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| author | yangerkun <yangerkun@huawei.com> | 2021-09-03 14:27:48 +0800 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2021-11-04 10:33:24 -0400 |
| commit | 1811bc401aa58c7bdb0df3205aa6613b49d32127 (patch) | |
| tree | 57a8b2d29d4637e2572909c9dc98bbb5cf63392d /fs/ext4/extents.c | |
| parent | 4268496e48dc681cfa53b92357314b5d7221e625 (diff) | |
| download | linux-1811bc401aa58c7bdb0df3205aa6613b49d32127.tar.gz | |
ext4: refresh the ext4_ext_path struct after dropping i_data_sem.
After we drop i_data sem, we need to reload the ext4_ext_path
structure since the extent tree can change once i_data_sem is
released.
This addresses the BUG:
[52117.465187] ------------[ cut here ]------------
[52117.465686] kernel BUG at fs/ext4/extents.c:1756!
...
[52117.478306] Call Trace:
[52117.478565] ext4_ext_shift_extents+0x3ee/0x710
[52117.479020] ext4_fallocate+0x139c/0x1b40
[52117.479405] ? __do_sys_newfstat+0x6b/0x80
[52117.479805] vfs_fallocate+0x151/0x4b0
[52117.480177] ksys_fallocate+0x4a/0xa0
[52117.480533] __x64_sys_fallocate+0x22/0x30
[52117.480930] do_syscall_64+0x35/0x80
[52117.481277] entry_SYSCALL_64_after_hwframe+0x44/0xae
[52117.481769] RIP: 0033:0x7fa062f855ca
Cc: stable@kernel.org
Link: https://lore.kernel.org/r/20210903062748.4118886-4-yangerkun@huawei.com
Signed-off-by: yangerkun <yangerkun@huawei.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Diffstat (limited to 'fs/ext4/extents.c')
| -rw-r--r-- | fs/ext4/extents.c | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index 6b080f61342a2a..15c68bc80d21b0 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -5014,8 +5014,11 @@ ext4_ext_shift_path_extents(struct ext4_ext_path *path, ext4_lblk_t shift, restart_credits = ext4_writepage_trans_blocks(inode); err = ext4_datasem_ensure_credits(handle, inode, credits, restart_credits, 0); - if (err) + if (err) { + if (err > 0) + err = -EAGAIN; goto out; + } err = ext4_ext_get_access(handle, inode, path + depth); if (err) @@ -5089,6 +5092,7 @@ ext4_ext_shift_extents(struct inode *inode, handle_t *handle, int ret = 0, depth; struct ext4_extent *extent; ext4_lblk_t stop, *iterator, ex_start, ex_end; + ext4_lblk_t tmp = EXT_MAX_BLOCKS; /* Let path point to the last extent */ path = ext4_find_extent(inode, EXT_MAX_BLOCKS - 1, NULL, @@ -5142,11 +5146,15 @@ ext4_ext_shift_extents(struct inode *inode, handle_t *handle, * till we reach stop. In case of right shift, iterator points to stop * and it is decreased till we reach start. */ +again: if (SHIFT == SHIFT_LEFT) iterator = &start; else iterator = &stop; + if (tmp != EXT_MAX_BLOCKS) + *iterator = tmp; + /* * Its safe to start updating extents. Start and stop are unsigned, so * in case of right shift if extent with 0 block is reached, iterator @@ -5175,6 +5183,7 @@ ext4_ext_shift_extents(struct inode *inode, handle_t *handle, } } + tmp = *iterator; if (SHIFT == SHIFT_LEFT) { extent = EXT_LAST_EXTENT(path[depth].p_hdr); *iterator = le32_to_cpu(extent->ee_block) + @@ -5193,6 +5202,9 @@ ext4_ext_shift_extents(struct inode *inode, handle_t *handle, } ret = ext4_ext_shift_path_extents(path, shift, inode, handle, SHIFT); + /* iterator can be NULL which means we should break */ + if (ret == -EAGAIN) + goto again; if (ret) break; } |