diff options
| author | Christoph Hellwig <hch@lst.de> | 2023-06-08 11:10:25 +0200 |
|---|---|---|
| committer | David Sterba <dsterba@suse.com> | 2023-06-13 00:01:00 +0200 |
| commit | 7833b865953c8e62abc76a3261c04132b2fb69de (patch) | |
| tree | 0f6161f5cafb24f8533b990731fa82dda3da481c /fs/btrfs | |
| parent | 79b8ee702c918f1936e17cc53e14bec388ce1045 (diff) | |
btrfs: fix iomap_begin length for nocow writes
can_nocow_extent can reduce the len passed in, which needs to be
propagated to btrfs_dio_iomap_begin so that iomap does not submit
more data then is mapped.
This problems exists since the btrfs_get_blocks_direct helper was added
in commit c5794e51784a ("btrfs: Factor out write portion of
btrfs_get_blocks_direct"), but the ordered_extent splitting added in
commit b73a6fd1b1ef ("btrfs: split partial dio bios before submit")
added a WARN_ON that made a syzkaller test fail.
Reported-by: syzbot+ee90502d5c8fd1d0dd93@syzkaller.appspotmail.com
Fixes: c5794e51784a ("btrfs: Factor out write portion of btrfs_get_blocks_direct")
CC: stable@vger.kernel.org # 6.1+
Tested-by: syzbot+ee90502d5c8fd1d0dd93@syzkaller.appspotmail.com
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'fs/btrfs')
| -rw-r--r-- | fs/btrfs/inode.c | 18 |
1 files changed, 12 insertions, 6 deletions
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 19c707bc8801..3f99f02dc1fe 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -7264,7 +7264,7 @@ static struct extent_map *create_io_em(struct btrfs_inode *inode, u64 start, static int btrfs_get_blocks_direct_write(struct extent_map **map, struct inode *inode, struct btrfs_dio_data *dio_data, - u64 start, u64 len, + u64 start, u64 *lenp, unsigned int iomap_flags) { const bool nowait = (iomap_flags & IOMAP_NOWAIT); @@ -7275,6 +7275,7 @@ static int btrfs_get_blocks_direct_write(struct extent_map **map, struct btrfs_block_group *bg; bool can_nocow = false; bool space_reserved = false; + u64 len = *lenp; u64 prev_len; int ret = 0; @@ -7345,15 +7346,19 @@ static int btrfs_get_blocks_direct_write(struct extent_map **map, free_extent_map(em); *map = NULL; - if (nowait) - return -EAGAIN; + if (nowait) { + ret = -EAGAIN; + goto out; + } /* * If we could not allocate data space before locking the file * range and we can't do a NOCOW write, then we have to fail. */ - if (!dio_data->data_space_reserved) - return -ENOSPC; + if (!dio_data->data_space_reserved) { + ret = -ENOSPC; + goto out; + } /* * We have to COW and we have already reserved data space before, @@ -7394,6 +7399,7 @@ out: btrfs_delalloc_release_extents(BTRFS_I(inode), len); btrfs_delalloc_release_metadata(BTRFS_I(inode), len, true); } + *lenp = len; return ret; } @@ -7570,7 +7576,7 @@ static int btrfs_dio_iomap_begin(struct inode *inode, loff_t start, if (write) { ret = btrfs_get_blocks_direct_write(&em, inode, dio_data, - start, len, flags); + start, &len, flags); if (ret < 0) goto unlock_err; unlock_extents = true; |