissive mode -- warning
instead of panic) and performing a full ZTS cycle, and then fixing
all of the problems caught by CFI.
Now, Clang 16-dev has new warning flag, -Wcast-function-type-strict,
which detect such mismatches at compile-time. It allows to find the
remaining issues missed by the first series.
There are only two of them left: one for the
secpolicy_vnode_setattr() callback and one for taskq_dispatch().
The fix is easy, since they are not used anywhere else.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Alexander Lobakin <alobakin@pm.me>
Closes #14207
2022-11-29 09:56:16 -08:00
Alexander Motin
5f45e3f699
Remove atomics from zh_refcount
It is protected by z_hold_locks, so we do not need more serialization,
simple integer math should be fine.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Signed-off-by:  Alexander Motin <mav@FreeBSD.org>
Closes #14196
2022-11-28 11:36:53 -08:00
Richard Yao
b1eec00904 Cleanup: Suppress Coverity dereference before/after NULL check reports
f224eddf92 began dereferencing a NULL
checked pointer in zpl_vap_init(), which made Coverity complain because
either the dereference is unsafe or the NULL check is unnecessary. Upon
inspection, this pointer is guaranteed to never be NULL because it is
from the Linux kernel VFS. The calls into ZFS simply would not make
sense if this pointer were NULL, so the NULL check is unnecessary.

Reported-by: Coverity (CID 1527260)
Reported-by: Coverity (CID 1527262)
Reviewed-by: Mariusz Zaborski <mariusz.zaborski@klarasystems.com>
Reviewed-by: Youzhong Yang <yyang@mathworks.com>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes #14170
2022-11-10 13:58:05 -08:00
Mariusz Zaborski
16f0fdaddd
Allow to control failfast
Linux defaults to setting "failfast" on BIOs, so that the OS will not
retry IOs that fail, and instead report the error to ZFS.

In some cases, such as errors reported by the HBA driver, not
the device itself, we would wish to retry rather than generating
vdev errors in ZFS. This new property allows that.

This introduces a per vdev option to disable the failfast option.
This also introduces a global module parameter to define the failfast
mask value.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Co-authored-by: Allan Jude <allan@klarasystems.com>
Signed-off-by: Allan Jude <allan@klarasystems.com>
Signed-off-by: Mariusz Zaborski <mariusz.zaborski@klarasystems.com>
Sponsored-by: Seagate Technology LLC
Submitted-by: Klara, Inc.
Closes #14056
2022-11-10 13:37:12 -08:00
Alan Somers
e197bb24f1
Optionally skip zil_close during zvol_create_minor_impl
If there were no zil entries to replay, skip zil_close.  zil_close waits
for a transaction to sync.  That can take several seconds, for example
during pool import of a resilvering pool.  Skipping zil_close can cut
the time for "zpool import" from 2 hours to 45 seconds on a resilvering
pool with a thousand zvols.

Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Sponsored-by: Axcient
Closes #13999 
Closes #14015
2022-11-08 12:38:08 -08:00
youzhongyang
f224eddf92
Support idmapped mount in user namespace
Linux 5.17 commit torvalds/linux@5dfbfe71e enables "the idmapping 
infrastructure to support idmapped mounts of filesystems mounted 
with an idmapping". Update the OpenZFS accordingly to improve the 
idmapped mount support. 

This pull request contains the following changes:

- xattr setter functions are fixed to take mnt_ns argument. Without
  this, cp -p would fail for an idmapped mount in a user namespace.
- idmap_util is enhanced/fixed for its use in a user ns context.
- One test case added to test idmapped mount in a user ns.

Reviewed-by: Christian Brauner <christian@brauner.io>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Youzhong Yang <yyang@mathworks.com>
Closes #14097
2022-11-08 10:28:56 -08:00
Serapheim Dimitropoulos
f66ffe6878
Expose zfs_vdev_open_timeout_ms as a tunable
Some of our customers have been occasionally hitting zfs import failures
in Linux because udevd doesn't create the by-id symbolic links in time
for zpool import to use them. The main issue is that the
systemd-udev-settle.service that zfs-import-cache.service and other
services depend on is racy. There is also an openzfs issue filed (see
https://github.com/openzfs/zfs/issues/10891) outlining the problem and
potential solutions.

With the proper solutions being significant in terms of complexity and
the priority of the issue being low for the time being, this patch
exposes `zfs_vdev_open_timeout_ms` as a tunable so people that are
experiencing this issue often can increase it as a workaround.

Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Don Brady <don.brady@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Closes #14133
2022-11-03 15:02:46 -07:00
Richard Yao
11e3416ae7
Cleanup: Remove branches that always evaluate the same way
Coverity reported that the ASSERT in taskq_create() is always true and
the `*offp > MAXOFFSET_T` check in zfs_file_seek() is always false.

We delete them as cleanup.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes #14130
2022-11-03 10:47:48 -07:00
Brooks Davis
d96303cb07 acl: use uintptr_t for ace walker cookies
Avoid assuming that a pointer can fit in a uint64_t and use uintptr_t
instead.

Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Signed-off-by: Brooks Davis <brooks.davis@sri.com>
Closes #14131
2022-11-03 09:51:34 -07:00
Richard Yao
97143b9d31 Introduce kmem_scnprintf()
`snprintf()` is meant to protect against buffer overflows, but operating
on the buffer using its return value, possibly by calling it again, can
cause a buffer overflow, because it will return how many characters it
would have written if it had enough space even when it did not. In a
number of places, we repeatedly call snprintf() by successively
incrementing a buffer offset and decrementing a buffer length, by its
return value. This is a potentially unsafe usage of `snprintf()`
whenever the buffer length is reached. CodeQL complained about this.

To fix this, we introduce `kmem_scnprintf()`, which will return 0 when
the buffer is zero or the number of written characters, minus 1 to
exclude the NULL character, when the buffer was too small. In all other
cases, it behaves like snprintf(). The name is inspired by the Linux and
XNU kernels' `scnprintf()`. The implementation was written before I
thought to look at `scnprintf()` and had a good name for it, but it
turned out to have identical semantics to the Linux kernel version.
That lead to the name, `kmem_scnprintf()`.

CodeQL only catches this issue in loops, so repeated use of snprintf()
outside of a loop was not caught. As a result, a thorough audit of the
codebase was done to examine all instances of `snprintf()` usage for
potential problems and a few were caught. Fixes for them are included in
this patch.

Unfortunately, ZED is one of the places where `snprintf()` is
potentially used incorrectly. Since using `kmem_scnprintf()` in it would
require changing how it is linked, we modify its usage to make it safe,
no matter what buffer length is used. In addition, there was a bug in
the use of the return value where the NULL format character was not
being written by pwrite(). That has been fixed.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes #14098
2022-10-29 13:05:11 -07:00