diff options
| author | Chi Zhiling <chizhiling@kylinos.cn> | 2026-01-14 20:12:37 +0800 |
|---|---|---|
| committer | Namjae Jeon <linkinjeon@kernel.org> | 2026-02-12 21:21:47 +0900 |
| commit | 967288e9a6f2ca88cf7d004d87bb3aa9db64fbe2 (patch) | |
| tree | cce783d5c37f96cb87230999f3163681cfdd7c02 /fs | |
| parent | 0914882bdda645e10cf536b474631e1a023b67c0 (diff) | |
exfat: add cache option for __exfat_ent_get
When multiple entries are obtained consecutively, these entries are mostly
stored adjacent to each other. this patch introduces a "last" parameter to
cache the last opened buffer head, and reuse it when possible, which
reduces the number of sb_bread() calls.
When the passed parameter "last" is NULL, it means cache option is
disabled, the behavior unchanged as it was.
Signed-off-by: Chi Zhiling <chizhiling@kylinos.cn>
Reviewed-by: Yuezhang Mo <Yuezhang.Mo@sony.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/exfat/fatent.c | 20 |
1 files changed, 13 insertions, 7 deletions
diff --git a/fs/exfat/fatent.c b/fs/exfat/fatent.c index c9c5f2e3a05e..0cfbc0b435bd 100644 --- a/fs/exfat/fatent.c +++ b/fs/exfat/fatent.c @@ -36,18 +36,23 @@ static int exfat_mirror_bh(struct super_block *sb, sector_t sec, } static int __exfat_ent_get(struct super_block *sb, unsigned int loc, - unsigned int *content) + unsigned int *content, struct buffer_head **last) { unsigned int off; sector_t sec; - struct buffer_head *bh; + struct buffer_head *bh = last ? *last : NULL; sec = FAT_ENT_OFFSET_SECTOR(sb, loc); off = FAT_ENT_OFFSET_BYTE_IN_SECTOR(sb, loc); - bh = sb_bread(sb, sec); - if (!bh) - return -EIO; + if (!bh || bh->b_blocknr != sec || !buffer_uptodate(bh)) { + brelse(bh); + bh = sb_bread(sb, sec); + if (last) + *last = bh; + if (unlikely(!bh)) + return -EIO; + } *content = le32_to_cpu(*(__le32 *)(&bh->b_data[off])); @@ -55,7 +60,8 @@ static int __exfat_ent_get(struct super_block *sb, unsigned int loc, if (*content > EXFAT_BAD_CLUSTER) *content = EXFAT_EOF_CLUSTER; - brelse(bh); + if (!last) + brelse(bh); return 0; } @@ -95,7 +101,7 @@ int exfat_ent_get(struct super_block *sb, unsigned int loc, return -EIO; } - err = __exfat_ent_get(sb, loc, content); + err = __exfat_ent_get(sb, loc, content, NULL); if (err) { exfat_fs_error_ratelimit(sb, "failed to access to FAT (entry 0x%08x, err:%d)", |