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author | Baokun Li <libaokun1@huawei.com> | 2022-04-28 16:40:31 +0300 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-07-21 22:20:02 +0300 |
commit | 91f90b571f1a23f5b8a9c2b68a9aa5d6981a3c3d (patch) | |
tree | 6eedbb5b714f7d1616df77a372b48ca93d2da55c /fs | |
parent | 9d883b3f000d405d19b3484e3d8d97796e6854c6 (diff) | |
download | linux-91f90b571f1a23f5b8a9c2b68a9aa5d6981a3c3d.tar.xz |
ext4: fix race condition between ext4_write and ext4_convert_inline_data
commit f87c7a4b084afc13190cbb263538e444cb2b392a upstream.
Hulk Robot reported a BUG_ON:
==================================================================
EXT4-fs error (device loop3): ext4_mb_generate_buddy:805: group 0,
block bitmap and bg descriptor inconsistent: 25 vs 31513 free clusters
kernel BUG at fs/ext4/ext4_jbd2.c:53!
invalid opcode: 0000 [#1] SMP KASAN PTI
CPU: 0 PID: 25371 Comm: syz-executor.3 Not tainted 5.10.0+ #1
RIP: 0010:ext4_put_nojournal fs/ext4/ext4_jbd2.c:53 [inline]
RIP: 0010:__ext4_journal_stop+0x10e/0x110 fs/ext4/ext4_jbd2.c:116
[...]
Call Trace:
ext4_write_inline_data_end+0x59a/0x730 fs/ext4/inline.c:795
generic_perform_write+0x279/0x3c0 mm/filemap.c:3344
ext4_buffered_write_iter+0x2e3/0x3d0 fs/ext4/file.c:270
ext4_file_write_iter+0x30a/0x11c0 fs/ext4/file.c:520
do_iter_readv_writev+0x339/0x3c0 fs/read_write.c:732
do_iter_write+0x107/0x430 fs/read_write.c:861
vfs_writev fs/read_write.c:934 [inline]
do_pwritev+0x1e5/0x380 fs/read_write.c:1031
[...]
==================================================================
Above issue may happen as follows:
cpu1 cpu2
__________________________|__________________________
do_pwritev
vfs_writev
do_iter_write
ext4_file_write_iter
ext4_buffered_write_iter
generic_perform_write
ext4_da_write_begin
vfs_fallocate
ext4_fallocate
ext4_convert_inline_data
ext4_convert_inline_data_nolock
ext4_destroy_inline_data_nolock
clear EXT4_STATE_MAY_INLINE_DATA
ext4_map_blocks
ext4_ext_map_blocks
ext4_mb_new_blocks
ext4_mb_regular_allocator
ext4_mb_good_group_nolock
ext4_mb_init_group
ext4_mb_init_cache
ext4_mb_generate_buddy --> error
ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)
ext4_restore_inline_data
set EXT4_STATE_MAY_INLINE_DATA
ext4_block_write_begin
ext4_da_write_end
ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)
ext4_write_inline_data_end
handle=NULL
ext4_journal_stop(handle)
__ext4_journal_stop
ext4_put_nojournal(handle)
ref_cnt = (unsigned long)handle
BUG_ON(ref_cnt == 0) ---> BUG_ON
The lock held by ext4_convert_inline_data is xattr_sem, but the lock
held by generic_perform_write is i_rwsem. Therefore, the two locks can
be concurrent.
To solve above issue, we add inode_lock() for ext4_convert_inline_data().
At the same time, move ext4_convert_inline_data() in front of
ext4_punch_hole(), remove similar handling from ext4_punch_hole().
Fixes: 0c8d414f163f ("ext4: let fallocate handle inline data correctly")
Cc: stable@vger.kernel.org
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Baokun Li <libaokun1@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20220428134031.4153381-1-libaokun1@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Tadeusz Struk <tadeusz.struk@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs')
-rw-r--r-- | fs/ext4/extents.c | 9 | ||||
-rw-r--r-- | fs/ext4/inode.c | 9 |
2 files changed, 5 insertions, 13 deletions
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index 6641b74ad462..0f49bf547b84 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -4691,16 +4691,17 @@ long ext4_fallocate(struct file *file, int mode, loff_t offset, loff_t len) return -EOPNOTSUPP; ext4_fc_start_update(inode); + inode_lock(inode); + ret = ext4_convert_inline_data(inode); + inode_unlock(inode); + if (ret) + goto exit; if (mode & FALLOC_FL_PUNCH_HOLE) { ret = ext4_punch_hole(file, offset, len); goto exit; } - ret = ext4_convert_inline_data(inode); - if (ret) - goto exit; - if (mode & FALLOC_FL_COLLAPSE_RANGE) { ret = ext4_collapse_range(file, offset, len); goto exit; diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 72e3f55f1e07..bd0d0a10ca42 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -4042,15 +4042,6 @@ int ext4_punch_hole(struct file *file, loff_t offset, loff_t length) trace_ext4_punch_hole(inode, offset, length, 0); - ext4_clear_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA); - if (ext4_has_inline_data(inode)) { - down_write(&EXT4_I(inode)->i_mmap_sem); - ret = ext4_convert_inline_data(inode); - up_write(&EXT4_I(inode)->i_mmap_sem); - if (ret) - return ret; - } - /* * Write out all dirty pages to avoid race conditions * Then release them. |