ext4: Fix block count in EXT4_IOC_MOVE_EXT failure
From: Akira Fujita <a-fujita@xxxxxxxxxxxxx>
The halfway exchanged block count should be returned to the user-space,
if EXT4_IOC_MOVE_EXT is failed for some reasons
in the environment where block size is not same as page size.
But current EXT4_IOC_MOVE_EXT returns
page-aligned block count to the user-space.
The patch fixes this issue.
Signed-off-by: Akira Fujita <a-fujita@xxxxxxxxxxxxx>
---
fs/ext4/move_extent.c | 139 ++++++++++++++++++++++++++-----------------------
1 files changed, 73 insertions(+), 66 deletions(-)
diff --git a/fs/ext4/move_extent.c b/fs/ext4/move_extent.c
index 25b6b14..83f8c9e 100644
--- a/fs/ext4/move_extent.c
+++ b/fs/ext4/move_extent.c
@@ -661,6 +661,7 @@ mext_calc_swap_extents(struct ext4_extent *tmp_dext,
* @donor_inode: donor inode
* @from: block offset of orig_inode
* @count: block count to be replaced
+ * @err: pointer to save return value
*
* Replace original inode extents and donor inode extents page by page.
* We implement this replacement in the following three steps:
@@ -671,19 +672,18 @@ mext_calc_swap_extents(struct ext4_extent *tmp_dext,
* 3. Change the block information of donor inode to point at the saved
* original inode blocks in the dummy extents.
*
- * Return 0 on success, or a negative error value on failure.
+ * Return replaced block count.
*/
static int
mext_replace_branches(handle_t *handle, struct inode *orig_inode,
struct inode *donor_inode, ext4_lblk_t from,
- ext4_lblk_t count)
+ ext4_lblk_t count, int *err)
{
struct ext4_ext_path *orig_path = NULL;
struct ext4_ext_path *donor_path = NULL;
struct ext4_extent *oext, *dext;
struct ext4_extent tmp_dext, tmp_oext;
ext4_lblk_t orig_off = from, donor_off = from;
- int err = 0;
int depth;
int replaced_count = 0;
int dext_alen;
@@ -691,13 +691,13 @@ mext_replace_branches(handle_t *handle, struct inode *orig_inode,
mext_double_down_write(orig_inode, donor_inode);
/* Get the original extent for the block "orig_off" */
- err = get_ext_path(orig_inode, orig_off, &orig_path);
- if (err)
+ *err = get_ext_path(orig_inode, orig_off, &orig_path);
+ if (*err)
goto out;
/* Get the donor extent for the head */
- err = get_ext_path(donor_inode, donor_off, &donor_path);
- if (err)
+ *err = get_ext_path(donor_inode, donor_off, &donor_path);
+ if (*err)
goto out;
depth = ext_depth(orig_inode);
oext = orig_path[depth].p_ext;
@@ -707,9 +707,9 @@ mext_replace_branches(handle_t *handle, struct inode *orig_inode,
dext = donor_path[depth].p_ext;
tmp_dext = *dext;
- err = 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)
+ if (*err)
goto out;
/* Loop for the donor extents */
@@ -718,7 +718,7 @@ mext_replace_branches(handle_t *handle, struct inode *orig_inode,
if (!dext) {
ext4_error(donor_inode->i_sb, __func__,
"The extent for donor must be found");
- err = -EIO;
+ *err = -EIO;
goto out;
} else if (donor_off != le32_to_cpu(tmp_dext.ee_block)) {
ext4_error(donor_inode->i_sb, __func__,
@@ -726,20 +726,20 @@ mext_replace_branches(handle_t *handle, struct inode *orig_inode,
"extent(%u) should be equal",
donor_off,
le32_to_cpu(tmp_dext.ee_block));
- err = -EIO;
+ *err = -EIO;
goto out;
}
/* Set donor extent to orig extent */
- err = mext_leaf_block(handle, orig_inode,
+ *err = mext_leaf_block(handle, orig_inode,
orig_path, &tmp_dext, &orig_off);
- if (err < 0)
+ if (*err)
goto out;
/* Set orig extent to donor extent */
- err = mext_leaf_block(handle, donor_inode,
+ *err = mext_leaf_block(handle, donor_inode,
donor_path, &tmp_oext, &donor_off);
- if (err < 0)
+ if (*err)
goto out;
dext_alen = ext4_ext_get_actual_len(&tmp_dext);
@@ -753,35 +753,25 @@ 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 (err)
+ *err = get_ext_path(orig_inode, orig_off, &orig_path);
+ if (*err)
goto out;
depth = ext_depth(orig_inode);
oext = orig_path[depth].p_ext;
- if (le32_to_cpu(oext->ee_block) +
- ext4_ext_get_actual_len(oext) <= orig_off) {
- err = 0;
- goto out;
- }
tmp_oext = *oext;
if (donor_path)
ext4_ext_drop_refs(donor_path);
- err = get_ext_path(donor_inode, donor_off, &donor_path);
- if (err)
+ *err = get_ext_path(donor_inode, donor_off, &donor_path);
+ if (*err)
goto out;
depth = ext_depth(donor_inode);
dext = donor_path[depth].p_ext;
- if (le32_to_cpu(dext->ee_block) +
- ext4_ext_get_actual_len(dext) <= donor_off) {
- err = 0;
- goto out;
- }
tmp_dext = *dext;
- err = mext_calc_swap_extents(&tmp_dext, &tmp_oext, orig_off,
+ *err = mext_calc_swap_extents(&tmp_dext, &tmp_oext, orig_off,
donor_off, count - replaced_count);
- if (err)
+ if (*err)
goto out;
}
@@ -796,7 +786,7 @@ out:
}
mext_double_up_write(orig_inode, donor_inode);
- return err;
+ return replaced_count;
}
/**
@@ -808,16 +798,17 @@ out:
* @data_offset_in_page: block index where data swapping starts
* @block_len_in_page: the number of blocks to be swapped
* @uninit: orig extent is uninitialized or not
+ * @err: pointer to save return value
*
* Save the data in original inode blocks and replace original inode extents
* with donor inode extents by calling mext_replace_branches().
- * Finally, write out the saved data in new original inode blocks. Return 0
- * on success, or a negative error value on failure.
+ * Finally, write out the saved data in new original inode blocks. Return
+ * replaced block count.
*/
static int
move_extent_per_page(struct file *o_filp, struct inode *donor_inode,
pgoff_t orig_page_offset, int data_offset_in_page,
- int block_len_in_page, int uninit)
+ int block_len_in_page, int uninit, int *err)
{
struct inode *orig_inode = o_filp->f_dentry->d_inode;
struct address_space *mapping = orig_inode->i_mapping;
@@ -829,9 +820,11 @@ move_extent_per_page(struct file *o_filp, struct inode *donor_inode,
long long offs = orig_page_offset << PAGE_CACHE_SHIFT;
unsigned long blocksize = orig_inode->i_sb->s_blocksize;
unsigned int w_flags = 0;
- unsigned int tmp_data_len, data_len;
+ unsigned int tmp_data_size, data_size, replaced_size;
void *fsdata;
- int ret, i, jblocks;
+ int i, jblocks;
+ int err2 = 0;
+ int replaced_count = 0;
int blocks_per_page = PAGE_CACHE_SIZE >> orig_inode->i_blkbits;
/*
@@ -841,8 +834,8 @@ move_extent_per_page(struct file *o_filp, struct inode *donor_inode,
jblocks = ext4_writepage_trans_blocks(orig_inode) * 2;
handle = ext4_journal_start(orig_inode, jblocks);
if (IS_ERR(handle)) {
- ret = PTR_ERR(handle);
- return ret;
+ *err = PTR_ERR(handle);
+ return 0;
}
if (segment_eq(get_fs(), KERNEL_DS))
@@ -858,9 +851,9 @@ move_extent_per_page(struct file *o_filp, struct inode *donor_inode,
* Just swap data blocks between orig and donor.
*/
if (uninit) {
- ret = mext_replace_branches(handle, orig_inode,
- donor_inode, orig_blk_offset,
- block_len_in_page);
+ replaced_count = mext_replace_branches(handle, orig_inode,
+ donor_inode, orig_blk_offset,
+ block_len_in_page, err);
/* Clear the inode cache not to refer to the old data */
ext4_ext_invalidate_cache(orig_inode);
@@ -870,27 +863,28 @@ move_extent_per_page(struct file *o_filp, struct inode *donor_inode,
offs = (long long)orig_blk_offset << orig_inode->i_blkbits;
- /* Calculate data_len */
+ /* Calculate data_size */
if ((orig_blk_offset + block_len_in_page - 1) ==
((orig_inode->i_size - 1) >> orig_inode->i_blkbits)) {
/* Replace the last block */
- tmp_data_len = orig_inode->i_size & (blocksize - 1);
+ tmp_data_size = orig_inode->i_size & (blocksize - 1);
/*
- * If data_len equal zero, it shows data_len is multiples of
+ * If data_size equal zero, it shows data_size is multiples of
* blocksize. So we set appropriate value.
*/
- if (tmp_data_len == 0)
- tmp_data_len = blocksize;
+ if (tmp_data_size == 0)
+ tmp_data_size = blocksize;
- data_len = tmp_data_len +
+ data_size = tmp_data_size +
((block_len_in_page - 1) << orig_inode->i_blkbits);
- } else {
- data_len = block_len_in_page << orig_inode->i_blkbits;
- }
+ } else
+ data_size = block_len_in_page << orig_inode->i_blkbits;
+
+ replaced_size = data_size;
- ret = a_ops->write_begin(o_filp, mapping, offs, data_len, w_flags,
+ *err = a_ops->write_begin(o_filp, mapping, offs, data_size, w_flags,
&page, &fsdata);
- if (unlikely(ret < 0))
+ if (unlikely(*err < 0))
goto out;
if (!PageUptodate(page)) {
@@ -911,10 +905,17 @@ move_extent_per_page(struct file *o_filp, struct inode *donor_inode,
/* Release old bh and drop refs */
try_to_release_page(page, 0);
- ret = mext_replace_branches(handle, orig_inode, donor_inode,
- orig_blk_offset, block_len_in_page);
- if (ret < 0)
- goto out;
+ replaced_count = mext_replace_branches(handle, orig_inode, donor_inode,
+ orig_blk_offset, block_len_in_page,
+ &err2);
+ if (err2) {
+ if (replaced_count) {
+ block_len_in_page = replaced_count;
+ replaced_size =
+ block_len_in_page << orig_inode->i_blkbits;
+ } else
+ goto out;
+ }
/* Clear the inode cache not to refer to the old data */
ext4_ext_invalidate_cache(orig_inode);
@@ -928,16 +929,16 @@ move_extent_per_page(struct file *o_filp, struct inode *donor_inode,
bh = bh->b_this_page;
for (i = 0; i < block_len_in_page; i++) {
- ret = ext4_get_block(orig_inode,
+ *err = ext4_get_block(orig_inode,
(sector_t)(orig_blk_offset + i), bh, 0);
- if (ret < 0)
+ if (*err < 0)
goto out;
if (bh->b_this_page != NULL)
bh = bh->b_this_page;
}
- ret = a_ops->write_end(o_filp, mapping, offs, data_len, data_len,
+ *err = a_ops->write_end(o_filp, mapping, offs, data_size, replaced_size,
page, fsdata);
page = NULL;
@@ -951,7 +952,10 @@ out:
out2:
ext4_journal_stop(handle);
- return ret < 0 ? ret : 0;
+ if (err2)
+ *err = err2;
+
+ return replaced_count;
}
/**
@@ -1367,15 +1371,17 @@ ext4_move_extents(struct file *o_filp, struct file *d_filp,
while (orig_page_offset <= seq_end_page) {
/* Swap original branches with new branches */
- ret1 = move_extent_per_page(o_filp, donor_inode,
+ block_len_in_page = move_extent_per_page(
+ o_filp, donor_inode,
orig_page_offset,
data_offset_in_page,
- block_len_in_page, uninit);
- if (ret1 < 0)
- goto out;
- orig_page_offset++;
+ block_len_in_page, uninit,
+ &ret1);
+
/* Count how many blocks we have exchanged */
*moved_len += block_len_in_page;
+ if (ret1 < 0)
+ goto out;
if (*moved_len > len) {
ext4_error(orig_inode->i_sb, __func__,
"We replaced blocks too much! "
@@ -1385,6 +1391,7 @@ ext4_move_extents(struct file *o_filp, struct file *d_filp,
goto out;
}
+ orig_page_offset++;
data_offset_in_page = 0;
rest_blocks -= block_len_in_page;
if (rest_blocks > blocks_per_page)
--
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