diff options
| author | Vegard Nossum <vegard.nossum@oracle.com> | 2016-07-15 03:02:47 (GMT) |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2016-07-15 03:02:47 (GMT) |
| commit | 554a5ccc4e4a20c5f3ec859de0842db4b4b9c77e (patch) | |
| tree | eabafe736e7e667f02a1e7b6f8a0e1721099beb7 | |
| parent | 598c7d7abc832e35677b851f6afb93141c09993b (diff) | |
| download | linux-554a5ccc4e4a20c5f3ec859de0842db4b4b9c77e.tar.xz | |
ext4: fix reference counting bug on block allocation error
If we hit this error when mounted with errors=continue or
errors=remount-ro:
EXT4-fs error (device loop0): ext4_mb_mark_diskspace_used:2940: comm ext4.exe: Allocating blocks 5090-6081 which overlap fs metadata
then ext4_mb_new_blocks() will call ext4_mb_release_context() and try to
continue. However, ext4_mb_release_context() is the wrong thing to call
here since we are still actually using the allocation context.
Instead, just error out. We could retry the allocation, but there is a
possibility of getting stuck in an infinite loop instead, so this seems
safer.
[ Fixed up so we don't return EAGAIN to userspace. --tytso ]
Fixes: 8556e8f3b6 ("ext4: Don't allow new groups to be added during block allocation")
Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org
| -rw-r--r-- | fs/ext4/mballoc.c | 17 |
1 files changed, 3 insertions, 14 deletions
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index 77249e1..1156216 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -2943,7 +2943,7 @@ ext4_mb_mark_diskspace_used(struct ext4_allocation_context *ac, ext4_error(sb, "Allocating blocks %llu-%llu which overlap " "fs metadata", block, block+len); /* File system mounted not to panic on error - * Fix the bitmap and repeat the block allocation + * Fix the bitmap and return EFSCORRUPTED * We leak some of the blocks here. */ ext4_lock_group(sb, ac->ac_b_ex.fe_group); @@ -2952,7 +2952,7 @@ ext4_mb_mark_diskspace_used(struct ext4_allocation_context *ac, ext4_unlock_group(sb, ac->ac_b_ex.fe_group); err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh); if (!err) - err = -EAGAIN; + err = -EFSCORRUPTED; goto out_err; } @@ -4517,18 +4517,7 @@ repeat: } if (likely(ac->ac_status == AC_STATUS_FOUND)) { *errp = ext4_mb_mark_diskspace_used(ac, handle, reserv_clstrs); - if (*errp == -EAGAIN) { - /* - * drop the reference that we took - * in ext4_mb_use_best_found - */ - ext4_mb_release_context(ac); - ac->ac_b_ex.fe_group = 0; - ac->ac_b_ex.fe_start = 0; - ac->ac_b_ex.fe_len = 0; - ac->ac_status = AC_STATUS_CONTINUE; - goto repeat; - } else if (*errp) { + if (*errp) { ext4_discard_allocated_blocks(ac); goto errout; } else { |