From: Hyeongseok Kim <hyeongseok@gmail.com>
To: namjae.jeon@samsung.com, sj1557.seo@samsung.com
Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
Hyeongseok Kim <hyeongseok@gmail.com>
Subject: [PATCH v4 1/2] exfat: introduce bitmap_lock for cluster bitmap access
Date: Tue, 2 Mar 2021 14:05:20 +0900 [thread overview]
Message-ID: <20210302050521.6059-2-hyeongseok@gmail.com> (raw)
In-Reply-To: <20210302050521.6059-1-hyeongseok@gmail.com>
s_lock which is for protecting concurrent access of file operations is
too huge for cluster bitmap protection, so introduce a new bitmap_lock
to narrow the lock range if only need to access cluster bitmap.
Signed-off-by: Hyeongseok Kim <hyeongseok@gmail.com>
---
fs/exfat/exfat_fs.h | 1 +
fs/exfat/fatent.c | 37 +++++++++++++++++++++++++++++--------
fs/exfat/super.c | 1 +
3 files changed, 31 insertions(+), 8 deletions(-)
diff --git a/fs/exfat/exfat_fs.h b/fs/exfat/exfat_fs.h
index 764bc645241e..1ce422d7e9ae 100644
--- a/fs/exfat/exfat_fs.h
+++ b/fs/exfat/exfat_fs.h
@@ -238,6 +238,7 @@ struct exfat_sb_info {
unsigned int used_clusters; /* number of used clusters */
struct mutex s_lock; /* superblock lock */
+ struct mutex bitmap_lock; /* bitmap lock */
struct exfat_mount_options options;
struct nls_table *nls_io; /* Charset used for input and display */
struct ratelimit_state ratelimit;
diff --git a/fs/exfat/fatent.c b/fs/exfat/fatent.c
index 7b2e8af17193..fd6c7fd12762 100644
--- a/fs/exfat/fatent.c
+++ b/fs/exfat/fatent.c
@@ -151,13 +151,14 @@ int exfat_chain_cont_cluster(struct super_block *sb, unsigned int chain,
return 0;
}
-int exfat_free_cluster(struct inode *inode, struct exfat_chain *p_chain)
+/* This function must be called with bitmap_lock held */
+static int __exfat_free_cluster(struct inode *inode, struct exfat_chain *p_chain)
{
- unsigned int num_clusters = 0;
- unsigned int clu;
struct super_block *sb = inode->i_sb;
struct exfat_sb_info *sbi = EXFAT_SB(sb);
int cur_cmap_i, next_cmap_i;
+ unsigned int num_clusters = 0;
+ unsigned int clu;
/* invalid cluster number */
if (p_chain->dir == EXFAT_FREE_CLUSTER ||
@@ -230,6 +231,17 @@ int exfat_free_cluster(struct inode *inode, struct exfat_chain *p_chain)
return 0;
}
+int exfat_free_cluster(struct inode *inode, struct exfat_chain *p_chain)
+{
+ int ret = 0;
+
+ mutex_lock(&EXFAT_SB(inode->i_sb)->bitmap_lock);
+ ret = __exfat_free_cluster(inode, p_chain);
+ mutex_unlock(&EXFAT_SB(inode->i_sb)->bitmap_lock);
+
+ return ret;
+}
+
int exfat_find_last_cluster(struct super_block *sb, struct exfat_chain *p_chain,
unsigned int *ret_clu)
{
@@ -328,6 +340,8 @@ int exfat_alloc_cluster(struct inode *inode, unsigned int num_alloc,
if (num_alloc > total_cnt - sbi->used_clusters)
return -ENOSPC;
+ mutex_lock(&sbi->bitmap_lock);
+
hint_clu = p_chain->dir;
/* find new cluster */
if (hint_clu == EXFAT_EOF_CLUSTER) {
@@ -338,8 +352,10 @@ int exfat_alloc_cluster(struct inode *inode, unsigned int num_alloc,
}
hint_clu = exfat_find_free_bitmap(sb, sbi->clu_srch_ptr);
- if (hint_clu == EXFAT_EOF_CLUSTER)
- return -ENOSPC;
+ if (hint_clu == EXFAT_EOF_CLUSTER) {
+ ret = -ENOSPC;
+ goto unlock;
+ }
}
/* check cluster validation */
@@ -349,8 +365,10 @@ int exfat_alloc_cluster(struct inode *inode, unsigned int num_alloc,
hint_clu = EXFAT_FIRST_CLUSTER;
if (p_chain->flags == ALLOC_NO_FAT_CHAIN) {
if (exfat_chain_cont_cluster(sb, p_chain->dir,
- num_clusters))
- return -EIO;
+ num_clusters)) {
+ ret = -EIO;
+ goto unlock;
+ }
p_chain->flags = ALLOC_FAT_CHAIN;
}
}
@@ -400,6 +418,7 @@ int exfat_alloc_cluster(struct inode *inode, unsigned int num_alloc,
sbi->used_clusters += num_clusters;
p_chain->size += num_clusters;
+ mutex_unlock(&sbi->bitmap_lock);
return 0;
}
@@ -419,7 +438,9 @@ int exfat_alloc_cluster(struct inode *inode, unsigned int num_alloc,
}
free_cluster:
if (num_clusters)
- exfat_free_cluster(inode, p_chain);
+ __exfat_free_cluster(inode, p_chain);
+unlock:
+ mutex_unlock(&sbi->bitmap_lock);
return ret;
}
diff --git a/fs/exfat/super.c b/fs/exfat/super.c
index c6d8d2e53486..d38d17a77e76 100644
--- a/fs/exfat/super.c
+++ b/fs/exfat/super.c
@@ -752,6 +752,7 @@ static int exfat_init_fs_context(struct fs_context *fc)
return -ENOMEM;
mutex_init(&sbi->s_lock);
+ mutex_init(&sbi->bitmap_lock);
ratelimit_state_init(&sbi->ratelimit, DEFAULT_RATELIMIT_INTERVAL,
DEFAULT_RATELIMIT_BURST);
--
2.27.0.83.g0313f36
next prev parent reply other threads:[~2021-03-02 8:21 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CGME20210302050548epcas1p2ccec84f5de16f0971fc0479abe64ec3e@epcas1p2.samsung.com>
2021-03-02 5:05 ` [PATCH v4 0/2] Add FITRIM ioctl support for exFAT filesystem Hyeongseok Kim
2021-03-02 5:05 ` Hyeongseok Kim [this message]
2021-03-02 6:54 ` [PATCH v4 1/2] exfat: introduce bitmap_lock for cluster bitmap access Sungjong Seo
2021-03-02 5:05 ` [PATCH v4 2/2] exfat: add support ioctl and FITRIM function Hyeongseok Kim
2021-03-02 6:58 ` Sungjong Seo
2021-03-04 3:43 ` [PATCH v4 0/2] Add FITRIM ioctl support for exFAT filesystem Namjae Jeon
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