[PATCH v4 5/5] exfat: write only modified part of dir-entry set

Tetsuhiro Kohada
2020-08-26T11:58:47Z

Currently exfat_free_dentry_set() writes all of dir-entry set.
Change it to write only the modified part of dir-entry set.
And, Integrate exfat_free_dentry_set() and
exfat_update_dir_chksum_with_entry_set() as exfat_put_dentry_set().

Signed-off-by: Tetsuhiro Kohada <kohada.t2@gmail.com>
---
Changes in v2
- Based on v2 'name-length' patches
Changes in v3:
- Nothing
Changes in v4:
- Into patch series '[PATCH v4] exfat: integrates dir-entry getting and validation'

fs/exfat/dir.c | 31 +++++++++++++++----------------
fs/exfat/exfat_fs.h | 4 +---
fs/exfat/file.c | 3 +--
fs/exfat/inode.c | 6 ++----
fs/exfat/namei.c | 4 ++--
5 files changed, 21 insertions(+), 27 deletions(-)

diff --git a/fs/exfat/dir.c b/fs/exfat/dir.c
index d4beea796708..78539d91d3c5 100644
--- a/fs/exfat/dir.c
+++ b/fs/exfat/dir.c
@@ -129,7 +129,7 @@ static int exfat_readdir(struct inode *inode, struct exfat_dir_entry *dir_entry)
dir_entry->size = le64_to_cpu(ES_STREAM(es).valid_size);

err = exfat_get_uniname_from_name_entries(es, &uni_name);
- exfat_free_dentry_set(es, false);
+ exfat_put_dentry_set(es, 0, false);
if (err)
return err;

@@ -580,21 +580,21 @@ static int exfat_calc_entry_set_chksum(struct exfat_entry_set_cache *es, u16 *ch
return 0;
}

-void exfat_update_dir_chksum_with_entry_set(struct exfat_entry_set_cache *es)
-{
- u16 chksum;
-
- exfat_calc_entry_set_chksum(es, &chksum);
- ES_FILE(es).checksum = cpu_to_le16(chksum);
- es->modified = true;
-}
-
-int exfat_free_dentry_set(struct exfat_entry_set_cache *es, int sync)
+int exfat_put_dentry_set(struct exfat_entry_set_cache *es, int modified, int sync)
{
int i, err = 0;

- if (es->modified)
- err = exfat_update_bhs(es->bh, es->num_bh, sync);
+ if (modified) {
+ int off = es->start_off + (modified - 1) * DENTRY_SIZE;
+ int modified_bh = min(EXFAT_B_TO_BLK(off, es->sb) + 1, es->num_bh);
+ u16 chksum;
+
+ err = exfat_calc_entry_set_chksum(es, &chksum);
+ if (!err) {
+ ES_FILE(es).checksum = cpu_to_le16(chksum);
+ err = exfat_update_bhs(es->bh, modified_bh, sync);
+ }
+ }

for (i = 0; i < es->num_bh; i++)
if (err)
@@ -800,7 +800,6 @@ struct exfat_entry_set_cache *exfat_get_dentry_set(struct super_block *sb,
if (!es)
return NULL;
es->sb = sb;
- es->modified = false;
es->num_entries = 1;

/* byte offset in cluster */
@@ -861,7 +860,7 @@ struct exfat_entry_set_cache *exfat_get_dentry_set(struct super_block *sb,
return es;

free_es:
- exfat_free_dentry_set(es, false);
+ exfat_put_dentry_set(es, 0, false);
return NULL;
}

@@ -973,7 +972,7 @@ int exfat_find_dir_entry(struct super_block *sb, struct exfat_inode_info *ei,
!exfat_get_uniname_from_name_entries(es, &uni_name) &&
!exfat_uniname_ncmp(sb, p_uniname->name, uni_name.name, name_len);

- exfat_free_dentry_set(es, false);
+ exfat_put_dentry_set(es, 0, false);

if (found) {
/* set the last used position as hint */
diff --git a/fs/exfat/exfat_fs.h b/fs/exfat/exfat_fs.h
index 7057e64b405d..3354512629ac 100644
--- a/fs/exfat/exfat_fs.h
+++ b/fs/exfat/exfat_fs.h
@@ -170,7 +170,6 @@ struct exfat_hint {

struct exfat_entry_set_cache {
struct super_block *sb;
- bool modified;
unsigned int start_off;
int num_bh;
struct buffer_head *bh[DIR_CACHE_SIZE];
@@ -454,7 +453,6 @@ int exfat_remove_entries(struct inode *inode, struct exfat_chain *p_dir,
int entry, int order, int num_entries);
int exfat_update_dir_chksum(struct inode *inode, struct exfat_chain *p_dir,
int entry);
-void exfat_update_dir_chksum_with_entry_set(struct exfat_entry_set_cache *es);
int exfat_calc_num_entries(struct exfat_uni_name *p_uniname);
int exfat_find_dir_entry(struct super_block *sb, struct exfat_inode_info *ei,
struct exfat_chain *p_dir, struct exfat_uni_name *p_uniname,
@@ -469,7 +467,7 @@ struct exfat_dentry *exfat_get_validated_dentry(struct exfat_entry_set_cache *es
int num, unsigned int type);
struct exfat_entry_set_cache *exfat_get_dentry_set(struct super_block *sb,
struct exfat_chain *p_dir, int entry, int max_entries);
-int exfat_free_dentry_set(struct exfat_entry_set_cache *es, int sync);
+int exfat_put_dentry_set(struct exfat_entry_set_cache *es, int modified, int sync);
int exfat_count_dir_entries(struct super_block *sb, struct exfat_chain *p_dir);

/* inode.c */
diff --git a/fs/exfat/file.c b/fs/exfat/file.c
index 504ffcaffacc..d2b727effb69 100644
--- a/fs/exfat/file.c
+++ b/fs/exfat/file.c
@@ -185,8 +185,7 @@ int __exfat_truncate(struct inode *inode, loff_t new_size)
ES_STREAM(es).start_clu = EXFAT_FREE_CLUSTER;
}

- exfat_update_dir_chksum_with_entry_set(es);
- err = exfat_free_dentry_set(es, inode_needs_sync(inode));
+ err = exfat_put_dentry_set(es, 2, inode_needs_sync(inode));
if (err)
return err;
}
diff --git a/fs/exfat/inode.c b/fs/exfat/inode.c
index 466f0bf07f75..d587c7e02b35 100644
--- a/fs/exfat/inode.c
+++ b/fs/exfat/inode.c
@@ -73,8 +73,7 @@ static int __exfat_write_inode(struct inode *inode, int sync)
ES_STREAM(es).valid_size = cpu_to_le64(on_disk_size);
ES_STREAM(es).size = ES_STREAM(es).valid_size;

- exfat_update_dir_chksum_with_entry_set(es);
- return exfat_free_dentry_set(es, sync);
+ return exfat_put_dentry_set(es, 2, sync);
}

int exfat_write_inode(struct inode *inode, struct writeback_control *wbc)
@@ -230,8 +229,7 @@ static int exfat_map_cluster(struct inode *inode, unsigned int clu_offset,
ES_STREAM(es).valid_size = cpu_to_le64(i_size_read(inode));
ES_STREAM(es).size = ES_STREAM(es).valid_size;

- exfat_update_dir_chksum_with_entry_set(es);
- err = exfat_free_dentry_set(es, inode_needs_sync(inode));
+ err = exfat_put_dentry_set(es, 2, inode_needs_sync(inode));
if (err)
return err;
} /* end of if != DIR_DELETED */
diff --git a/fs/exfat/namei.c b/fs/exfat/namei.c
index d2b9044d0b31..283650825115 100644
--- a/fs/exfat/namei.c
+++ b/fs/exfat/namei.c
@@ -677,7 +677,7 @@ static int exfat_find(struct inode *dir, struct qstr *qname,
exfat_fs_error(sb,
"non-zero size file starts with zero cluster (size : %llu, p_dir : %u, entry : 0x%08x)",
i_size_read(dir), ei->dir.dir, ei->entry);
- exfat_free_dentry_set(es, false);
+ exfat_put_dentry_set(es, 0, false);
return -EIO;
}

@@ -696,7 +696,7 @@ static int exfat_find(struct inode *dir, struct qstr *qname,
ES_FILE(es).access_time,
ES_FILE(es).access_date,
0);
- exfat_free_dentry_set(es, false);
+ exfat_put_dentry_set(es, 0, false);

if (info->type == TYPE_DIR) {
exfat_chain_set(&cdir, info->start_clu,
--
2.25.1