extent-tree.h uses btrfs_delayed_ref_head in a function argument but
doesn't pull it's declaration from anywhere, add it to the top of the
header.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
These headers have struct fscrypt_str as function arguments, so add
struct fscrypt_str to the theader, and include linux/fscrypt.h in
btrfs_inode.h as it also needs the definition of struct fscrypt_name for
the new inode args.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We use the iomap code in file.c, include it so we have our dependencies.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We use the unaligned helpers directly in accessors.h, add the include
here.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This is related to the name hashing for dir items, move it into
dir-item.h.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Ideally this would be un-inlined, but that is a cleanup for later. For
now move this into inode-item.h, which is where the extref code lives.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This simply sends the same arguments into crc32c(), and is just used in
a few places. Remove this wrapper and directly call crc32c() in these
instances.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This is the only place this helper is used, take it out of ctree.h and
move it into free-space-cache.c.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The flag EXTENT_NOWAIT is a special flag to notify extent-io-tree code
that this operation should not sleep for the extent state preallocation.
However for btrfs_redirty_list_add(), all callers are able to sleep:
- clean_log_buffer()
Just 2 lines before, we call btrfs_pin_reserved_extent(), which calls
pin_down_extent(), and that function does not require EXTENT_NOWAIT.
Thus we're safe to call it without EXTENT_NOWAIT.
- btrfs_free_tree_block()
This function have several call sites which trigger tree read, e.g.
walk_up_proc(), thus we're safe to call it without EXTENT_NOWAIT.
Thus there is no need to require EXTENT_NOWAIT flag.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Among all the callers, only the device_list_add() function uses the
second argument of alloc_fs_devices(). It passes metadata_uuid when
available, otherwise, it passes NULL. And in turn, alloc_fs_devices()
is designed to copy either metadata_uuid or fsid into
fs_devices::metadata_uuid.
So remove the second argument in alloc_fs_devices(), and always copy the
fsid. In the caller device_list_add() function, we will overwrite it
with metadata_uuid when it is available.
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The second comment at btrfs_delayed_item_reserve_metadata() refers to a
field named "index_items_size" of a delayed inode, however that field
does not exists - it existed in a previous patch version, but then it
split into the fields "curr_index_batch_size" and "index_item_leaves"
in the final patch version that was picked. So update the comment.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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Merge tag 'for-6.6-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fixes from David Sterba:
"A revert of recent mount option parsing fix, this breaks mounts with
security options.
The second patch is a flexible array annotation"
* tag 'for-6.6-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: add __counted_by for struct btrfs_delayed_item and use struct_size()
Revert "btrfs: reject unknown mount options early"
Prepare for the coming implementation by GCC and Clang of the __counted_by
attribute. Flexible array members annotated with __counted_by can have
their accesses bounds-checked at run-time via CONFIG_UBSAN_BOUNDS (for
array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
functions).
While there, use struct_size() helper, instead of the open-coded
version, to calculate the size for the allocation of the whole
flexible structure, including of course, the flexible-array member.
This code was found with the help of Coccinelle, and audited and
fixed manually.
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This reverts commit 5f521494cc.
The patch breaks mounts with security mount options like
$ mount -o context=system_u:object_r:root_t:s0 /dev/sdX /mn
mount: /mnt: wrong fs type, bad option, bad superblock on /dev/sdX, missing codepage or helper program, ...
We cannot reject all unknown options in btrfs_parse_subvol_options() as
intended, the security options can be present at this point and it's not
possible to enumerate them in a future proof way. This means unknown
mount options are silently accepted like before when the filesystem is
mounted with either -o subvol=/path or as followup mounts of the same
device.
Reported-by: Shinichiro Kawasaki <shinichiro.kawasaki@wdc.com
Signed-off-by: David Sterba <dsterba@suse.com>
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Merge tag 'for-6.6-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fixes from David Sterba:
- reject unknown mount options
- adjust transaction abort error message level
- fix one more build warning with -Wmaybe-uninitialized
- proper error handling in several COW-related cases
* tag 'for-6.6-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: error out when reallocating block for defrag using a stale transaction
btrfs: error when COWing block from a root that is being deleted
btrfs: error out when COWing block using a stale transaction
btrfs: always print transaction aborted messages with an error level
btrfs: reject unknown mount options early
btrfs: fix some -Wmaybe-uninitialized warnings in ioctl.c
At btrfs_realloc_node() we have these checks to verify we are not using a
stale transaction (a past transaction with an unblocked state or higher),
and the only thing we do is to trigger two WARN_ON(). This however is a
critical problem, highly unexpected and if it happens it's most likely due
to a bug, so we should error out and turn the fs into error state so that
such issue is much more easily noticed if it's triggered.
The problem is critical because in btrfs_realloc_node() we COW tree blocks,
and using such stale transaction will lead to not persisting the extent
buffers used for the COW operations, as allocating tree block adds the
range of the respective extent buffers to the ->dirty_pages iotree of the
transaction, and a stale transaction, in the unlocked state or higher,
will not flush dirty extent buffers anymore, therefore resulting in not
persisting the tree block and resource leaks (not cleaning the dirty_pages
iotree for example).
So do the following changes:
1) Return -EUCLEAN if we find a stale transaction;
2) Turn the fs into error state, with error -EUCLEAN, so that no
transaction can be committed, and generate a stack trace;
3) Combine both conditions into a single if statement, as both are related
and have the same error message;
4) Mark the check as unlikely, since this is not expected to ever happen.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
At btrfs_cow_block() we check if the block being COWed belongs to a root
that is being deleted and if so we log an error message. However this is
an unexpected case and it indicates a bug somewhere, so we should return
an error and abort the transaction. So change this in the following ways:
1) Abort the transaction with -EUCLEAN, so that if the issue ever happens
it can easily be noticed;
2) Change the logged message level from error to critical, and change the
message itself to print the block's logical address and the ID of the
root;
3) Return -EUCLEAN to the caller;
4) As this is an unexpected scenario, that should never happen, mark the
check as unlikely, allowing the compiler to potentially generate better
code.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
At btrfs_cow_block() we have these checks to verify we are not using a
stale transaction (a past transaction with an unblocked state or higher),
and the only thing we do is to trigger a WARN with a message and a stack
trace. This however is a critical problem, highly unexpected and if it
happens it's most likely due to a bug, so we should error out and turn the
fs into error state so that such issue is much more easily noticed if it's
triggered.
The problem is critical because using such stale transaction will lead to
not persisting the extent buffer used for the COW operation, as allocating
a tree block adds the range of the respective extent buffer to the
->dirty_pages iotree of the transaction, and a stale transaction, in the
unlocked state or higher, will not flush dirty extent buffers anymore,
therefore resulting in not persisting the tree block and resource leaks
(not cleaning the dirty_pages iotree for example).
So do the following changes:
1) Return -EUCLEAN if we find a stale transaction;
2) Turn the fs into error state, with error -EUCLEAN, so that no
transaction can be committed, and generate a stack trace;
3) Combine both conditions into a single if statement, as both are related
and have the same error message;
4) Mark the check as unlikely, since this is not expected to ever happen.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Commit b7af0635c8 ("btrfs: print transaction aborted messages with an
error level") changed the log level of transaction aborted messages from
a debug level to an error level, so that such messages are always visible
even on production systems where the log level is normally above the debug
level (and also on some syzbot reports).
Later, commit fccf0c842e ("btrfs: move btrfs_abort_transaction to
transaction.c") changed the log level back to debug level when the error
number for a transaction abort should not have a stack trace printed.
This happened for absolutely no reason. It's always useful to print
transaction abort messages with an error level, regardless of whether
the error number should cause a stack trace or not.
So change back the log level to error level.
Fixes: fccf0c842e ("btrfs: move btrfs_abort_transaction to transaction.c")
CC: stable@vger.kernel.org # 6.5+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
[BUG]
The following script would allow invalid mount options to be specified
(although such invalid options would just be ignored):
# mkfs.btrfs -f $dev
# mount $dev $mnt1 <<< Successful mount expected
# mount $dev $mnt2 -o junk <<< Failed mount expected
# echo $?
0
[CAUSE]
For the 2nd mount, since the fs is already mounted, we won't go through
open_ctree() thus no btrfs_parse_options(), but only through
btrfs_parse_subvol_options().
However we do not treat unrecognized options from valid but irrelevant
options, thus those invalid options would just be ignored by
btrfs_parse_subvol_options().
[FIX]
Add the handling for Opt_err to handle invalid options and error out,
while still ignore other valid options inside btrfs_parse_subvol_options().
Reported-by: Anand Jain <anand.jain@oracle.com>
CC: stable@vger.kernel.org # 4.14+
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Jens reported the following warnings from -Wmaybe-uninitialized recent
Linus' branch.
In file included from ./include/asm-generic/rwonce.h:26,
from ./arch/arm64/include/asm/rwonce.h:71,
from ./include/linux/compiler.h:246,
from ./include/linux/export.h:5,
from ./include/linux/linkage.h:7,
from ./include/linux/kernel.h:17,
from fs/btrfs/ioctl.c:6:
In function ‘instrument_copy_from_user_before’,
inlined from ‘_copy_from_user’ at ./include/linux/uaccess.h:148:3,
inlined from ‘copy_from_user’ at ./include/linux/uaccess.h:183:7,
inlined from ‘btrfs_ioctl_space_info’ at fs/btrfs/ioctl.c:2999:6,
inlined from ‘btrfs_ioctl’ at fs/btrfs/ioctl.c:4616:10:
./include/linux/kasan-checks.h:38:27: warning: ‘space_args’ may be used
uninitialized [-Wmaybe-uninitialized]
38 | #define kasan_check_write __kasan_check_write
./include/linux/instrumented.h:129:9: note: in expansion of macro
‘kasan_check_write’
129 | kasan_check_write(to, n);
| ^~~~~~~~~~~~~~~~~
./include/linux/kasan-checks.h: In function ‘btrfs_ioctl’:
./include/linux/kasan-checks.h:20:6: note: by argument 1 of type ‘const
volatile void *’ to ‘__kasan_check_write’ declared here
20 | bool __kasan_check_write(const volatile void *p, unsigned int
size);
| ^~~~~~~~~~~~~~~~~~~
fs/btrfs/ioctl.c:2981:39: note: ‘space_args’ declared here
2981 | struct btrfs_ioctl_space_args space_args;
| ^~~~~~~~~~
In function ‘instrument_copy_from_user_before’,
inlined from ‘_copy_from_user’ at ./include/linux/uaccess.h:148:3,
inlined from ‘copy_from_user’ at ./include/linux/uaccess.h:183:7,
inlined from ‘_btrfs_ioctl_send’ at fs/btrfs/ioctl.c:4343:9,
inlined from ‘btrfs_ioctl’ at fs/btrfs/ioctl.c:4658:10:
./include/linux/kasan-checks.h:38:27: warning: ‘args32’ may be used
uninitialized [-Wmaybe-uninitialized]
38 | #define kasan_check_write __kasan_check_write
./include/linux/instrumented.h:129:9: note: in expansion of macro
‘kasan_check_write’
129 | kasan_check_write(to, n);
| ^~~~~~~~~~~~~~~~~
./include/linux/kasan-checks.h: In function ‘btrfs_ioctl’:
./include/linux/kasan-checks.h:20:6: note: by argument 1 of type ‘const
volatile void *’ to ‘__kasan_check_write’ declared here
20 | bool __kasan_check_write(const volatile void *p, unsigned int
size);
| ^~~~~~~~~~~~~~~~~~~
fs/btrfs/ioctl.c:4341:49: note: ‘args32’ declared here
4341 | struct btrfs_ioctl_send_args_32 args32;
| ^~~~~~
This was due to his config options and having KASAN turned on,
which adds some extra checks around copy_from_user(), which then
triggered the -Wmaybe-uninitialized checker for these cases.
Fix the warnings by initializing the different structs we're copying
into.
Reported-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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Merge tag 'for-6.6-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fixes from David Sterba:
- delayed refs fixes:
- fix race when refilling delayed refs block reserve
- prevent transaction block reserve underflow when starting
transaction
- error message and value adjustments
- fix build warnings with CONFIG_CC_OPTIMIZE_FOR_SIZE and
-Wmaybe-uninitialized
- fix for smatch report where uninitialized data from invalid extent
buffer range could be returned to the caller
- fix numeric overflow in statfs when calculating lower threshold
for a full filesystem
* tag 'for-6.6-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: initialize start_slot in btrfs_log_prealloc_extents
btrfs: make sure to initialize start and len in find_free_dev_extent
btrfs: reset destination buffer when read_extent_buffer() gets invalid range
btrfs: properly report 0 avail for very full file systems
btrfs: log message if extent item not found when running delayed extent op
btrfs: remove redundant BUG_ON() from __btrfs_inc_extent_ref()
btrfs: return -EUCLEAN for delayed tree ref with a ref count not equals to 1
btrfs: prevent transaction block reserve underflow when starting transaction
btrfs: fix race when refilling delayed refs block reserve
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Merge tag 'v6.6-rc3.vfs.ctime.revert' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull finegrained timestamp reverts from Christian Brauner:
"Earlier this week we sent a few minor fixes for the multi-grained
timestamp work in [1]. While we were polishing those up after Linus
realized that there might be a nicer way to fix them we received a
regression report in [2] that fine grained timestamps break gnulib
tests and thus possibly other tools.
The kernel will elide fine-grain timestamp updates when no one is
actively querying for them to avoid performance impacts. So a sequence
like write(f1) stat(f2) write(f2) stat(f2) write(f1) stat(f1) may
result in timestamp f1 to be older than the final f2 timestamp even
though f1 was last written too but the second write didn't update the
timestamp.
Such plotholes can lead to subtle bugs when programs compare
timestamps. For example, the nap() function in [2] will estimate that
it needs to wait one ns on a fine-grain timestamp enabled filesytem
between subsequent calls to observe a timestamp change. But in general
we don't update timestamps with more than one jiffie if we think that
no one is actively querying for fine-grain timestamps to avoid
performance impacts.
While discussing various fixes the decision was to go back to the
drawing board and ultimately to explore a solution that involves only
exposing such fine-grained timestamps to nfs internally and never to
userspace.
As there are multiple solutions discussed the honest thing to do here
is not to fix this up or disable it but to cleanly revert. The general
infrastructure will probably come back but there is no reason to keep
this code in mainline.
The general changes to timestamp handling are valid and a good cleanup
that will stay. The revert is fully bisectable"
Link: https://lore.kernel.org/all/20230918-hirte-neuzugang-4c2324e7bae3@brauner [1]
Link: https://lore.kernel.org/all/bf0524debb976627693e12ad23690094e4514303.camel@linuxfromscratch.org [2]
* tag 'v6.6-rc3.vfs.ctime.revert' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
Revert "fs: add infrastructure for multigrain timestamps"
Revert "btrfs: convert to multigrain timestamps"
Revert "ext4: switch to multigrain timestamps"
Revert "xfs: switch to multigrain timestamps"
Revert "tmpfs: add support for multigrain timestamps"
Jens reported a compiler warning when using
CONFIG_CC_OPTIMIZE_FOR_SIZE=y that looks like this
fs/btrfs/tree-log.c: In function ‘btrfs_log_prealloc_extents’:
fs/btrfs/tree-log.c:4828:23: warning: ‘start_slot’ may be used
uninitialized [-Wmaybe-uninitialized]
4828 | ret = copy_items(trans, inode, dst_path, path,
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
4829 | start_slot, ins_nr, 1, 0);
| ~~~~~~~~~~~~~~~~~~~~~~~~~
fs/btrfs/tree-log.c:4725:13: note: ‘start_slot’ was declared here
4725 | int start_slot;
| ^~~~~~~~~~
The compiler is incorrect, as we only use this code when ins_len > 0,
and when ins_len > 0 we have start_slot properly initialized. However
we generally find the -Wmaybe-uninitialized warnings valuable, so
initialize start_slot to get rid of the warning.
Reported-by: Jens Axboe <axboe@kernel.dk>
Tested-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Jens reported a compiler error when using CONFIG_CC_OPTIMIZE_FOR_SIZE=y
that looks like this
In function ‘gather_device_info’,
inlined from ‘btrfs_create_chunk’ at fs/btrfs/volumes.c:5507:8:
fs/btrfs/volumes.c:5245:48: warning: ‘dev_offset’ may be used uninitialized [-Wmaybe-uninitialized]
5245 | devices_info[ndevs].dev_offset = dev_offset;
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~
fs/btrfs/volumes.c: In function ‘btrfs_create_chunk’:
fs/btrfs/volumes.c:5196:13: note: ‘dev_offset’ was declared here
5196 | u64 dev_offset;
This occurs because find_free_dev_extent is responsible for setting
dev_offset, however if we get an -ENOMEM at the top of the function
we'll return without setting the value.
This isn't actually a problem because we will see the -ENOMEM in
gather_device_info() and return and not use the uninitialized value,
however we also just don't want the compiler warning so rework the code
slightly in find_free_dev_extent() to make sure it's always setting
*start and *len to avoid the compiler warning.
Reported-by: Jens Axboe <axboe@kernel.dk>
Tested-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Commit f98b6215d7 ("btrfs: extent_io: do extra check for extent buffer
read write functions") changed how we handle invalid extent buffer range
for read_extent_buffer().
Previously if the range is invalid we just set the destination to zero,
but after the patch we do nothing and error out.
This can lead to smatch static checker errors like:
fs/btrfs/print-tree.c:186 print_uuid_item() error: uninitialized symbol 'subvol_id'.
fs/btrfs/tests/extent-io-tests.c:338 check_eb_bitmap() error: uninitialized symbol 'has'.
fs/btrfs/tests/extent-io-tests.c:353 check_eb_bitmap() error: uninitialized symbol 'has'.
fs/btrfs/uuid-tree.c:203 btrfs_uuid_tree_remove() error: uninitialized symbol 'read_subid'.
fs/btrfs/uuid-tree.c:353 btrfs_uuid_tree_iterate() error: uninitialized symbol 'subid_le'.
fs/btrfs/uuid-tree.c:72 btrfs_uuid_tree_lookup() error: uninitialized symbol 'data'.
fs/btrfs/volumes.c:7415 btrfs_dev_stats_value() error: uninitialized symbol 'val'.
Fix those warnings by reverting back to the old memset() behavior.
By this we keep the static checker happy and would still make a lot of
noise when such invalid ranges are passed in.
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Fixes: f98b6215d7 ("btrfs: extent_io: do extra check for extent buffer read write functions")
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
A user reported some issues with smaller file systems that get very
full. While investigating this issue I noticed that df wasn't showing
100% full, despite having 0 chunk space and having < 1MiB of available
metadata space.
This turns out to be an overflow issue, we're doing:
total_available_metadata_space - SZ_4M < global_block_rsv_size
to determine if there's not enough space to make metadata allocations,
which overflows if total_available_metadata_space is < 4M. Fix this by
checking to see if our available space is greater than the 4M threshold.
This makes df properly report 100% usage on the file system.
CC: stable@vger.kernel.org # 4.14+
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When running a delayed extent operation, if we don't find the extent item
in the extent tree we just return -EIO without any logged message. This
indicates some bug or possibly a memory or fs corruption, so the return
value should not be -EIO but -EUCLEAN instead, and since it's not expected
to ever happen, print an informative error message so that if it happens
we have some idea of what went wrong, where to look at.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
At __btrfs_inc_extent_ref() we are doing a BUG_ON() if we are dealing with
a tree block reference that has a reference count that is different from 1,
but we have already dealt with this case at run_delayed_tree_ref(), making
it useless. So remove the BUG_ON().
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When running a delayed tree reference, if we find a ref count different
from 1, we return -EIO. This isn't an IO error, as it indicates either a
bug in the delayed refs code or a memory corruption, so change the error
code from -EIO to -EUCLEAN. Also tag the branch as 'unlikely' as this is
not expected to ever happen, and change the error message to print the
tree block's bytenr without the parenthesis (and there was a missing space
between the 'block' word and the opening parenthesis), for consistency as
that's the style we used everywhere else.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When starting a transaction, with a non-zero number of items, we reserve
metadata space for that number of items and for delayed refs by doing a
call to btrfs_block_rsv_add(), with the transaction block reserve passed
as the block reserve argument. This reserves metadata space and adds it
to the transaction block reserve. Later we migrate the space we reserved
for delayed references from the transaction block reserve into the delayed
refs block reserve, by calling btrfs_migrate_to_delayed_refs_rsv().
btrfs_migrate_to_delayed_refs_rsv() decrements the number of bytes to
migrate from the source block reserve, and this however may result in an
underflow in case the space added to the transaction block reserve ended
up being used by another task that has not reserved enough space for its
own use - examples are tasks doing reflinks or hole punching because they
end up calling btrfs_replace_file_extents() -> btrfs_drop_extents() and
may need to modify/COW a variable number of leaves/paths, so they keep
trying to use space from the transaction block reserve when they need to
COW an extent buffer, and may end up trying to use more space then they
have reserved (1 unit/path only for removing file extent items).
This can be avoided by simply reserving space first without adding it to
the transaction block reserve, then add the space for delayed refs to the
delayed refs block reserve and finally add the remaining reserved space
to the transaction block reserve. This also makes the code a bit shorter
and simpler. So just do that.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
If we have two (or more) tasks attempting to refill the delayed refs block
reserve we can end up with the delayed block reserve being over reserved,
that is, with a reserved space greater than its size. If this happens, we
are holding to more reserved space than necessary for a while.
The race happens like this:
1) The delayed refs block reserve has a size of 8M and a reserved space of
6M for example;
2) Task A calls btrfs_delayed_refs_rsv_refill();
3) Task B also calls btrfs_delayed_refs_rsv_refill();
4) Task A sees there's a 2M difference between the size and the reserved
space of the delayed refs rsv, so it will reserve 2M of space by
calling btrfs_reserve_metadata_bytes();
5) Task B also sees that 2M difference, and like task A, it reserves
another 2M of metadata space;
6) Both task A and task B increase the reserved space of block reserve
by 2M, by calling btrfs_block_rsv_add_bytes(), so the block reserve
ends up with a size of 8M and a reserved space of 10M;
7) The extra, over reserved space will eventually be freed by some task
calling btrfs_delayed_refs_rsv_release() -> btrfs_block_rsv_release()
-> block_rsv_release_bytes(), as there we will detect the over reserve
and release that space.
So fix this by checking if we still need to add space to the delayed refs
block reserve after reserving the metadata space, and if we don't, just
release that space immediately.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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Merge tag 'for-6.6-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fixes from David Sterba:
"A few more followup fixes to the directory listing.
People have noticed different behaviour compared to other filesystems
after changes in 6.5. This is now unified to more "logical" and
expected behaviour while still within POSIX. And a few more fixes for
stable.
- change behaviour of readdir()/rewinddir() when new directory
entries are created after opendir(), properly tracking the last
entry
- fix race in readdir when multiple threads can set the last entry
index for a directory
Additionally:
- use exclusive lock when direct io might need to drop privs and call
notify_change()
- don't clear uptodate bit on page after an error, this may lead to a
deadlock in subpage mode
- fix waiting pattern when multiple readers block on Merkle tree
data, switch to folios"
* tag 'for-6.6-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: fix race between reading a directory and adding entries to it
btrfs: refresh dir last index during a rewinddir(3) call
btrfs: set last dir index to the current last index when opening dir
btrfs: don't clear uptodate on write errors
btrfs: file_remove_privs needs an exclusive lock in direct io write
btrfs: convert btrfs_read_merkle_tree_page() to use a folio
This reverts commit 50e9ceef1d.
Users reported regressions due to enabling multi-grained timestamps
unconditionally. As no clear consensus on a solution has come up and the
discussion has gone back to the drawing board revert the infrastructure
changes for. If it isn't code that's here to stay, make it go away.
Message-ID: <20230920-keine-eile-c9755b5825db@brauner>
Acked-by: Jan Kara <jack@suse.cz>
Acked-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
When opening a directory (opendir(3)) or rewinding it (rewinddir(3)), we
are not holding the directory's inode locked, and this can result in later
attempting to add two entries to the directory with the same index number,
resulting in a transaction abort, with -EEXIST (-17), when inserting the
second delayed dir index. This results in a trace like the following:
Sep 11 22:34:59 myhostname kernel: BTRFS error (device dm-3): err add delayed dir index item(name: cockroach-stderr.log) into the insertion tree of the delayed node(root id: 5, inode id: 4539217, errno: -17)
Sep 11 22:34:59 myhostname kernel: ------------[ cut here ]------------
Sep 11 22:34:59 myhostname kernel: kernel BUG at fs/btrfs/delayed-inode.c:1504!
Sep 11 22:34:59 myhostname kernel: invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
Sep 11 22:34:59 myhostname kernel: CPU: 0 PID: 7159 Comm: cockroach Not tainted 6.4.15-200.fc38.x86_64 #1
Sep 11 22:34:59 myhostname kernel: Hardware name: ASUS ESC500 G3/P9D WS, BIOS 2402 06/27/2018
Sep 11 22:34:59 myhostname kernel: RIP: 0010:btrfs_insert_delayed_dir_index+0x1da/0x260
Sep 11 22:34:59 myhostname kernel: Code: eb dd 48 (...)
Sep 11 22:34:59 myhostname kernel: RSP: 0000:ffffa9980e0fbb28 EFLAGS: 00010282
Sep 11 22:34:59 myhostname kernel: RAX: 0000000000000000 RBX: ffff8b10b8f4a3c0 RCX: 0000000000000000
Sep 11 22:34:59 myhostname kernel: RDX: 0000000000000000 RSI: ffff8b177ec21540 RDI: ffff8b177ec21540
Sep 11 22:34:59 myhostname kernel: RBP: ffff8b110cf80888 R08: 0000000000000000 R09: ffffa9980e0fb938
Sep 11 22:34:59 myhostname kernel: R10: 0000000000000003 R11: ffffffff86146508 R12: 0000000000000014
Sep 11 22:34:59 myhostname kernel: R13: ffff8b1131ae5b40 R14: ffff8b10b8f4a418 R15: 00000000ffffffef
Sep 11 22:34:59 myhostname kernel: FS: 00007fb14a7fe6c0(0000) GS:ffff8b177ec00000(0000) knlGS:0000000000000000
Sep 11 22:34:59 myhostname kernel: CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
Sep 11 22:34:59 myhostname kernel: CR2: 000000c00143d000 CR3: 00000001b3b4e002 CR4: 00000000001706f0
Sep 11 22:34:59 myhostname kernel: Call Trace:
Sep 11 22:34:59 myhostname kernel: <TASK>
Sep 11 22:34:59 myhostname kernel: ? die+0x36/0x90
Sep 11 22:34:59 myhostname kernel: ? do_trap+0xda/0x100
Sep 11 22:34:59 myhostname kernel: ? btrfs_insert_delayed_dir_index+0x1da/0x260
Sep 11 22:34:59 myhostname kernel: ? do_error_trap+0x6a/0x90
Sep 11 22:34:59 myhostname kernel: ? btrfs_insert_delayed_dir_index+0x1da/0x260
Sep 11 22:34:59 myhostname kernel: ? exc_invalid_op+0x50/0x70
Sep 11 22:34:59 myhostname kernel: ? btrfs_insert_delayed_dir_index+0x1da/0x260
Sep 11 22:34:59 myhostname kernel: ? asm_exc_invalid_op+0x1a/0x20
Sep 11 22:34:59 myhostname kernel: ? btrfs_insert_delayed_dir_index+0x1da/0x260
Sep 11 22:34:59 myhostname kernel: ? btrfs_insert_delayed_dir_index+0x1da/0x260
Sep 11 22:34:59 myhostname kernel: btrfs_insert_dir_item+0x200/0x280
Sep 11 22:34:59 myhostname kernel: btrfs_add_link+0xab/0x4f0
Sep 11 22:34:59 myhostname kernel: ? ktime_get_real_ts64+0x47/0xe0
Sep 11 22:34:59 myhostname kernel: btrfs_create_new_inode+0x7cd/0xa80
Sep 11 22:34:59 myhostname kernel: btrfs_symlink+0x190/0x4d0
Sep 11 22:34:59 myhostname kernel: ? schedule+0x5e/0xd0
Sep 11 22:34:59 myhostname kernel: ? __d_lookup+0x7e/0xc0
Sep 11 22:34:59 myhostname kernel: vfs_symlink+0x148/0x1e0
Sep 11 22:34:59 myhostname kernel: do_symlinkat+0x130/0x140
Sep 11 22:34:59 myhostname kernel: __x64_sys_symlinkat+0x3d/0x50
Sep 11 22:34:59 myhostname kernel: do_syscall_64+0x5d/0x90
Sep 11 22:34:59 myhostname kernel: ? syscall_exit_to_user_mode+0x2b/0x40
Sep 11 22:34:59 myhostname kernel: ? do_syscall_64+0x6c/0x90
Sep 11 22:34:59 myhostname kernel: entry_SYSCALL_64_after_hwframe+0x72/0xdc
The race leading to the problem happens like this:
1) Directory inode X is loaded into memory, its ->index_cnt field is
initialized to (u64)-1 (at btrfs_alloc_inode());
2) Task A is adding a new file to directory X, holding its vfs inode lock,
and calls btrfs_set_inode_index() to get an index number for the entry.
Because the inode's index_cnt field is set to (u64)-1 it calls
btrfs_inode_delayed_dir_index_count() which fails because no dir index
entries were added yet to the delayed inode and then it calls
btrfs_set_inode_index_count(). This functions finds the last dir index
key and then sets index_cnt to that index value + 1. It found that the
last index key has an offset of 100. However before it assigns a value
of 101 to index_cnt...
3) Task B calls opendir(3), ending up at btrfs_opendir(), where the VFS
lock for inode X is not taken, so it calls btrfs_get_dir_last_index()
and sees index_cnt still with a value of (u64)-1. Because of that it
calls btrfs_inode_delayed_dir_index_count() which fails since no dir
index entries were added to the delayed inode yet, and then it also
calls btrfs_set_inode_index_count(). This also finds that the last
index key has an offset of 100, and before it assigns the value 101
to the index_cnt field of inode X...
4) Task A assigns a value of 101 to index_cnt. And then the code flow
goes to btrfs_set_inode_index() where it increments index_cnt from
101 to 102. Task A then creates a delayed dir index entry with a
sequence number of 101 and adds it to the delayed inode;
5) Task B assigns 101 to the index_cnt field of inode X;
6) At some later point when someone tries to add a new entry to the
directory, btrfs_set_inode_index() will return 101 again and shortly
after an attempt to add another delayed dir index key with index
number 101 will fail with -EEXIST resulting in a transaction abort.
Fix this by locking the inode at btrfs_get_dir_last_index(), which is only
only used when opening a directory or attempting to lseek on it.
Reported-by: ken <ken@bllue.org>
Link: https://lore.kernel.org/linux-btrfs/CAE6xmH+Lp=Q=E61bU+v9eWX8gYfLvu6jLYxjxjFpo3zHVPR0EQ@mail.gmail.com/
Reported-by: syzbot+d13490c82ad5353c779d@syzkaller.appspotmail.com
Link: https://lore.kernel.org/linux-btrfs/00000000000036e1290603e097e0@google.com/
Fixes: 9b378f6ad4 ("btrfs: fix infinite directory reads")
CC: stable@vger.kernel.org # 6.5+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When opening a directory we find what's the index of its last entry and
then store it in the directory's file handle private data (struct
btrfs_file_private::last_index), so that in the case new directory entries
are added to a directory after an opendir(3) call we don't end up in an
infinite loop (see commit 9b378f6ad4 ("btrfs: fix infinite directory
reads")) when calling readdir(3).
However once rewinddir(3) is called, POSIX states [1] that any new
directory entries added after the previous opendir(3) call, must be
returned by subsequent calls to readdir(3):
"The rewinddir() function shall reset the position of the directory
stream to which dirp refers to the beginning of the directory.
It shall also cause the directory stream to refer to the current
state of the corresponding directory, as a call to opendir() would
have done."
We currently don't refresh the last_index field of the struct
btrfs_file_private associated to the directory, so after a rewinddir(3)
we are not returning any new entries added after the opendir(3) call.
Fix this by finding the current last index of the directory when llseek
is called against the directory.
This can be reproduced by the following C program provided by Ian Johnson:
#include <dirent.h>
#include <stdio.h>
int main(void) {
DIR *dir = opendir("test");
FILE *file;
file = fopen("test/1", "w");
fwrite("1", 1, 1, file);
fclose(file);
file = fopen("test/2", "w");
fwrite("2", 1, 1, file);
fclose(file);
rewinddir(dir);
struct dirent *entry;
while ((entry = readdir(dir))) {
printf("%s\n", entry->d_name);
}
closedir(dir);
return 0;
}
Reported-by: Ian Johnson <ian@ianjohnson.dev>
Link: https://lore.kernel.org/linux-btrfs/YR1P0S.NGASEG570GJ8@ianjohnson.dev/
Fixes: 9b378f6ad4 ("btrfs: fix infinite directory reads")
CC: stable@vger.kernel.org # 6.5+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When opening a directory for reading it, we set the last index where we
stop iteration to the value in struct btrfs_inode::index_cnt. That value
does not match the index of the most recently added directory entry but
it's instead the index number that will be assigned the next directory
entry.
This means that if after the call to opendir(3) new directory entries are
added, a readdir(3) call will return the first new directory entry. This
is fine because POSIX says the following [1]:
"If a file is removed from or added to the directory after the most
recent call to opendir() or rewinddir(), whether a subsequent call to
readdir() returns an entry for that file is unspecified."
For example for the test script from commit 9b378f6ad4 ("btrfs: fix
infinite directory reads"), where we have 2000 files in a directory, ext4
doesn't return any new directory entry after opendir(3), while xfs returns
the first 13 new directory entries added after the opendir(3) call.
If we move to a shorter example with an empty directory when opendir(3) is
called, and 2 files added to the directory after the opendir(3) call, then
readdir(3) on btrfs will return the first file, ext4 and xfs return the 2
files (but in a different order). A test program for this, reported by
Ian Johnson, is the following:
#include <dirent.h>
#include <stdio.h>
int main(void) {
DIR *dir = opendir("test");
FILE *file;
file = fopen("test/1", "w");
fwrite("1", 1, 1, file);
fclose(file);
file = fopen("test/2", "w");
fwrite("2", 1, 1, file);
fclose(file);
struct dirent *entry;
while ((entry = readdir(dir))) {
printf("%s\n", entry->d_name);
}
closedir(dir);
return 0;
}
To make this less odd, change the behaviour to never return new entries
that were added after the opendir(3) call. This is done by setting the
last_index field of the struct btrfs_file_private attached to the
directory's file handle with a value matching btrfs_inode::index_cnt
minus 1, since that value always matches the index of the next new
directory entry and not the index of the most recently added entry.
[1] https://pubs.opengroup.org/onlinepubs/007904875/functions/readdir_r.html
Link: https://lore.kernel.org/linux-btrfs/YR1P0S.NGASEG570GJ8@ianjohnson.dev/
CC: stable@vger.kernel.org # 6.5+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We have been consistently seeing hangs with generic/648 in our subpage
GitHub CI setup. This is a classic deadlock, we are calling
btrfs_read_folio() on a folio, which requires holding the folio lock on
the folio, and then finding a ordered extent that overlaps that range
and calling btrfs_start_ordered_extent(), which then tries to write out
the dirty page, which requires taking the folio lock and then we
deadlock.
The hang happens because we're writing to range [1271750656, 1271767040),
page index [77621, 77622], and page 77621 is !Uptodate. It is also Dirty,
so we call btrfs_read_folio() for 77621 and which does
btrfs_lock_and_flush_ordered_range() for that range, and we find an ordered
extent which is [1271644160, 1271746560), page index [77615, 77621].
The page indexes overlap, but the actual bytes don't overlap. We're
holding the page lock for 77621, then call
btrfs_lock_and_flush_ordered_range() which tries to flush the dirty
page, and tries to lock 77621 again and then we deadlock.
The byte ranges do not overlap, but with subpage support if we clear
uptodate on any portion of the page we mark the entire thing as not
uptodate.
We have been clearing page uptodate on write errors, but no other file
system does this, and is in fact incorrect. This doesn't hurt us in the
!subpage case because we can't end up with overlapped ranges that don't
also overlap on the page.
Fix this by not clearing uptodate when we have a write error. The only
thing we should be doing in this case is setting the mapping error and
carrying on. This makes it so we would no longer call
btrfs_read_folio() on the page as it's uptodate and eliminates the
deadlock.
With this patch we're now able to make it through a full fstests run on
our subpage blocksize VMs.
Note for stable backports: this probably goes beyond 6.1 but the code
has been cleaned up and clearing the uptodate bit must be verified on
each version independently.
CC: stable@vger.kernel.org # 6.1+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This was noticed by Miklos that file_remove_privs might call into
notify_change(), which requires to hold an exclusive lock. The problem
exists in FUSE and btrfs. We can fix it without any additional helpers
from VFS, in case the privileges would need to be dropped, change the
lock type to be exclusive and redo the loop.
Fixes: e9adabb971 ("btrfs: use shared lock for direct writes within EOF")
CC: Miklos Szeredi <miklos@szeredi.hu>
CC: stable@vger.kernel.org # 5.15+
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Bernd Schubert <bschubert@ddn.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Remove a number of hidden calls to compound_head() by using a folio
throughout. Also follow core kernel coding style by adding the folio to
the page cache immediately after allocation instead of doing the read
first, then adding it to the page cache. This ordering makes subsequent
readers block waiting for the first reader instead of duplicating the
work only to throw it away when they find out they lost the race.
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: David Sterba <dsterba@suse.com>
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Merge tag 'for-6.6-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fixes from David Sterba:
- several fixes for handling directory item (inserting, removing,
iteration, error handling)
- fix transaction commit stalls when auto relocation is running and
blocks other tasks that want to commit
- fix a build error when DEBUG is enabled
- fix lockdep warning in inode number lookup ioctl
- fix race when finishing block group creation
- remove link to obsolete wiki in several files
* tag 'for-6.6-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
MAINTAINERS: remove links to obsolete btrfs.wiki.kernel.org
btrfs: assert delayed node locked when removing delayed item
btrfs: remove BUG() after failure to insert delayed dir index item
btrfs: improve error message after failure to add delayed dir index item
btrfs: fix a compilation error if DEBUG is defined in btree_dirty_folio
btrfs: check for BTRFS_FS_ERROR in pending ordered assert
btrfs: fix lockdep splat and potential deadlock after failure running delayed items
btrfs: do not block starts waiting on previous transaction commit
btrfs: release path before inode lookup during the ino lookup ioctl
btrfs: fix race between finishing block group creation and its item update
The wiki has been archived and is not updated anymore. Remove or replace
the links in files that contain it (MAINTAINERS, Kconfig, docs).
Signed-off-by: Bhaskar Chowdhury <unixbhaskar@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When removing a delayed item, or releasing which will remove it as well,
we will modify one of the delayed node's rbtrees and item counter if the
delayed item is in one of the rbtrees. This require having the delayed
node's mutex locked, otherwise we will race with other tasks modifying
the rbtrees and the counter.
This is motivated by a previous version of another patch actually calling
btrfs_release_delayed_item() after unlocking the delayed node's mutex and
against a delayed item that is in a rbtree.
So assert at __btrfs_remove_delayed_item() that the delayed node's mutex
is locked.
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Instead of calling BUG() when we fail to insert a delayed dir index item
into the delayed node's tree, we can just release all the resources we
have allocated/acquired before and return the error to the caller. This is
fine because all existing call chains undo anything they have done before
calling btrfs_insert_delayed_dir_index() or BUG_ON (when creating pending
snapshots in the transaction commit path).
So remove the BUG() call and do proper error handling.
This relates to a syzbot report linked below, but does not fix it because
it only prevents hitting a BUG(), it does not fix the issue where somehow
we attempt to use twice the same index number for different index items.
Link: https://lore.kernel.org/linux-btrfs/00000000000036e1290603e097e0@google.com/
CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
If we fail to add a delayed dir index item because there's already another
item with the same index number, we print an error message (and then BUG).
However that message isn't very helpful to debug anything because we don't
know what's the index number and what are the values of index counters in
the inode and its delayed inode (index_cnt fields of struct btrfs_inode
and struct btrfs_delayed_node).
So update the error message to include the index number and counters.
We actually had a recent case where this issue was hit by a syzbot report
(see the link below).
Link: https://lore.kernel.org/linux-btrfs/00000000000036e1290603e097e0@google.com/
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
[BUG]
After commit 72a69cd030 ("btrfs: subpage: pack all subpage bitmaps
into a larger bitmap"), the DEBUG section of btree_dirty_folio() would
no longer compile.
[CAUSE]
If DEBUG is defined, we would do extra checks for btree_dirty_folio(),
mostly to make sure the range we marked dirty has an extent buffer and
that extent buffer is dirty.
For subpage, we need to iterate through all the extent buffers covered
by that page range, and make sure they all matches the criteria.
However commit 72a69cd030 ("btrfs: subpage: pack all subpage bitmaps
into a larger bitmap") changes how we store the bitmap, we pack all the
16 bits bitmaps into a larger bitmap, which would save some space.
This means we no longer have btrfs_subpage::dirty_bitmap, instead the
dirty bitmap is starting at btrfs_subpage_info::dirty_offset, and has a
length of btrfs_subpage_info::bitmap_nr_bits.
[FIX]
Although I'm not sure if it still makes sense to maintain such code, at
least let it compile.
This patch would let us test the bits one by one through the bitmaps.
CC: stable@vger.kernel.org # 6.1+
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
If we do fast tree logging we increment a counter on the current
transaction for every ordered extent we need to wait for. This means we
expect the transaction to still be there when we clear pending on the
ordered extent. However if we happen to abort the transaction and clean
it up, there could be no running transaction, and thus we'll trip the
"ASSERT(trans)" check. This is obviously incorrect, and the code
properly deals with the case that the transaction doesn't exist. Fix
this ASSERT() to only fire if there's no trans and we don't have
BTRFS_FS_ERROR() set on the file system.
CC: stable@vger.kernel.org # 4.14+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Internally I got a report of very long stalls on normal operations like
creating a new file when auto relocation was running. The reporter used
the 'bpf offcputime' tracer to show that we would get stuck in
start_transaction for 5 to 30 seconds, and were always being woken up by
the transaction commit.
Using my timing-everything script, which times how long a function takes
and what percentage of that total time is taken up by its children, I
saw several traces like this
1083 took 32812902424 ns
29929002926 ns 91.2110% wait_for_commit_duration
25568 ns 7.7920e-05% commit_fs_roots_duration
1007751 ns 0.00307% commit_cowonly_roots_duration
446855602 ns 1.36182% btrfs_run_delayed_refs_duration
271980 ns 0.00082% btrfs_run_delayed_items_duration
2008 ns 6.1195e-06% btrfs_apply_pending_changes_duration
9656 ns 2.9427e-05% switch_commit_roots_duration
1598 ns 4.8700e-06% btrfs_commit_device_sizes_duration
4314 ns 1.3147e-05% btrfs_free_log_root_tree_duration
Here I was only tracing functions that happen where we are between
START_COMMIT and UNBLOCKED in order to see what would be keeping us
blocked for so long. The wait_for_commit() we do is where we wait for a
previous transaction that hasn't completed it's commit. This can
include all of the unpin work and other cleanups, which tends to be the
longest part of our transaction commit.
There is no reason we should be blocking new things from entering the
transaction at this point, it just adds to random latency spikes for no
reason.
Fix this by adding a PREP stage. This allows us to properly deal with
multiple committers coming in at the same time, we retain the behavior
that the winner waits on the previous transaction and the losers all
wait for this transaction commit to occur. Nothing else is blocked
during the PREP stage, and then once the wait is complete we switch to
COMMIT_START and all of the same behavior as before is maintained.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
During the ino lookup ioctl we can end up calling btrfs_iget() to get an
inode reference while we are holding on a root's btree. If btrfs_iget()
needs to lookup the inode from the root's btree, because it's not
currently loaded in memory, then it will need to lock another or the
same path in the same root btree. This may result in a deadlock and
trigger the following lockdep splat:
WARNING: possible circular locking dependency detected
6.5.0-rc7-syzkaller-00004-gf7757129e3de #0 Not tainted
------------------------------------------------------
syz-executor277/5012 is trying to acquire lock:
ffff88802df41710 (btrfs-tree-01){++++}-{3:3}, at: __btrfs_tree_read_lock+0x2f/0x220 fs/btrfs/locking.c:136
but task is already holding lock:
ffff88802df418e8 (btrfs-tree-00){++++}-{3:3}, at: __btrfs_tree_read_lock+0x2f/0x220 fs/btrfs/locking.c:136
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (btrfs-tree-00){++++}-{3:3}:
down_read_nested+0x49/0x2f0 kernel/locking/rwsem.c:1645
__btrfs_tree_read_lock+0x2f/0x220 fs/btrfs/locking.c:136
btrfs_search_slot+0x13a4/0x2f80 fs/btrfs/ctree.c:2302
btrfs_init_root_free_objectid+0x148/0x320 fs/btrfs/disk-io.c:4955
btrfs_init_fs_root fs/btrfs/disk-io.c:1128 [inline]
btrfs_get_root_ref+0x5ae/0xae0 fs/btrfs/disk-io.c:1338
btrfs_get_fs_root fs/btrfs/disk-io.c:1390 [inline]
open_ctree+0x29c8/0x3030 fs/btrfs/disk-io.c:3494
btrfs_fill_super+0x1c7/0x2f0 fs/btrfs/super.c:1154
btrfs_mount_root+0x7e0/0x910 fs/btrfs/super.c:1519
legacy_get_tree+0xef/0x190 fs/fs_context.c:611
vfs_get_tree+0x8c/0x270 fs/super.c:1519
fc_mount fs/namespace.c:1112 [inline]
vfs_kern_mount+0xbc/0x150 fs/namespace.c:1142
btrfs_mount+0x39f/0xb50 fs/btrfs/super.c:1579
legacy_get_tree+0xef/0x190 fs/fs_context.c:611
vfs_get_tree+0x8c/0x270 fs/super.c:1519
do_new_mount+0x28f/0xae0 fs/namespace.c:3335
do_mount fs/namespace.c:3675 [inline]
__do_sys_mount fs/namespace.c:3884 [inline]
__se_sys_mount+0x2d9/0x3c0 fs/namespace.c:3861
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
-> #0 (btrfs-tree-01){++++}-{3:3}:
check_prev_add kernel/locking/lockdep.c:3142 [inline]
check_prevs_add kernel/locking/lockdep.c:3261 [inline]
validate_chain kernel/locking/lockdep.c:3876 [inline]
__lock_acquire+0x39ff/0x7f70 kernel/locking/lockdep.c:5144
lock_acquire+0x1e3/0x520 kernel/locking/lockdep.c:5761
down_read_nested+0x49/0x2f0 kernel/locking/rwsem.c:1645
__btrfs_tree_read_lock+0x2f/0x220 fs/btrfs/locking.c:136
btrfs_tree_read_lock fs/btrfs/locking.c:142 [inline]
btrfs_read_lock_root_node+0x292/0x3c0 fs/btrfs/locking.c:281
btrfs_search_slot_get_root fs/btrfs/ctree.c:1832 [inline]
btrfs_search_slot+0x4ff/0x2f80 fs/btrfs/ctree.c:2154
btrfs_lookup_inode+0xdc/0x480 fs/btrfs/inode-item.c:412
btrfs_read_locked_inode fs/btrfs/inode.c:3892 [inline]
btrfs_iget_path+0x2d9/0x1520 fs/btrfs/inode.c:5716
btrfs_search_path_in_tree_user fs/btrfs/ioctl.c:1961 [inline]
btrfs_ioctl_ino_lookup_user+0x77a/0xf50 fs/btrfs/ioctl.c:2105
btrfs_ioctl+0xb0b/0xd40 fs/btrfs/ioctl.c:4683
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:870 [inline]
__se_sys_ioctl+0xf8/0x170 fs/ioctl.c:856
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
rlock(btrfs-tree-00);
lock(btrfs-tree-01);
lock(btrfs-tree-00);
rlock(btrfs-tree-01);
*** DEADLOCK ***
1 lock held by syz-executor277/5012:
#0: ffff88802df418e8 (btrfs-tree-00){++++}-{3:3}, at: __btrfs_tree_read_lock+0x2f/0x220 fs/btrfs/locking.c:136
stack backtrace:
CPU: 1 PID: 5012 Comm: syz-executor277 Not tainted 6.5.0-rc7-syzkaller-00004-gf7757129e3de #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106
check_noncircular+0x375/0x4a0 kernel/locking/lockdep.c:2195
check_prev_add kernel/locking/lockdep.c:3142 [inline]
check_prevs_add kernel/locking/lockdep.c:3261 [inline]
validate_chain kernel/locking/lockdep.c:3876 [inline]
__lock_acquire+0x39ff/0x7f70 kernel/locking/lockdep.c:5144
lock_acquire+0x1e3/0x520 kernel/locking/lockdep.c:5761
down_read_nested+0x49/0x2f0 kernel/locking/rwsem.c:1645
__btrfs_tree_read_lock+0x2f/0x220 fs/btrfs/locking.c:136
btrfs_tree_read_lock fs/btrfs/locking.c:142 [inline]
btrfs_read_lock_root_node+0x292/0x3c0 fs/btrfs/locking.c:281
btrfs_search_slot_get_root fs/btrfs/ctree.c:1832 [inline]
btrfs_search_slot+0x4ff/0x2f80 fs/btrfs/ctree.c:2154
btrfs_lookup_inode+0xdc/0x480 fs/btrfs/inode-item.c:412
btrfs_read_locked_inode fs/btrfs/inode.c:3892 [inline]
btrfs_iget_path+0x2d9/0x1520 fs/btrfs/inode.c:5716
btrfs_search_path_in_tree_user fs/btrfs/ioctl.c:1961 [inline]
btrfs_ioctl_ino_lookup_user+0x77a/0xf50 fs/btrfs/ioctl.c:2105
btrfs_ioctl+0xb0b/0xd40 fs/btrfs/ioctl.c:4683
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:870 [inline]
__se_sys_ioctl+0xf8/0x170 fs/ioctl.c:856
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f0bec94ea39
Fix this simply by releasing the path before calling btrfs_iget() as at
point we don't need the path anymore.
Reported-by: syzbot+bf66ad948981797d2f1d@syzkaller.appspotmail.com
Link: https://lore.kernel.org/linux-btrfs/00000000000045fa140603c4a969@google.com/
Fixes: 23d0b79dfa ("btrfs: Add unprivileged version of ino_lookup ioctl")
CC: stable@vger.kernel.org # 4.19+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
