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| author |   Hyeongseok Kim <hyeongseok@gmail.com> | 2021-03-22 12:53:36 +0900 |
|---|---|---|
| committer |   Namjae Jeon <namjae.jeon@samsung.com> | 2021-04-27 20:45:07 +0900 |
| commit | c6e2f52e3051e8d898d38840104638ca8bbcdec2 (patch) | |
| tree | 8eb871698cb312d75d7fb56ab582b7ddb133b102 /fs/exfat/namei.c | |
| parent | exfat: improve write performance when dirsync enabled (diff) | |
| download | linux-dev-c6e2f52e3051e8d898d38840104638ca8bbcdec2.tar.xz linux-dev-c6e2f52e3051e8d898d38840104638ca8bbcdec2.zip | |
exfat: speed up iterate/lookup by fixing start point of traversing cluster chain
When directory iterate and lookup is called, there's a buggy rewinding
of start point for traversing cluster chain to the parent directory
entry's first cluster. This caused repeated cluster chain traversing
from the first entry of the parent directory that would show worse
performance if huge amounts of files exist under the parent directory.
Fix not to rewind, make continue from currently referenced cluster and
dir entry.
Tested with 50,000 files under single directory / 256GB sdcard,
with command "time ls -l > /dev/null",
Before : 0m08.69s real 0m00.27s user 0m05.91s system
After : 0m07.01s real 0m00.25s user 0m04.34s system
Signed-off-by: Hyeongseok Kim <hyeongseok@gmail.com>
Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Diffstat (limited to 'fs/exfat/namei.c')
| -rw-r--r-- | fs/exfat/namei.c | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/fs/exfat/namei.c b/fs/exfat/namei.c index 1f7b3dc66fcd..24b41103d1cc 100644 --- a/fs/exfat/namei.c +++ b/fs/exfat/namei.c @@ -596,6 +596,8 @@ static int exfat_find(struct inode *dir, struct qstr *qname, struct exfat_inode_info *ei = EXFAT_I(dir); struct exfat_dentry *ep, *ep2; struct exfat_entry_set_cache *es; + /* for optimized dir & entry to prevent long traverse of cluster chain */ + struct exfat_hint hint_opt; if (qname->len == 0) return -ENOENT; @@ -619,7 +621,7 @@ static int exfat_find(struct inode *dir, struct qstr *qname, /* search the file name for directories */ dentry = exfat_find_dir_entry(sb, ei, &cdir, &uni_name, - num_entries, TYPE_ALL); + num_entries, TYPE_ALL, &hint_opt); if (dentry < 0) return dentry; /* -error value */ @@ -628,6 +630,11 @@ static int exfat_find(struct inode *dir, struct qstr *qname, info->entry = dentry; info->num_subdirs = 0; + /* adjust cdir to the optimized value */ + cdir.dir = hint_opt.clu; + if (cdir.flags & ALLOC_NO_FAT_CHAIN) + cdir.size -= dentry / sbi->dentries_per_clu; + dentry = hint_opt.eidx; es = exfat_get_dentry_set(sb, &cdir, dentry, ES_2_ENTRIES); if (!es) return -EIO; |