5b15e2ecaf
Notable changes:
* The only big change is the switch to using a custom QIOChannel for
savevm-async, because the previously used QEMUFileOps was dropped.
Changes to the current implementation:
* Switch to vector based methods as required for an IO channel. For
short reads the passed-in IO vector is stuffed with zeroes at the
end, just to be sure.
* For reading: The documentation in include/io/channel.h states that
at least one byte should be read, so also error out when whe are
at the very end instead of returning 0.
* For reading: Fix off-by-one error when request goes beyond end.
The wrong code piece was:
if ((pos + size) > maxlen) {
size = maxlen - pos - 1;
}
Previously, the last byte would not be read. It's actually
possible to get a snapshot .raw file that has content all the way
up the final 512 byte (= BDRV_SECTOR_SIZE) boundary without any
trailing zero bytes (I wrote a script to do it).
Luckily, it didn't cause a real issue, because qemu_loadvm_state()
is not interested in the final (i.e. QEMU_VM_VMDESCRIPTION)
section. The buffer for reading it is simply freed up afterwards
and the function will assume that it read the whole section, even
if that's not the case.
* For writing: Make use of the generated blk_pwritev() wrapper
instead of manually wrapping the coroutine to simplify and save a
few lines.
* Adapt to changed interfaces for blk_{pread,pwrite}:
* a9262f551e ("block: Change blk_{pread,pwrite}() param order")
* 3b35d4542c ("block: Add a 'flags' param to blk_pread()")
* bf5b16fa40 ("block: Make blk_{pread,pwrite}() return 0 on success")
Those changes especially affected the qemu-img dd patches, because
the context also changed, but also some of our block drivers used
the functions.
* Drop qemu-common.h include: it got renamed after essentially
everything was moved to other headers. The only remaining user I
could find for things dropped from the header between 7.0 and 7.1
was qemu_get_vm_name() in the iscsi-initiatorname patch, but it
already includes the header to which the function was moved.
Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
135 lines
4.9 KiB
Diff
135 lines
4.9 KiB
Diff
From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
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From: Wolfgang Bumiller <w.bumiller@proxmox.com>
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Date: Mon, 6 Apr 2020 12:16:50 +0200
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Subject: [PATCH] PVE: [Up+Config] file-posix: make locking optiono on create
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Otherwise creating images on nfs/cifs can be problematic.
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Signed-off-by: Wolfgang Bumiller <w.bumiller@proxmox.com>
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Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>
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---
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block/file-posix.c | 59 ++++++++++++++++++++++++++++++--------------
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qapi/block-core.json | 3 ++-
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2 files changed, 42 insertions(+), 20 deletions(-)
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diff --git a/block/file-posix.c b/block/file-posix.c
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index 3d60b80286..49ee1db5f9 100644
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--- a/block/file-posix.c
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+++ b/block/file-posix.c
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@@ -2475,6 +2475,7 @@ raw_co_create(BlockdevCreateOptions *options, Error **errp)
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int fd;
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uint64_t perm, shared;
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int result = 0;
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+ bool locked = false;
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/* Validate options and set default values */
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assert(options->driver == BLOCKDEV_DRIVER_FILE);
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@@ -2515,19 +2516,22 @@ raw_co_create(BlockdevCreateOptions *options, Error **errp)
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perm = BLK_PERM_WRITE | BLK_PERM_RESIZE;
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shared = BLK_PERM_ALL & ~BLK_PERM_RESIZE;
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- /* Step one: Take locks */
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- result = raw_apply_lock_bytes(NULL, fd, perm, ~shared, false, errp);
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- if (result < 0) {
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- goto out_close;
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- }
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+ if (file_opts->locking != ON_OFF_AUTO_OFF) {
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+ /* Step one: Take locks */
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+ result = raw_apply_lock_bytes(NULL, fd, perm, ~shared, false, errp);
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+ if (result < 0) {
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+ goto out_close;
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+ }
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+ locked = true;
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- /* Step two: Check that nobody else has taken conflicting locks */
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- result = raw_check_lock_bytes(fd, perm, shared, errp);
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- if (result < 0) {
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- error_append_hint(errp,
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- "Is another process using the image [%s]?\n",
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- file_opts->filename);
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- goto out_unlock;
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+ /* Step two: Check that nobody else has taken conflicting locks */
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+ result = raw_check_lock_bytes(fd, perm, shared, errp);
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+ if (result < 0) {
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+ error_append_hint(errp,
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+ "Is another process using the image [%s]?\n",
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+ file_opts->filename);
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+ goto out_unlock;
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+ }
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}
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/* Clear the file by truncating it to 0 */
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@@ -2581,13 +2585,15 @@ raw_co_create(BlockdevCreateOptions *options, Error **errp)
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}
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out_unlock:
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- raw_apply_lock_bytes(NULL, fd, 0, 0, true, &local_err);
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- if (local_err) {
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- /* The above call should not fail, and if it does, that does
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- * not mean the whole creation operation has failed. So
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- * report it the user for their convenience, but do not report
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- * it to the caller. */
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- warn_report_err(local_err);
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+ if (locked) {
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+ raw_apply_lock_bytes(NULL, fd, 0, 0, true, &local_err);
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+ if (local_err) {
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+ /* The above call should not fail, and if it does, that does
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+ * not mean the whole creation operation has failed. So
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+ * report it the user for their convenience, but do not report
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+ * it to the caller. */
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+ warn_report_err(local_err);
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+ }
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}
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out_close:
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@@ -2612,6 +2618,7 @@ static int coroutine_fn raw_co_create_opts(BlockDriver *drv,
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PreallocMode prealloc;
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char *buf = NULL;
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Error *local_err = NULL;
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+ OnOffAuto locking;
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/* Skip file: protocol prefix */
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strstart(filename, "file:", &filename);
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@@ -2634,6 +2641,18 @@ static int coroutine_fn raw_co_create_opts(BlockDriver *drv,
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return -EINVAL;
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}
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+ locking = qapi_enum_parse(&OnOffAuto_lookup,
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+ qemu_opt_get(opts, "locking"),
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+ ON_OFF_AUTO_AUTO, &local_err);
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+ if (local_err) {
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+ error_propagate(errp, local_err);
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+ return -EINVAL;
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+ }
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+
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+ if (locking == ON_OFF_AUTO_AUTO) {
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+ locking = ON_OFF_AUTO_OFF;
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+ }
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+
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options = (BlockdevCreateOptions) {
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.driver = BLOCKDEV_DRIVER_FILE,
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.u.file = {
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@@ -2645,6 +2664,8 @@ static int coroutine_fn raw_co_create_opts(BlockDriver *drv,
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.nocow = nocow,
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.has_extent_size_hint = has_extent_size_hint,
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.extent_size_hint = extent_size_hint,
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+ .has_locking = true,
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+ .locking = locking,
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},
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};
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return raw_co_create(&options, errp);
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diff --git a/qapi/block-core.json b/qapi/block-core.json
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index e1857e7094..ddac91e8f6 100644
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--- a/qapi/block-core.json
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+++ b/qapi/block-core.json
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@@ -4537,7 +4537,8 @@
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'size': 'size',
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'*preallocation': 'PreallocMode',
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'*nocow': 'bool',
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- '*extent-size-hint': 'size'} }
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+ '*extent-size-hint': 'size',
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+ '*locking': 'OnOffAuto' } }
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##
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# @BlockdevCreateOptionsGluster:
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