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ext4: Fix different block exchange issue in EXT4_IOC_MOVE_EXT 

If logical block offset of original file which is passed to
EXT4_IOC_MOVE_EXT is different from donor file's,
a calculation error occurs in ext4_calc_swap_extents(),
therefore wrong block is exchanged between original file and donor file.
As a result, we hit ext4_error() in check_block_validity().
To detect the logical offset difference in EXT4_IOC_MOVE_EXT,
add checks to mext_calc_swap_extents() and handle it as error,
since data exchange must be done between the same blocks in EXT4_IOC_MOVE_EXT.

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>
hifive-unleashed-5.1
Akira Fujita 2009-09-16 14:25:39 -04:00 committed by Theodore Ts'o
parent 347fa6f1c7
commit c40ce3c9ea
1 changed files with 37 additions and 9 deletions
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46
fs/ext4/move_extent.c
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@ -597,8 +597,10 @@ out:
* @orig_off: block offset of original inode
* @donor_off: block offset of donor inode
* @max_count: the maximun length of extents
*
* Return 0 on success, or a negative error value on failure.
*/
static void
static int
mext_calc_swap_extents(struct ext4_extent *tmp_dext,
struct ext4_extent *tmp_oext,
ext4_lblk_t orig_off, ext4_lblk_t donor_off,
@ -607,6 +609,19 @@ mext_calc_swap_extents(struct ext4_extent *tmp_dext,
ext4_lblk_t diff, orig_diff;
struct ext4_extent dext_old, oext_old;
BUG_ON(orig_off != donor_off);
/* original and donor extents have to cover the same block offset */
if (orig_off < le32_to_cpu(tmp_oext->ee_block) ||
le32_to_cpu(tmp_oext->ee_block) +
ext4_ext_get_actual_len(tmp_oext) - 1 < orig_off)
return -ENODATA;
if (orig_off < le32_to_cpu(tmp_dext->ee_block) ||
le32_to_cpu(tmp_dext->ee_block) +
ext4_ext_get_actual_len(tmp_dext) - 1 < orig_off)
return -ENODATA;
dext_old = *tmp_dext;
oext_old = *tmp_oext;
@ -634,6 +649,8 @@ mext_calc_swap_extents(struct ext4_extent *tmp_dext,
copy_extent_status(&oext_old, tmp_dext);
copy_extent_status(&dext_old, tmp_oext);
return 0;
}
/**
@ -690,8 +707,10 @@ mext_replace_branches(handle_t *handle, struct inode *orig_inode,
dext = donor_path[depth].p_ext;
tmp_dext = *dext;
mext_calc_swap_extents(&tmp_dext, &tmp_oext, orig_off,
err = mext_calc_swap_extents(&tmp_dext, &tmp_oext, orig_off,
donor_off, count);
if (err)
goto out;
/* Loop for the donor extents */
while (1) {
@ -760,9 +779,10 @@ mext_replace_branches(handle_t *handle, struct inode *orig_inode,
}
tmp_dext = *dext;
mext_calc_swap_extents(&tmp_dext, &tmp_oext, orig_off,
donor_off,
count - replaced_count);
err = mext_calc_swap_extents(&tmp_dext, &tmp_oext, orig_off,
donor_off, count - replaced_count);
if (err)
goto out;
}
out:
@ -1243,11 +1263,15 @@ ext4_move_extents(struct file *o_filp, struct file *d_filp,
ext_cur = holecheck_path[depth].p_ext;
/*
* Get proper extent whose ee_block is beyond block_start
* if block_start was within the hole.
* Get proper starting location of block replacement if block_start was
* within the hole.
*/
if (le32_to_cpu(ext_cur->ee_block) +
ext4_ext_get_actual_len(ext_cur) - 1 < block_start) {
/*
* The hole exists between extents or the tail of
* original file.
*/
last_extent = mext_next_extent(orig_inode,
holecheck_path, &ext_cur);
if (last_extent < 0) {
@ -1260,8 +1284,12 @@ ext4_move_extents(struct file *o_filp, struct file *d_filp,
ret1 = last_extent;
goto out;
}
}
seq_start = block_start;
seq_start = le32_to_cpu(ext_cur->ee_block);
} else if (le32_to_cpu(ext_cur->ee_block) > block_start)
/* The hole exists at the beginning of original file. */
seq_start = le32_to_cpu(ext_cur->ee_block);
else
seq_start = block_start;
/* No blocks within the specified range. */
if (le32_to_cpu(ext_cur->ee_block) > block_end) {