[PATCH v2 2/2] exfat: aggregate dir-entry updates into __exfat_write_inode().

From: Tetsuhiro Kohada
Date: Sat Sep 19 2020 - 19:58:52 EST

The following function writes the updated inode information as dir-entry
by themselves.
- __exfat_truncate()
- exfat_map_cluster()
- exfat_find_empty_entry()
Aggregate these writes into __exfat_write_inode().

Also, in __exfat_write_inode(), rename 'on_disk_size' to 'filesize' and
add adjustment when filesize is 0.

Reported-by: kernel test robot <lkp@xxxxxxxxx>
Signed-off-by: Tetsuhiro Kohada <kohada.t2@xxxxxxxxx>
---
Changes in v2
- Fix endian issue

fs/exfat/file.c | 49 +++++-------------------------------------------
fs/exfat/inode.c | 42 +++++++++++------------------------------
fs/exfat/namei.c | 26 +++++--------------------
3 files changed, 21 insertions(+), 96 deletions(-)

diff --git a/fs/exfat/file.c b/fs/exfat/file.c
index dcc99349b816..d5b026183387 100644
--- a/fs/exfat/file.c
+++ b/fs/exfat/file.c
@@ -100,7 +100,7 @@ int __exfat_truncate(struct inode *inode, loff_t new_size)
struct super_block *sb = inode->i_sb;
struct exfat_sb_info *sbi = EXFAT_SB(sb);
struct exfat_inode_info *ei = EXFAT_I(inode);
- int evict = (ei->dir.dir == DIR_DELETED) ? 1 : 0;
+ int ret;

/* check if the given file ID is opened */
if (ei->type != TYPE_FILE && ei->type != TYPE_DIR)
@@ -150,49 +150,10 @@ int __exfat_truncate(struct inode *inode, loff_t new_size)
ei->attr |= ATTR_ARCHIVE;

/* update the directory entry */
- if (!evict) {
- struct timespec64 ts;
- struct exfat_dentry *ep, *ep2;
- struct exfat_entry_set_cache *es;
- int err;
-
- es = exfat_get_dentry_set(sb, &(ei->dir), ei->entry,
- ES_ALL_ENTRIES);
- if (!es)
- return -EIO;
- ep = exfat_get_dentry_cached(es, 0);
- ep2 = exfat_get_dentry_cached(es, 1);
-
- ts = current_time(inode);
- exfat_set_entry_time(sbi, &ts,
- &ep->dentry.file.modify_tz,
- &ep->dentry.file.modify_time,
- &ep->dentry.file.modify_date,
- &ep->dentry.file.modify_time_cs);
- ep->dentry.file.attr = cpu_to_le16(ei->attr);
-
- /* File size should be zero if there is no cluster allocated */
- if (ei->start_clu == EXFAT_EOF_CLUSTER) {
- ep2->dentry.stream.valid_size = 0;
- ep2->dentry.stream.size = 0;
- } else {
- ep2->dentry.stream.valid_size = cpu_to_le64(new_size);
- ep2->dentry.stream.size = ep2->dentry.stream.valid_size;
- }
-
- if (new_size == 0) {
- /* Any directory can not be truncated to zero */
- WARN_ON(ei->type != TYPE_FILE);
-
- ep2->dentry.stream.flags = ALLOC_FAT_CHAIN;
- ep2->dentry.stream.start_clu = EXFAT_FREE_CLUSTER;
- }
-
- exfat_update_dir_chksum_with_entry_set(es);
- err = exfat_free_dentry_set(es, inode_needs_sync(inode));
- if (err)
- return err;
- }
+ inode->i_mtime = current_time(inode);
+ ret = exfat_update_inode(inode);
+ if (ret)
+ return ret;

/* cut off from the FAT chain */
if (ei->flags == ALLOC_FAT_CHAIN && last_clu != EXFAT_FREE_CLUSTER &&
diff --git a/fs/exfat/inode.c b/fs/exfat/inode.c
index f307019afe88..74e105e95942 100644
--- a/fs/exfat/inode.c
+++ b/fs/exfat/inode.c
@@ -19,7 +19,7 @@

static int __exfat_write_inode(struct inode *inode, int sync)
{
- unsigned long long on_disk_size;
+ unsigned long long filesize;
struct exfat_dentry *ep, *ep2;
struct exfat_entry_set_cache *es = NULL;
struct super_block *sb = inode->i_sb;
@@ -68,13 +68,14 @@ static int __exfat_write_inode(struct inode *inode, int sync)
NULL);

/* File size should be zero if there is no cluster allocated */
- on_disk_size = i_size_read(inode);
-
+ filesize = i_size_read(inode);
if (ei->start_clu == EXFAT_EOF_CLUSTER)
- on_disk_size = 0;
+ filesize = 0;

- ep2->dentry.stream.valid_size = cpu_to_le64(on_disk_size);
+ ep2->dentry.stream.valid_size = cpu_to_le64(filesize);
ep2->dentry.stream.size = ep2->dentry.stream.valid_size;
+ ep2->dentry.stream.flags = filesize ? ei->flags : ALLOC_FAT_CHAIN;
+ ep2->dentry.stream.start_clu = cpu_to_le32(filesize ? ei->start_clu : EXFAT_FREE_CLUSTER);

exfat_update_dir_chksum_with_entry_set(es);
return exfat_free_dentry_set(es, sync);
@@ -223,32 +224,11 @@ static int exfat_map_cluster(struct inode *inode, unsigned int clu_offset,
num_clusters += num_to_be_allocated;
*clu = new_clu.dir;

- if (ei->dir.dir != DIR_DELETED && modified) {
- struct exfat_dentry *ep;
- struct exfat_entry_set_cache *es;
- int err;
-
- es = exfat_get_dentry_set(sb, &(ei->dir), ei->entry,
- ES_ALL_ENTRIES);
- if (!es)
- return -EIO;
- /* get stream entry */
- ep = exfat_get_dentry_cached(es, 1);
-
- /* update directory entry */
- ep->dentry.stream.flags = ei->flags;
- ep->dentry.stream.start_clu =
- cpu_to_le32(ei->start_clu);
- ep->dentry.stream.valid_size =
- cpu_to_le64(i_size_read(inode));
- ep->dentry.stream.size =
- ep->dentry.stream.valid_size;
-
- exfat_update_dir_chksum_with_entry_set(es);
- err = exfat_free_dentry_set(es, inode_needs_sync(inode));
- if (err)
- return err;
- } /* end of if != DIR_DELETED */
+ if (modified) {
+ ret = exfat_update_inode(inode);
+ if (ret)
+ return ret;
+ }

inode->i_blocks +=
num_to_be_allocated << sbi->sect_per_clus_bits;
diff --git a/fs/exfat/namei.c b/fs/exfat/namei.c
index 4febff3541a9..903ad6ca53a2 100644
--- a/fs/exfat/namei.c
+++ b/fs/exfat/namei.c
@@ -306,10 +306,8 @@ static int exfat_find_empty_entry(struct inode *inode,
{
int dentry;
unsigned int ret, last_clu;
- sector_t sector;
loff_t size = 0;
struct exfat_chain clu;
- struct exfat_dentry *ep = NULL;
struct super_block *sb = inode->i_sb;
struct exfat_sb_info *sbi = EXFAT_SB(sb);
struct exfat_inode_info *ei = EXFAT_I(inode);
@@ -375,31 +373,17 @@ static int exfat_find_empty_entry(struct inode *inode,
p_dir->size++;
size = EXFAT_CLU_TO_B(p_dir->size, sbi);

- /* update the directory entry */
- if (p_dir->dir != sbi->root_dir) {
- struct buffer_head *bh;
-
- ep = exfat_get_dentry(sb,
- &(ei->dir), ei->entry + 1, &bh, &sector);
- if (!ep)
- return -EIO;
-
- ep->dentry.stream.valid_size = cpu_to_le64(size);
- ep->dentry.stream.size = ep->dentry.stream.valid_size;
- ep->dentry.stream.flags = p_dir->flags;
- exfat_update_bh(bh, IS_DIRSYNC(inode));
- brelse(bh);
- if (exfat_update_dir_chksum(inode, &(ei->dir),
- ei->entry))
- return -EIO;
- }
-
/* directory inode should be updated in here */
i_size_write(inode, size);
EXFAT_I(inode)->i_size_ondisk += sbi->cluster_size;
EXFAT_I(inode)->i_size_aligned += sbi->cluster_size;
EXFAT_I(inode)->flags = p_dir->flags;
inode->i_blocks += 1 << sbi->sect_per_clus_bits;
+
+ /* update the directory entry */
+ ret = exfat_update_inode(inode);
+ if (ret)
+ return ret;
}

return dentry;
--
2.25.1