Commit 345ee947 authored by Eric Whitney's avatar Eric Whitney Committed by Theodore Ts'o

ext4: miscellaneous partial cluster cleanups

Add some casts and rearrange a few statements for improved readability.
Some code can also be simplified and made more readable if we set
partial_cluster to 0 rather than to a negative value when we can tell
we've hit the left edge of the punched region.
Signed-off-by: default avatarEric Whitney <enwlinux@gmail.com>
Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
parent 5bf43760
......@@ -2481,7 +2481,7 @@ static int ext4_remove_blocks(handle_t *handle, struct inode *inode,
ext4_lblk_t from, ext4_lblk_t to)
{
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
unsigned short ee_len = ext4_ext_get_actual_len(ex);
unsigned short ee_len = ext4_ext_get_actual_len(ex);
ext4_fsblk_t pblk;
int flags = get_default_free_blocks_flags(inode);
......@@ -2490,7 +2490,7 @@ static int ext4_remove_blocks(handle_t *handle, struct inode *inode,
* at the beginning of the extent. Instead, we make a note
* that we tried freeing the cluster, and check to see if we
* need to free it on a subsequent call to ext4_remove_blocks,
* or at the end of the ext4_truncate() operation.
* or at the end of ext4_ext_rm_leaf or ext4_ext_remove_space.
*/
flags |= EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER;
......@@ -2501,8 +2501,8 @@ static int ext4_remove_blocks(handle_t *handle, struct inode *inode,
* partial cluster here.
*/
pblk = ext4_ext_pblock(ex) + ee_len - 1;
if ((*partial_cluster > 0) &&
(EXT4_B2C(sbi, pblk) != *partial_cluster)) {
if (*partial_cluster > 0 &&
*partial_cluster != (long long) EXT4_B2C(sbi, pblk)) {
ext4_free_blocks(handle, inode, NULL,
EXT4_C2B(sbi, *partial_cluster),
sbi->s_cluster_ratio, flags);
......@@ -2528,7 +2528,7 @@ static int ext4_remove_blocks(handle_t *handle, struct inode *inode,
&& to == le32_to_cpu(ex->ee_block) + ee_len - 1) {
/* tail removal */
ext4_lblk_t num;
unsigned int unaligned;
long long first_cluster;
num = le32_to_cpu(ex->ee_block) + ee_len - from;
pblk = ext4_ext_pblock(ex) + ee_len - num;
......@@ -2538,7 +2538,7 @@ static int ext4_remove_blocks(handle_t *handle, struct inode *inode,
* used by any other extent (partial_cluster is negative).
*/
if (*partial_cluster < 0 &&
-(*partial_cluster) == EXT4_B2C(sbi, pblk + num - 1))
*partial_cluster == -(long long) EXT4_B2C(sbi, pblk+num-1))
flags |= EXT4_FREE_BLOCKS_NOFREE_LAST_CLUSTER;
ext_debug("free last %u blocks starting %llu partial %lld\n",
......@@ -2549,21 +2549,24 @@ static int ext4_remove_blocks(handle_t *handle, struct inode *inode,
* beginning of a cluster, and we removed the entire
* extent and the cluster is not used by any other extent,
* save the partial cluster here, since we might need to
* delete if we determine that the truncate operation has
* removed all of the blocks in the cluster.
* delete if we determine that the truncate or punch hole
* operation has removed all of the blocks in the cluster.
* If that cluster is used by another extent, preserve its
* negative value so it isn't freed later on.
*
* On the other hand, if we did not manage to free the whole
* extent, we have to mark the cluster as used (store negative
* cluster number in partial_cluster).
* If the whole extent wasn't freed, we've reached the
* start of the truncated/punched region and have finished
* removing blocks. If there's a partial cluster here it's
* shared with the remainder of the extent and is no longer
* a candidate for removal.
*/
unaligned = EXT4_PBLK_COFF(sbi, pblk);
if (unaligned && (ee_len == num) &&
(*partial_cluster != -((long long)EXT4_B2C(sbi, pblk))))
*partial_cluster = EXT4_B2C(sbi, pblk);
else if (unaligned)
*partial_cluster = -((long long)EXT4_B2C(sbi, pblk));
else if (*partial_cluster > 0)
if (EXT4_PBLK_COFF(sbi, pblk) && ee_len == num) {
first_cluster = (long long) EXT4_B2C(sbi, pblk);
if (first_cluster != -*partial_cluster)
*partial_cluster = first_cluster;
} else {
*partial_cluster = 0;
}
} else
ext4_error(sbi->s_sb, "strange request: removal(2) "
"%u-%u from %u:%u\n",
......
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