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authorBaokun Li <libaokun1@huawei.com>2022-04-28 16:40:31 +0300
committerTheodore Ts'o <tytso@mit.edu>2022-05-17 21:17:40 +0300
commitf87c7a4b084afc13190cbb263538e444cb2b392a (patch)
tree59e874179b996c2935ecb0a7db292fefc7aecf6b /fs/ext4/extents.c
parent6493792d3299b3e33f887ef8a150099d271faf9c (diff)
downloadlinux-f87c7a4b084afc13190cbb263538e444cb2b392a.tar.xz
ext4: fix race condition between ext4_write and ext4_convert_inline_data
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>
Diffstat (limited to 'fs/ext4/extents.c')
-rw-r--r--fs/ext4/extents.c10
1 files changed, 6 insertions, 4 deletions
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index e473fde6b64b..474479ce76e0 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -4693,15 +4693,17 @@ long ext4_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
FALLOC_FL_INSERT_RANGE))
return -EOPNOTSUPP;
+ 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;