From: Yuezhang Mo <Yuezhang.Mo@xxxxxxxx>
Before this conversion, each dentry traversed needs to be read
from the storage device or page cache. There are at least 16
dentries in a sector. This will result in frequent page cache
searches.
After this conversion, if all directory entries in a sector are
used, the sector only needs to be read once.
Signed-off-by: Yuezhang Mo <Yuezhang.Mo@xxxxxxxx>
Reviewed-by: Andy Wu <Andy.Wu@xxxxxxxx>
Reviewed-by: Aoyama Wataru <wataru.aoyama@xxxxxxxx>
---
fs/exfat/namei.c | 111 ++++++++++++++++++++---------------------------
1 file changed, 47 insertions(+), 64 deletions(-)
diff --git a/fs/exfat/namei.c b/fs/exfat/namei.c
index 9c549fd11fc8..1f662296f2fa 100644
--- a/fs/exfat/namei.c
+++ b/fs/exfat/namei.c
@@ -204,21 +204,16 @@ const struct dentry_operations exfat_utf8_dentry_ops = {
.d_compare = exfat_utf8_d_cmp,
};
-/* used only in search empty_slot() */
-#define CNT_UNUSED_NOHIT (-1)
-#define CNT_UNUSED_HIT (-2)
/* search EMPTY CONTINUOUS "num_entries" entries */
static int exfat_search_empty_slot(struct super_block *sb,
struct exfat_hint_femp *hint_femp, struct exfat_chain *p_dir,
- int num_entries)
+ int num_entries, struct exfat_entry_set_cache *es)
{
- int i, dentry, num_empty = 0;
+ int i, dentry, ret;
int dentries_per_clu;
- unsigned int type;
struct exfat_chain clu;
- struct exfat_dentry *ep;
struct exfat_sb_info *sbi = EXFAT_SB(sb);
- struct buffer_head *bh;
+ int total_entries = EXFAT_CLU_TO_DEN(p_dir->size, sbi);
dentries_per_clu = sbi->dentries_per_clu;
@@ -231,7 +226,7 @@ static int exfat_search_empty_slot(struct super_block *sb,
* Otherwise, and if "dentry + hint_famp->count" is also equal
* to "p_dir->size * dentries_per_clu", it means ENOSPC.
*/
- if (dentry + hint_femp->count == p_dir->size * dentries_per_clu &&
+ if (dentry + hint_femp->count == total_entries &&
num_entries > hint_femp->count)
return -ENOSPC;
@@ -242,69 +237,41 @@ static int exfat_search_empty_slot(struct super_block *sb,
dentry = 0;
}
- while (clu.dir != EXFAT_EOF_CLUSTER) {
+ while (dentry + num_entries < total_entries &&
+ clu.dir != EXFAT_EOF_CLUSTER) {
i = dentry & (dentries_per_clu - 1);
- for (; i < dentries_per_clu; i++, dentry++) {
- ep = exfat_get_dentry(sb, &clu, i, &bh);
- if (!ep)
- return -EIO;
- type = exfat_get_entry_type(ep);
- brelse(bh);
-
- if (type == TYPE_UNUSED || type == TYPE_DELETED) {
- num_empty++;
- if (hint_femp->eidx == EXFAT_HINT_NONE) {
- hint_femp->eidx = dentry;
- hint_femp->count = CNT_UNUSED_NOHIT;
- exfat_chain_set(&hint_femp->cur,
- clu.dir, clu.size, clu.flags);
- }
-
- if (type == TYPE_UNUSED &&
- hint_femp->count != CNT_UNUSED_HIT)
- hint_femp->count = CNT_UNUSED_HIT;
+ ret = exfat_get_empty_dentry_set(es, sb, &clu, i, num_entries);
+ if (ret < 0)
+ return ret;
+ else if (ret == 0)
+ return dentry;
+
+ dentry += ret;
+ i += ret;
+
+ while (i >= dentries_per_clu) {
+ if (clu.flags == ALLOC_NO_FAT_CHAIN) {
+ if (--clu.size > 0)
+ clu.dir++;
+ else
+ clu.dir = EXFAT_EOF_CLUSTER;
} else {
- if (hint_femp->eidx != EXFAT_HINT_NONE &&
- hint_femp->count == CNT_UNUSED_HIT) {
- /* unused empty group means
- * an empty group which includes
- * unused dentry
- */
- exfat_fs_error(sb,
- "found bogus dentry(%d) beyond unused empty group(%d) (start_clu : %u, cur_clu : %u)",
- dentry, hint_femp->eidx,
- p_dir->dir, clu.dir);
+ if (exfat_get_next_cluster(sb, &clu.dir))
return -EIO;
- }
-
- num_empty = 0;
- hint_femp->eidx = EXFAT_HINT_NONE;
}
- if (num_empty >= num_entries) {
- /* found and invalidate hint_femp */
- hint_femp->eidx = EXFAT_HINT_NONE;
- return (dentry - (num_entries - 1));
- }
- }
-
- if (clu.flags == ALLOC_NO_FAT_CHAIN) {
- if (--clu.size > 0)
- clu.dir++;
- else
- clu.dir = EXFAT_EOF_CLUSTER;
- } else {
- if (exfat_get_next_cluster(sb, &clu.dir))
- return -EIO;
+ i -= dentries_per_clu;
}
}
- hint_femp->eidx = p_dir->size * dentries_per_clu - num_empty;
- hint_femp->count = num_empty;
- if (num_empty == 0)
+ hint_femp->eidx = dentry;
+ hint_femp->count = 0;
+ if (dentry == total_entries || clu.dir == EXFAT_EOF_CLUSTER)
exfat_chain_set(&hint_femp->cur, EXFAT_EOF_CLUSTER, 0,
clu.flags);
+ else
+ hint_femp->cur = clu;
return -ENOSPC;
}
@@ -324,8 +291,9 @@ static int exfat_check_max_dentries(struct inode *inode)
/* find empty directory entry.
* if there isn't any empty slot, expand cluster chain.
*/
-static int exfat_find_empty_entry(struct inode *inode,
- struct exfat_chain *p_dir, int num_entries)
+static int __exfat_find_empty_entry(struct inode *inode,
+ struct exfat_chain *p_dir, int num_entries,
+ struct exfat_entry_set_cache *es)
{
int dentry;
unsigned int ret, last_clu;
@@ -344,7 +312,7 @@ static int exfat_find_empty_entry(struct inode *inode,
}
while ((dentry = exfat_search_empty_slot(sb, &hint_femp, p_dir,
- num_entries)) < 0) {
+ num_entries, es)) < 0) {
if (dentry == -EIO)
break;
@@ -414,6 +382,21 @@ static int exfat_find_empty_entry(struct inode *inode,
return dentry;
}
+static int exfat_find_empty_entry(struct inode *inode,
+ struct exfat_chain *p_dir, int num_entries)
+{
+ int entry;
+ struct exfat_entry_set_cache es;
+
+ entry = __exfat_find_empty_entry(inode, p_dir, num_entries, &es);
+ if (entry < 0)
+ return entry;
+
+ exfat_put_dentry_set(&es, false);
+
+ return entry;
+}
+
/*
* Name Resolution Functions :
* Zero if it was successful; otherwise nonzero.
--
2.25.1
