ext4: Add null extent check to ext_get_path

There is the possibility that path structure which is taken
by ext4_ext_find_extent() indicates null extents.
Because during data block exchanging in ext4_move_extents(),
constitution of an extent tree may be changed.
As a solution, the patch adds null extent check
to ext_get_path().

Reported-by: Peng Tao <bergwolf@gmail.com>
Signed-off-by: Akira Fujita <a-fujita@rs.jp.nec.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This commit is contained in:
Akira Fujita 2009-09-16 14:25:07 -04:00 committed by Theodore Ts'o
parent 2147b1a6a4
commit 347fa6f1c7

View File

@ -39,7 +39,9 @@ get_ext_path(struct inode *inode, ext4_lblk_t lblock,
if (IS_ERR(*path)) {
ret = PTR_ERR(*path);
*path = NULL;
}
} else if ((*path)[ext_depth(inode)].p_ext == NULL)
ret = -ENODATA;
return ret;
}
@ -316,7 +318,7 @@ mext_insert_across_blocks(handle_t *handle, struct inode *orig_inode,
if (new_flag) {
err = get_ext_path(orig_inode, eblock, &orig_path);
if (orig_path == NULL)
if (err)
goto out;
if (ext4_ext_insert_extent(handle, orig_inode,
@ -327,7 +329,7 @@ mext_insert_across_blocks(handle_t *handle, struct inode *orig_inode,
if (end_flag) {
err = get_ext_path(orig_inode,
le32_to_cpu(end_ext->ee_block) - 1, &orig_path);
if (orig_path == NULL)
if (err)
goto out;
if (ext4_ext_insert_extent(handle, orig_inode,
@ -673,12 +675,12 @@ mext_replace_branches(handle_t *handle, struct inode *orig_inode,
/* Get the original extent for the block "orig_off" */
err = get_ext_path(orig_inode, orig_off, &orig_path);
if (orig_path == NULL)
if (err)
goto out;
/* Get the donor extent for the head */
err = get_ext_path(donor_inode, donor_off, &donor_path);
if (donor_path == NULL)
if (err)
goto out;
depth = ext_depth(orig_inode);
oext = orig_path[depth].p_ext;
@ -733,7 +735,7 @@ mext_replace_branches(handle_t *handle, struct inode *orig_inode,
if (orig_path)
ext4_ext_drop_refs(orig_path);
err = get_ext_path(orig_inode, orig_off, &orig_path);
if (orig_path == NULL)
if (err)
goto out;
depth = ext_depth(orig_inode);
oext = orig_path[depth].p_ext;
@ -747,7 +749,7 @@ mext_replace_branches(handle_t *handle, struct inode *orig_inode,
if (donor_path)
ext4_ext_drop_refs(donor_path);
err = get_ext_path(donor_inode, donor_off, &donor_path);
if (donor_path == NULL)
if (err)
goto out;
depth = ext_depth(donor_inode);
dext = donor_path[depth].p_ext;
@ -1221,7 +1223,7 @@ ext4_move_extents(struct file *o_filp, struct file *d_filp,
donor_start, &len, *moved_len);
mext_double_up_read(orig_inode, donor_inode);
if (ret1)
goto out2;
goto out;
file_end = (i_size_read(orig_inode) - 1) >> orig_inode->i_blkbits;
block_end = block_start + len - 1;
@ -1229,20 +1231,16 @@ ext4_move_extents(struct file *o_filp, struct file *d_filp,
len -= block_end - file_end;
ret1 = get_ext_path(orig_inode, block_start, &orig_path);
if (orig_path == NULL)
goto out2;
if (ret1)
goto out;
/* Get path structure to check the hole */
ret1 = get_ext_path(orig_inode, block_start, &holecheck_path);
if (holecheck_path == NULL)
if (ret1)
goto out;
depth = ext_depth(orig_inode);
ext_cur = holecheck_path[depth].p_ext;
if (ext_cur == NULL) {
ret1 = -EINVAL;
goto out;
}
/*
* Get proper extent whose ee_block is beyond block_start
@ -1371,7 +1369,7 @@ ext4_move_extents(struct file *o_filp, struct file *d_filp,
if (holecheck_path)
ext4_ext_drop_refs(holecheck_path);
ret1 = get_ext_path(orig_inode, seq_start, &holecheck_path);
if (holecheck_path == NULL)
if (ret1)
break;
depth = holecheck_path->p_depth;
@ -1379,7 +1377,7 @@ ext4_move_extents(struct file *o_filp, struct file *d_filp,
if (orig_path)
ext4_ext_drop_refs(orig_path);
ret1 = get_ext_path(orig_inode, seq_start, &orig_path);
if (orig_path == NULL)
if (ret1)
break;
ext_cur = holecheck_path[depth].p_ext;
@ -1396,7 +1394,7 @@ out:
ext4_ext_drop_refs(holecheck_path);
kfree(holecheck_path);
}
out2:
ret2 = mext_inode_double_unlock(orig_inode, donor_inode);
if (ret1)