History log of /openbmc/linux/fs/btrfs/ctree.h (Results 1 – 25 of 4265)
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Revision tags: v6.6.71
# 9144f784 09-Jan-2025 Andrew Jeffery <andrew@codeconstruct.com.au>

Merge tag 'v6.6.70' into for/openbmc/dev-6.6

This is the 6.6.70 stable release

Conflicts:
include/linux/usb/chipidea.h

Conflict was a trivial addition.

Signed-off-by: Andrew Jeffery <andrew@c

Merge tag 'v6.6.70' into for/openbmc/dev-6.6

This is the 6.6.70 stable release

Conflicts:
include/linux/usb/chipidea.h

Conflict was a trivial addition.

Signed-off-by: Andrew Jeffery <andrew@codeconstruct.com.au>

show more ...


Revision tags: v6.6.70, v6.6.69, v6.6.68, v6.6.67, v6.6.66, v6.6.65, v6.6.64, v6.6.63, v6.6.62, v6.6.61, v6.6.60, v6.6.59, v6.6.58, v6.6.57, v6.6.56, v6.6.55, v6.6.54, v6.6.53, v6.6.52, v6.6.51, v6.6.50, v6.6.49, v6.6.48, v6.6.47, v6.6.46, v6.6.45, v6.6.44, v6.6.43, v6.6.42, v6.6.41, v6.6.40, v6.6.39, v6.6.38, v6.6.37, v6.6.36, v6.6.35, v6.6.34, v6.6.33, v6.6.32, v6.6.31, v6.6.30, v6.6.29, v6.6.28, v6.6.27, v6.6.26, v6.6.25, v6.6.24, v6.6.23, v6.6.16, v6.6.15, v6.6.14, v6.6.13, v6.6.12, v6.6.11, v6.6.10, v6.6.9, v6.6.8, v6.6.7, v6.6.6, v6.6.5, v6.6.4, v6.6.3, v6.6.2, v6.5.11, v6.6.1, v6.5.10, v6.6, v6.5.9, v6.5.8, v6.5.7, v6.5.6
# 0d2cc60b 27-Sep-2023 Filipe Manana <fdmanana@suse.com>

btrfs: rename and export __btrfs_cow_block()

[ Upstream commit 95f93bc4cbcac6121a5ee85cd5019ee8e7447e0b ]

Rename and export __btrfs_cow_block() as btrfs_force_cow_block(). This is
to allow to move

btrfs: rename and export __btrfs_cow_block()

[ Upstream commit 95f93bc4cbcac6121a5ee85cd5019ee8e7447e0b ]

Rename and export __btrfs_cow_block() as btrfs_force_cow_block(). This is
to allow to move defrag specific code out of ctree.c and into defrag.c in
one of the next patches.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Stable-dep-of: 44f52bbe96df ("btrfs: fix use-after-free when COWing tree bock and tracing is enabled")
Signed-off-by: Sasha Levin <sashal@kernel.org>

show more ...


# 34d6f206 07-Oct-2024 Andrew Jeffery <andrew@codeconstruct.com.au>

Merge tag 'v6.6.54' into for/openbmc/dev-6.6

This is the 6.6.54 stable release


# f56a6d9c 03-Sep-2024 Filipe Manana <fdmanana@suse.com>

btrfs: fix race setting file private on concurrent lseek using same fd

[ Upstream commit 7ee85f5515e86a4e2a2f51969795920733912bad ]

When doing concurrent lseek(2) system calls against the same file

btrfs: fix race setting file private on concurrent lseek using same fd

[ Upstream commit 7ee85f5515e86a4e2a2f51969795920733912bad ]

When doing concurrent lseek(2) system calls against the same file
descriptor, using multiple threads belonging to the same process, we have
a short time window where a race happens and can result in a memory leak.

The race happens like this:

1) A program opens a file descriptor for a file and then spawns two
threads (with the pthreads library for example), lets call them
task A and task B;

2) Task A calls lseek with SEEK_DATA or SEEK_HOLE and ends up at
file.c:find_desired_extent() while holding a read lock on the inode;

3) At the start of find_desired_extent(), it extracts the file's
private_data pointer into a local variable named 'private', which has
a value of NULL;

4) Task B also calls lseek with SEEK_DATA or SEEK_HOLE, locks the inode
in shared mode and enters file.c:find_desired_extent(), where it also
extracts file->private_data into its local variable 'private', which
has a NULL value;

5) Because it saw a NULL file private, task A allocates a private
structure and assigns to the file structure;

6) Task B also saw a NULL file private so it also allocates its own file
private and then assigns it to the same file structure, since both
tasks are using the same file descriptor.

At this point we leak the private structure allocated by task A.

Besides the memory leak, there's also the detail that both tasks end up
using the same cached state record in the private structure (struct
btrfs_file_private::llseek_cached_state), which can result in a
use-after-free problem since one task can free it while the other is
still using it (only one task took a reference count on it). Also, sharing
the cached state is not a good idea since it could result in incorrect
results in the future - right now it should not be a problem because it
end ups being used only in extent-io-tree.c:count_range_bits() where we do
range validation before using the cached state.

Fix this by protecting the private assignment and check of a file while
holding the inode's spinlock and keep track of the task that allocated
the private, so that it's used only by that task in order to prevent
user-after-free issues with the cached state record as well as potentially
using it incorrectly in the future.

Fixes: 3c32c7212f16 ("btrfs: use cached state when looking for delalloc ranges with lseek")
CC: stable@vger.kernel.org # 6.6+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

show more ...


# ca2478a7 12-Sep-2024 Andrew Jeffery <andrew@codeconstruct.com.au>

Merge tag 'v6.6.51' into for/openbmc/dev-6.6

This is the 6.6.51 stable release


# 7b5595f3 29-Aug-2024 Filipe Manana <fdmanana@suse.com>

btrfs: fix race between direct IO write and fsync when using same fd

commit cd9253c23aedd61eb5ff11f37a36247cd46faf86 upstream.

If we have 2 threads that are using the same file descriptor and one o

btrfs: fix race between direct IO write and fsync when using same fd

commit cd9253c23aedd61eb5ff11f37a36247cd46faf86 upstream.

If we have 2 threads that are using the same file descriptor and one of
them is doing direct IO writes while the other is doing fsync, we have a
race where we can end up either:

1) Attempt a fsync without holding the inode's lock, triggering an
assertion failures when assertions are enabled;

2) Do an invalid memory access from the fsync task because the file private
points to memory allocated on stack by the direct IO task and it may be
used by the fsync task after the stack was destroyed.

The race happens like this:

1) A user space program opens a file descriptor with O_DIRECT;

2) The program spawns 2 threads using libpthread for example;

3) One of the threads uses the file descriptor to do direct IO writes,
while the other calls fsync using the same file descriptor.

4) Call task A the thread doing direct IO writes and task B the thread
doing fsyncs;

5) Task A does a direct IO write, and at btrfs_direct_write() sets the
file's private to an on stack allocated private with the member
'fsync_skip_inode_lock' set to true;

6) Task B enters btrfs_sync_file() and sees that there's a private
structure associated to the file which has 'fsync_skip_inode_lock' set
to true, so it skips locking the inode's VFS lock;

7) Task A completes the direct IO write, and resets the file's private to
NULL since it had no prior private and our private was stack allocated.
Then it unlocks the inode's VFS lock;

8) Task B enters btrfs_get_ordered_extents_for_logging(), then the
assertion that checks the inode's VFS lock is held fails, since task B
never locked it and task A has already unlocked it.

The stack trace produced is the following:

assertion failed: inode_is_locked(&inode->vfs_inode), in fs/btrfs/ordered-data.c:983
------------[ cut here ]------------
kernel BUG at fs/btrfs/ordered-data.c:983!
Oops: invalid opcode: 0000 [#1] PREEMPT SMP PTI
CPU: 9 PID: 5072 Comm: worker Tainted: G U OE 6.10.5-1-default #1 openSUSE Tumbleweed 69f48d427608e1c09e60ea24c6c55e2ca1b049e8
Hardware name: Acer Predator PH315-52/Covini_CFS, BIOS V1.12 07/28/2020
RIP: 0010:btrfs_get_ordered_extents_for_logging.cold+0x1f/0x42 [btrfs]
Code: 50 d6 86 c0 e8 (...)
RSP: 0018:ffff9e4a03dcfc78 EFLAGS: 00010246
RAX: 0000000000000054 RBX: ffff9078a9868e98 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffff907dce4a7800 RDI: ffff907dce4a7800
RBP: ffff907805518800 R08: 0000000000000000 R09: ffff9e4a03dcfb38
R10: ffff9e4a03dcfb30 R11: 0000000000000003 R12: ffff907684ae7800
R13: 0000000000000001 R14: ffff90774646b600 R15: 0000000000000000
FS: 00007f04b96006c0(0000) GS:ffff907dce480000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f32acbfc000 CR3: 00000001fd4fa005 CR4: 00000000003726f0
Call Trace:
<TASK>
? __die_body.cold+0x14/0x24
? die+0x2e/0x50
? do_trap+0xca/0x110
? do_error_trap+0x6a/0x90
? btrfs_get_ordered_extents_for_logging.cold+0x1f/0x42 [btrfs bb26272d49b4cdc847cf3f7faadd459b62caee9a]
? exc_invalid_op+0x50/0x70
? btrfs_get_ordered_extents_for_logging.cold+0x1f/0x42 [btrfs bb26272d49b4cdc847cf3f7faadd459b62caee9a]
? asm_exc_invalid_op+0x1a/0x20
? btrfs_get_ordered_extents_for_logging.cold+0x1f/0x42 [btrfs bb26272d49b4cdc847cf3f7faadd459b62caee9a]
? btrfs_get_ordered_extents_for_logging.cold+0x1f/0x42 [btrfs bb26272d49b4cdc847cf3f7faadd459b62caee9a]
btrfs_sync_file+0x21a/0x4d0 [btrfs bb26272d49b4cdc847cf3f7faadd459b62caee9a]
? __seccomp_filter+0x31d/0x4f0
__x64_sys_fdatasync+0x4f/0x90
do_syscall_64+0x82/0x160
? do_futex+0xcb/0x190
? __x64_sys_futex+0x10e/0x1d0
? switch_fpu_return+0x4f/0xd0
? syscall_exit_to_user_mode+0x72/0x220
? do_syscall_64+0x8e/0x160
? syscall_exit_to_user_mode+0x72/0x220
? do_syscall_64+0x8e/0x160
? syscall_exit_to_user_mode+0x72/0x220
? do_syscall_64+0x8e/0x160
? syscall_exit_to_user_mode+0x72/0x220
? do_syscall_64+0x8e/0x160
entry_SYSCALL_64_after_hwframe+0x76/0x7e

Another problem here is if task B grabs the private pointer and then uses
it after task A has finished, since the private was allocated in the stack
of task A, it results in some invalid memory access with a hard to predict
result.

This issue, triggering the assertion, was observed with QEMU workloads by
two users in the Link tags below.

Fix this by not relying on a file's private to pass information to fsync
that it should skip locking the inode and instead pass this information
through a special value stored in current->journal_info. This is safe
because in the relevant section of the direct IO write path we are not
holding a transaction handle, so current->journal_info is NULL.

The following C program triggers the issue:

$ cat repro.c
/* Get the O_DIRECT definition. */
#ifndef _GNU_SOURCE
#define _GNU_SOURCE
#endif

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <stdint.h>
#include <fcntl.h>
#include <errno.h>
#include <string.h>
#include <pthread.h>

static int fd;

static ssize_t do_write(int fd, const void *buf, size_t count, off_t offset)
{
while (count > 0) {
ssize_t ret;

ret = pwrite(fd, buf, count, offset);
if (ret < 0) {
if (errno == EINTR)
continue;
return ret;
}
count -= ret;
buf += ret;
}
return 0;
}

static void *fsync_loop(void *arg)
{
while (1) {
int ret;

ret = fsync(fd);
if (ret != 0) {
perror("Fsync failed");
exit(6);
}
}
}

int main(int argc, char *argv[])
{
long pagesize;
void *write_buf;
pthread_t fsyncer;
int ret;

if (argc != 2) {
fprintf(stderr, "Use: %s <file path>\n", argv[0]);
return 1;
}

fd = open(argv[1], O_WRONLY | O_CREAT | O_TRUNC | O_DIRECT, 0666);
if (fd == -1) {
perror("Failed to open/create file");
return 1;
}

pagesize = sysconf(_SC_PAGE_SIZE);
if (pagesize == -1) {
perror("Failed to get page size");
return 2;
}

ret = posix_memalign(&write_buf, pagesize, pagesize);
if (ret) {
perror("Failed to allocate buffer");
return 3;
}

ret = pthread_create(&fsyncer, NULL, fsync_loop, NULL);
if (ret != 0) {
fprintf(stderr, "Failed to create writer thread: %d\n", ret);
return 4;
}

while (1) {
ret = do_write(fd, write_buf, pagesize, 0);
if (ret != 0) {
perror("Write failed");
exit(5);
}
}

return 0;
}

$ mkfs.btrfs -f /dev/sdi
$ mount /dev/sdi /mnt/sdi
$ timeout 10 ./repro /mnt/sdi/foo

Usually the race is triggered within less than 1 second. A test case for
fstests will follow soon.

Reported-by: Paulo Dias <paulo.miguel.dias@gmail.com>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=219187
Reported-by: Andreas Jahn <jahn-andi@web.de>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=219199
Reported-by: syzbot+4704b3cc972bd76024f1@syzkaller.appspotmail.com
Link: https://lore.kernel.org/linux-btrfs/00000000000044ff540620d7dee2@google.com/
Fixes: 939b656bc8ab ("btrfs: fix corruption after buffer fault in during direct IO append write")
CC: stable@vger.kernel.org # 5.15+
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...


# c005e2f6 14-Aug-2024 Andrew Jeffery <andrew@codeconstruct.com.au>

Merge tag 'v6.6.46' into for/openbmc/dev-6.6

This is the 6.6.46 stable release


# 0a108bde 26-Jul-2024 Filipe Manana <fdmanana@suse.com>

btrfs: fix corruption after buffer fault in during direct IO append write

commit 939b656bc8ab203fdbde26ccac22bcb7f0985be5 upstream.

During an append (O_APPEND write flag) direct IO write if the inp

btrfs: fix corruption after buffer fault in during direct IO append write

commit 939b656bc8ab203fdbde26ccac22bcb7f0985be5 upstream.

During an append (O_APPEND write flag) direct IO write if the input buffer
was not previously faulted in, we can corrupt the file in a way that the
final size is unexpected and it includes an unexpected hole.

The problem happens like this:

1) We have an empty file, with size 0, for example;

2) We do an O_APPEND direct IO with a length of 4096 bytes and the input
buffer is not currently faulted in;

3) We enter btrfs_direct_write(), lock the inode and call
generic_write_checks(), which calls generic_write_checks_count(), and
that function sets the iocb position to 0 with the following code:

if (iocb->ki_flags & IOCB_APPEND)
iocb->ki_pos = i_size_read(inode);

4) We call btrfs_dio_write() and enter into iomap, which will end up
calling btrfs_dio_iomap_begin() and that calls
btrfs_get_blocks_direct_write(), where we update the i_size of the
inode to 4096 bytes;

5) After btrfs_dio_iomap_begin() returns, iomap will attempt to access
the page of the write input buffer (at iomap_dio_bio_iter(), with a
call to bio_iov_iter_get_pages()) and fail with -EFAULT, which gets
returned to btrfs at btrfs_direct_write() via btrfs_dio_write();

6) At btrfs_direct_write() we get the -EFAULT error, unlock the inode,
fault in the write buffer and then goto to the label 'relock';

7) We lock again the inode, do all the necessary checks again and call
again generic_write_checks(), which calls generic_write_checks_count()
again, and there we set the iocb's position to 4K, which is the current
i_size of the inode, with the following code pointed above:

if (iocb->ki_flags & IOCB_APPEND)
iocb->ki_pos = i_size_read(inode);

8) Then we go again to btrfs_dio_write() and enter iomap and the write
succeeds, but it wrote to the file range [4K, 8K), leaving a hole in
the [0, 4K) range and an i_size of 8K, which goes against the
expectations of having the data written to the range [0, 4K) and get an
i_size of 4K.

Fix this by not unlocking the inode before faulting in the input buffer,
in case we get -EFAULT or an incomplete write, and not jumping to the
'relock' label after faulting in the buffer - instead jump to a location
immediately before calling iomap, skipping all the write checks and
relocking. This solves this problem and it's fine even in case the input
buffer is memory mapped to the same file range, since only holding the
range locked in the inode's io tree can cause a deadlock, it's safe to
keep the inode lock (VFS lock), as was fixed and described in commit
51bd9563b678 ("btrfs: fix deadlock due to page faults during direct IO
reads and writes").

A sample reproducer provided by a reporter is the following:

$ cat test.c
#ifndef _GNU_SOURCE
#define _GNU_SOURCE
#endif

#include <fcntl.h>
#include <stdio.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <unistd.h>

int main(int argc, char *argv[])
{
if (argc < 2) {
fprintf(stderr, "Usage: %s <test file>\n", argv[0]);
return 1;
}

int fd = open(argv[1], O_WRONLY | O_CREAT | O_TRUNC | O_DIRECT |
O_APPEND, 0644);
if (fd < 0) {
perror("creating test file");
return 1;
}

char *buf = mmap(NULL, 4096, PROT_READ,
MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
ssize_t ret = write(fd, buf, 4096);
if (ret < 0) {
perror("pwritev2");
return 1;
}

struct stat stbuf;
ret = fstat(fd, &stbuf);
if (ret < 0) {
perror("stat");
return 1;
}

printf("size: %llu\n", (unsigned long long)stbuf.st_size);
return stbuf.st_size == 4096 ? 0 : 1;
}

A test case for fstests will be sent soon.

Reported-by: Hanna Czenczek <hreitz@redhat.com>
Link: https://lore.kernel.org/linux-btrfs/0b841d46-12fe-4e64-9abb-871d8d0de271@redhat.com/
Fixes: 8184620ae212 ("btrfs: fix lost file sync on direct IO write with nowait and dsync iocb")
CC: stable@vger.kernel.org # 6.1+
Tested-by: Hanna Czenczek <hreitz@redhat.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...


# b97d6790 13-Dec-2023 Joel Stanley <joel@jms.id.au>

Merge tag 'v6.6.6' into dev-6.6

This is the 6.6.6 stable release

Signed-off-by: Joel Stanley <joel@jms.id.au>


Revision tags: v6.5.5, v6.5.4, v6.5.3
# d5e09e38 12-Sep-2023 Filipe Manana <fdmanana@suse.com>

btrfs: abort transaction on generation mismatch when marking eb as dirty

[ Upstream commit 50564b651d01c19ce732819c5b3c3fd60707188e ]

When marking an extent buffer as dirty, at btrfs_mark_buffer_di

btrfs: abort transaction on generation mismatch when marking eb as dirty

[ Upstream commit 50564b651d01c19ce732819c5b3c3fd60707188e ]

When marking an extent buffer as dirty, at btrfs_mark_buffer_dirty(),
we check if its generation matches the running transaction and if not we
just print a warning. Such mismatch is an indicator that something really
went wrong and only printing a warning message (and stack trace) is not
enough to prevent a corruption. Allowing a transaction to commit with such
an extent buffer will trigger an error if we ever try to read it from disk
due to a generation mismatch with its parent generation.

So abort the current transaction with -EUCLEAN if we notice a generation
mismatch. For this we need to pass a transaction handle to
btrfs_mark_buffer_dirty() which is always available except in test code,
in which case we can pass NULL since it operates on dummy extent buffers
and all test roots have a single node/leaf (root node at level 0).

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

show more ...


# e017769f 23-Oct-2023 Linus Torvalds <torvalds@linux-foundation.org>

Merge tag 'for-6.6-rc7-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs fix from David Sterba:
"One more fix for a problem with snapshot of a newly created subvolume
t

Merge tag 'for-6.6-rc7-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs fix from David Sterba:
"One more fix for a problem with snapshot of a newly created subvolume
that can lead to inconsistent data under some circumstances. Kernel
6.5 added a performance optimization to skip transaction commit for
subvolume creation but this could end up with newer data on disk but
not linked to other structures.

The fix itself is an added condition, the rest of the patch is a
parameter added to several functions"

* tag 'for-6.6-rc7-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: fix unwritten extent buffer after snapshotting a new subvolume

show more ...


# eb96e221 19-Oct-2023 Filipe Manana <fdmanana@suse.com>

btrfs: fix unwritten extent buffer after snapshotting a new subvolume

When creating a snapshot of a subvolume that was created in the current
transaction, we can end up not persisting a dirty extent

btrfs: fix unwritten extent buffer after snapshotting a new subvolume

When creating a snapshot of a subvolume that was created in the current
transaction, we can end up not persisting a dirty extent buffer that is
referenced by the snapshot, resulting in IO errors due to checksum failures
when trying to read the extent buffer later from disk. A sequence of steps
that leads to this is the following:

1) At ioctl.c:create_subvol() we allocate an extent buffer, with logical
address 36007936, for the leaf/root of a new subvolume that has an ID
of 291. We mark the extent buffer as dirty, and at this point the
subvolume tree has a single node/leaf which is also its root (level 0);

2) We no longer commit the transaction used to create the subvolume at
create_subvol(). We used to, but that was recently removed in
commit 1b53e51a4a8f ("btrfs: don't commit transaction for every subvol
create");

3) The transaction used to create the subvolume has an ID of 33, so the
extent buffer 36007936 has a generation of 33;

4) Several updates happen to subvolume 291 during transaction 33, several
files created and its tree height changes from 0 to 1, so we end up with
a new root at level 1 and the extent buffer 36007936 is now a leaf of
that new root node, which is extent buffer 36048896.

The commit root remains as 36007936, since we are still at transaction
33;

5) Creation of a snapshot of subvolume 291, with an ID of 292, starts at
ioctl.c:create_snapshot(). This triggers a commit of transaction 33 and
we end up at transaction.c:create_pending_snapshot(), in the critical
section of a transaction commit.

There we COW the root of subvolume 291, which is extent buffer 36048896.
The COW operation returns extent buffer 36048896, since there's no need
to COW because the extent buffer was created in this transaction and it
was not written yet.

The we call btrfs_copy_root() against the root node 36048896. During
this operation we allocate a new extent buffer to turn into the root
node of the snapshot, copy the contents of the root node 36048896 into
this snapshot root extent buffer, set the owner to 292 (the ID of the
snapshot), etc, and then we call btrfs_inc_ref(). This will create a
delayed reference for each leaf pointed by the root node with a
reference root of 292 - this includes a reference for the leaf
36007936.

After that we set the bit BTRFS_ROOT_FORCE_COW in the root's state.

Then we call btrfs_insert_dir_item(), to create the directory entry in
in the tree of subvolume 291 that points to the snapshot. This ends up
needing to modify leaf 36007936 to insert the respective directory
items. Because the bit BTRFS_ROOT_FORCE_COW is set for the root's state,
we need to COW the leaf. We end up at btrfs_force_cow_block() and then
at update_ref_for_cow().

At update_ref_for_cow() we call btrfs_block_can_be_shared() which
returns false, despite the fact the leaf 36007936 is shared - the
subvolume's root and the snapshot's root point to that leaf. The
reason that it incorrectly returns false is because the commit root
of the subvolume is extent buffer 36007936 - it was the initial root
of the subvolume when we created it. So btrfs_block_can_be_shared()
which has the following logic:

int btrfs_block_can_be_shared(struct btrfs_root *root,
struct extent_buffer *buf)
{
if (test_bit(BTRFS_ROOT_SHAREABLE, &root->state) &&
buf != root->node && buf != root->commit_root &&
(btrfs_header_generation(buf) <=
btrfs_root_last_snapshot(&root->root_item) ||
btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC)))
return 1;

return 0;
}

Returns false (0) since 'buf' (extent buffer 36007936) matches the
root's commit root.

As a result, at update_ref_for_cow(), we don't check for the number
of references for extent buffer 36007936, we just assume it's not
shared and therefore that it has only 1 reference, so we set the local
variable 'refs' to 1.

Later on, in the final if-else statement at update_ref_for_cow():

static noinline int update_ref_for_cow(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct extent_buffer *buf,
struct extent_buffer *cow,
int *last_ref)
{
(...)
if (refs > 1) {
(...)
} else {
(...)
btrfs_clear_buffer_dirty(trans, buf);
*last_ref = 1;
}
}

So we mark the extent buffer 36007936 as not dirty, and as a result
we don't write it to disk later in the transaction commit, despite the
fact that the snapshot's root points to it.

Attempting to access the leaf or dumping the tree for example shows
that the extent buffer was not written:

$ btrfs inspect-internal dump-tree -t 292 /dev/sdb
btrfs-progs v6.2.2
file tree key (292 ROOT_ITEM 33)
node 36110336 level 1 items 2 free space 119 generation 33 owner 292
node 36110336 flags 0x1(WRITTEN) backref revision 1
checksum stored a8103e3e
checksum calced a8103e3e
fs uuid 90c9a46f-ae9f-4626-9aff-0cbf3e2e3a79
chunk uuid e8c9c885-78f4-4d31-85fe-89e5f5fd4a07
key (256 INODE_ITEM 0) block 36007936 gen 33
key (257 EXTENT_DATA 0) block 36052992 gen 33
checksum verify failed on 36007936 wanted 0x00000000 found 0x86005f29
checksum verify failed on 36007936 wanted 0x00000000 found 0x86005f29
total bytes 107374182400
bytes used 38572032
uuid 90c9a46f-ae9f-4626-9aff-0cbf3e2e3a79

The respective on disk region is full of zeroes as the device was
trimmed at mkfs time.

Obviously 'btrfs check' also detects and complains about this:

$ btrfs check /dev/sdb
Opening filesystem to check...
Checking filesystem on /dev/sdb
UUID: 90c9a46f-ae9f-4626-9aff-0cbf3e2e3a79
generation: 33 (33)
[1/7] checking root items
[2/7] checking extents
checksum verify failed on 36007936 wanted 0x00000000 found 0x86005f29
checksum verify failed on 36007936 wanted 0x00000000 found 0x86005f29
checksum verify failed on 36007936 wanted 0x00000000 found 0x86005f29
bad tree block 36007936, bytenr mismatch, want=36007936, have=0
owner ref check failed [36007936 4096]
ERROR: errors found in extent allocation tree or chunk allocation
[3/7] checking free space tree
[4/7] checking fs roots
checksum verify failed on 36007936 wanted 0x00000000 found 0x86005f29
checksum verify failed on 36007936 wanted 0x00000000 found 0x86005f29
checksum verify failed on 36007936 wanted 0x00000000 found 0x86005f29
bad tree block 36007936, bytenr mismatch, want=36007936, have=0
The following tree block(s) is corrupted in tree 292:
tree block bytenr: 36110336, level: 1, node key: (256, 1, 0)
root 292 root dir 256 not found
ERROR: errors found in fs roots
found 38572032 bytes used, error(s) found
total csum bytes: 16048
total tree bytes: 1265664
total fs tree bytes: 1118208
total extent tree bytes: 65536
btree space waste bytes: 562598
file data blocks allocated: 65978368
referenced 36569088

Fix this by updating btrfs_block_can_be_shared() to consider that an
extent buffer may be shared if it matches the commit root and if its
generation matches the current transaction's generation.

This can be reproduced with the following script:

$ cat test.sh
#!/bin/bash

MNT=/mnt/sdi
DEV=/dev/sdi

# Use a filesystem with a 64K node size so that we have the same node
# size on every machine regardless of its page size (on x86_64 default
# node size is 16K due to the 4K page size, while on PPC it's 64K by
# default). This way we can make sure we are able to create a btree for
# the subvolume with a height of 2.
mkfs.btrfs -f -n 64K $DEV
mount $DEV $MNT

btrfs subvolume create $MNT/subvol

# Create a few empty files on the subvolume, this bumps its btree
# height to 2 (root node at level 1 and 2 leaves).
for ((i = 1; i <= 300; i++)); do
echo -n > $MNT/subvol/file_$i
done

btrfs subvolume snapshot -r $MNT/subvol $MNT/subvol/snap

umount $DEV

btrfs check $DEV

Running it on a 6.5 kernel (or any 6.6-rc kernel at the moment):

$ ./test.sh
Create subvolume '/mnt/sdi/subvol'
Create a readonly snapshot of '/mnt/sdi/subvol' in '/mnt/sdi/subvol/snap'
Opening filesystem to check...
Checking filesystem on /dev/sdi
UUID: bbdde2ff-7d02-45ca-8a73-3c36f23755a1
[1/7] checking root items
[2/7] checking extents
parent transid verify failed on 30539776 wanted 7 found 5
parent transid verify failed on 30539776 wanted 7 found 5
parent transid verify failed on 30539776 wanted 7 found 5
Ignoring transid failure
owner ref check failed [30539776 65536]
ERROR: errors found in extent allocation tree or chunk allocation
[3/7] checking free space tree
[4/7] checking fs roots
parent transid verify failed on 30539776 wanted 7 found 5
Ignoring transid failure
Wrong key of child node/leaf, wanted: (256, 1, 0), have: (2, 132, 0)
Wrong generation of child node/leaf, wanted: 5, have: 7
root 257 root dir 256 not found
ERROR: errors found in fs roots
found 917504 bytes used, error(s) found
total csum bytes: 0
total tree bytes: 851968
total fs tree bytes: 393216
total extent tree bytes: 65536
btree space waste bytes: 736550
file data blocks allocated: 0
referenced 0

A test case for fstests will follow soon.

Fixes: 1b53e51a4a8f ("btrfs: don't commit transaction for every subvol create")
CC: stable@vger.kernel.org # 6.5+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

show more ...


# c900529f 12-Sep-2023 Thomas Zimmermann <tzimmermann@suse.de>

Merge drm/drm-fixes into drm-misc-fixes

Forwarding to v6.6-rc1.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>


Revision tags: v6.5.2, v6.1.51, v6.5.1
# 1ac731c5 30-Aug-2023 Dmitry Torokhov <dmitry.torokhov@gmail.com>

Merge branch 'next' into for-linus

Prepare input updates for 6.6 merge window.


Revision tags: v6.1.50, v6.5, v6.1.49, v6.1.48
# 57ce6427 24-Aug-2023 Jakub Kicinski <kuba@kernel.org>

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

Cross-merge networking fixes after downstream PR.

Conflicts:

include/net/inet_sock.h
f866fbc842de ("ipv4: fix data-races around ine

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

Cross-merge networking fixes after downstream PR.

Conflicts:

include/net/inet_sock.h
f866fbc842de ("ipv4: fix data-races around inet->inet_id")
c274af224269 ("inet: introduce inet->inet_flags")
https://lore.kernel.org/all/679ddff6-db6e-4ff6-b177-574e90d0103d@tessares.net/

Adjacent changes:

drivers/net/bonding/bond_alb.c
e74216b8def3 ("bonding: fix macvlan over alb bond support")
f11e5bd159b0 ("bonding: support balance-alb with openvswitch")

drivers/net/ethernet/broadcom/bgmac.c
d6499f0b7c7c ("net: bgmac: Return PTR_ERR() for fixed_phy_register()")
23a14488ea58 ("net: bgmac: Fix return value check for fixed_phy_register()")

drivers/net/ethernet/broadcom/genet/bcmmii.c
32bbe64a1386 ("net: bcmgenet: Fix return value check for fixed_phy_register()")
acf50d1adbf4 ("net: bcmgenet: Return PTR_ERR() for fixed_phy_register()")

net/sctp/socket.c
f866fbc842de ("ipv4: fix data-races around inet->inet_id")
b09bde5c3554 ("inet: move inet->mc_loop to inet->inet_frags")

Signed-off-by: Jakub Kicinski <kuba@kernel.org>

show more ...


# fdebffeb 23-Aug-2023 Dave Airlie <airlied@redhat.com>

BackMerge tag 'v6.5-rc7' into drm-next

Linux 6.5-rc7

This is needed for the CI stuff and the msm pull has fixes in it.

Signed-off-by: Dave Airlie <airlied@redhat.com>


# 642073c3 20-Aug-2023 Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Merge commit b320441c04c9 ("Merge tag 'tty-6.5-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty") into tty-next

We need the serial-core fixes in here as well.

Signed-off-by: Greg Kr

Merge commit b320441c04c9 ("Merge tag 'tty-6.5-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty") into tty-next

We need the serial-core fixes in here as well.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...


# 12e6cced 19-Aug-2023 Linus Torvalds <torvalds@linux-foundation.org>

Merge tag 'for-6.5-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs fixes from David Sterba:

- fix infinite loop in readdir(), could happen in a big directory when

Merge tag 'for-6.5-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs fixes from David Sterba:

- fix infinite loop in readdir(), could happen in a big directory when
files get renamed during enumeration

- fix extent map handling of skipped pinned ranges

- fix a corner case when handling ordered extent length

- fix a potential crash when balance cancel races with pause

- verify correct uuid when starting scrub or device replace

* tag 'for-6.5-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: fix incorrect splitting in btrfs_drop_extent_map_range
btrfs: fix BUG_ON condition in btrfs_cancel_balance
btrfs: only subtract from len_to_oe_boundary when it is tracking an extent
btrfs: fix replace/scrub failure with metadata_uuid
btrfs: fix infinite directory reads

show more ...


Revision tags: v6.1.46
# 9b378f6a 13-Aug-2023 Filipe Manana <fdmanana@suse.com>

btrfs: fix infinite directory reads

The readdir implementation currently processes always up to the last index
it finds. This however can result in an infinite loop if the directory has
a large numb

btrfs: fix infinite directory reads

The readdir implementation currently processes always up to the last index
it finds. This however can result in an infinite loop if the directory has
a large number of entries such that they won't all fit in the given buffer
passed to the readdir callback, that is, dir_emit() returns a non-zero
value. Because in that case readdir() will be called again and if in the
meanwhile new directory entries were added and we still can't put all the
remaining entries in the buffer, we keep repeating this over and over.

The following C program and test script reproduce the problem:

$ cat /mnt/readdir_prog.c
#include <sys/types.h>
#include <dirent.h>
#include <stdio.h>

int main(int argc, char *argv[])
{
DIR *dir = opendir(".");
struct dirent *dd;

while ((dd = readdir(dir))) {
printf("%s\n", dd->d_name);
rename(dd->d_name, "TEMPFILE");
rename("TEMPFILE", dd->d_name);
}
closedir(dir);
}

$ gcc -o /mnt/readdir_prog /mnt/readdir_prog.c

$ cat test.sh
#!/bin/bash

DEV=/dev/sdi
MNT=/mnt/sdi

mkfs.btrfs -f $DEV &> /dev/null
#mkfs.xfs -f $DEV &> /dev/null
#mkfs.ext4 -F $DEV &> /dev/null

mount $DEV $MNT

mkdir $MNT/testdir
for ((i = 1; i <= 2000; i++)); do
echo -n > $MNT/testdir/file_$i
done

cd $MNT/testdir
/mnt/readdir_prog

cd /mnt

umount $MNT

This behaviour is surprising to applications and it's unlike ext4, xfs,
tmpfs, vfat and other filesystems, which always finish. In this case where
new entries were added due to renames, some file names may be reported
more than once, but this varies according to each filesystem - for example
ext4 never reported the same file more than once while xfs reports the
first 13 file names twice.

So change our readdir implementation to track the last index number when
opendir() is called and then make readdir() never process beyond that
index number. This gives the same behaviour as ext4.

Reported-by: Rob Landley <rob@landley.net>
Link: https://lore.kernel.org/linux-btrfs/2c8c55ec-04c6-e0dc-9c5c-8c7924778c35@landley.net/
Link: https://bugzilla.kernel.org/show_bug.cgi?id=217681
CC: stable@vger.kernel.org # 6.4+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

show more ...


Revision tags: v6.1.45, v6.1.44
# 2612e3bb 07-Aug-2023 Rodrigo Vivi <rodrigo.vivi@intel.com>

Merge drm/drm-next into drm-intel-next

Catching-up with drm-next and drm-intel-gt-next.
It will unblock a code refactor around the platform
definitions (names vs acronyms).

Signed-off-by: Rodrigo V

Merge drm/drm-next into drm-intel-next

Catching-up with drm-next and drm-intel-gt-next.
It will unblock a code refactor around the platform
definitions (names vs acronyms).

Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

show more ...


# 9f771739 07-Aug-2023 Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

Merge drm/drm-next into drm-intel-gt-next

Need to pull in b3e4aae612ec ("drm/i915/hdcp: Modify hdcp_gsc_message msg sending mechanism") as
a dependency for https://patchwork.freedesktop.org/series/1

Merge drm/drm-next into drm-intel-gt-next

Need to pull in b3e4aae612ec ("drm/i915/hdcp: Modify hdcp_gsc_message msg sending mechanism") as
a dependency for https://patchwork.freedesktop.org/series/121735/

Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

show more ...


Revision tags: v6.1.43, v6.1.42, v6.1.41
# 61b73694 24-Jul-2023 Thomas Zimmermann <tzimmermann@suse.de>

Merge drm/drm-next into drm-misc-next

Backmerging to get v6.5-rc2.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>


Revision tags: v6.1.40, v6.1.39
# 50501936 17-Jul-2023 Dmitry Torokhov <dmitry.torokhov@gmail.com>

Merge tag 'v6.4' into next

Sync up with mainline to bring in updates to shared infrastructure.


# 0791faeb 17-Jul-2023 Mark Brown <broonie@kernel.org>

ASoC: Merge v6.5-rc2

Get a similar baseline to my other branches, and fixes for people using
the branch.


# 2f98e686 11-Jul-2023 Maxime Ripard <mripard@kernel.org>

Merge v6.5-rc1 into drm-misc-fixes

Boris needs 6.5-rc1 in drm-misc-fixes to prevent a conflict.

Signed-off-by: Maxime Ripard <mripard@kernel.org>


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