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ocfs2: do not set fs read-only if rec[0] is empty while committing truncate

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While appending an extent to a file, it will call these functions:
ocfs2_insert_extent

  -> call ocfs2_grow_tree() if there's no free rec
     -> ocfs2_add_branch add a new branch to extent tree,
        now rec[0] in the leaf of rightmost path is empty
  -> ocfs2_do_insert_extent
     -> ocfs2_rotate_tree_right
       -> ocfs2_extend_rotate_transaction
          -> jbd2_journal_restart if jbd2_journal_extend fail
     -> ocfs2_insert_path
        -> ocfs2_extend_trans
          -> jbd2_journal_restart if jbd2_journal_extend fail
        -> ocfs2_insert_at_leaf
     -> ocfs2_et_update_clusters
Function jbd2_journal_restart() may be called and it may happened that
buffers dirtied in ocfs2_add_branch() are committed
while buffers dirtied in ocfs2_insert_at_leaf() and
ocfs2_et_update_clusters() are not.
So an empty rec[0] is left in rightmost path which will cause
read-only filesystem when call ocfs2_commit_truncate()
with the error message: "Inode %lu has an empty extent record".

This is not a serious problem, so remove the rightmost path when call
ocfs2_commit_truncate().

Signed-off-by: joyce.xue <xuejiufei@huawei.com>
Reviewed-by: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Xue jiufei 2015-09-04 15:44:48 -07:00 committed by Linus Torvalds
parent 7f27ec978b
commit d0c97d52f5
1 changed files with 38 additions and 6 deletions
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44
fs/ocfs2/alloc.c
View file

@ -3131,6 +3131,30 @@ out:
return ret;
}
static int ocfs2_remove_rightmost_empty_extent(struct ocfs2_super *osb,
struct ocfs2_extent_tree *et,
struct ocfs2_path *path,
struct ocfs2_cached_dealloc_ctxt *dealloc)
{
handle_t *handle;
int ret;
int credits = path->p_tree_depth * 2 + 1;
handle = ocfs2_start_trans(osb, credits);
if (IS_ERR(handle)) {
ret = PTR_ERR(handle);
mlog_errno(ret);
return ret;
}
ret = ocfs2_remove_rightmost_path(handle, et, path, dealloc);
if (ret)
mlog_errno(ret);
ocfs2_commit_trans(osb, handle);
return ret;
}
/*
* Left rotation of btree records.
*
@ -7108,15 +7132,23 @@ start:
* to check it up here before changing the tree.
*/
if (root_el->l_tree_depth && rec->e_int_clusters == 0) {
ocfs2_error(inode->i_sb, "Inode %lu has an empty "
mlog(ML_ERROR, "Inode %lu has an empty "
"extent record, depth %u\n", inode->i_ino,
le16_to_cpu(root_el->l_tree_depth));
status = -EROFS;
goto bail;
status = ocfs2_remove_rightmost_empty_extent(osb,
&et, path, &dealloc);
if (status) {
mlog_errno(status);
goto bail;
}
ocfs2_reinit_path(path, 1);
goto start;
} else {
trunc_cpos = le32_to_cpu(rec->e_cpos);
trunc_len = 0;
blkno = 0;
}
trunc_cpos = le32_to_cpu(rec->e_cpos);
trunc_len = 0;
blkno = 0;
} else if (le32_to_cpu(rec->e_cpos) >= new_highest_cpos) {
/*
* Truncate entire record.