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-rw-r--r--fs/nilfs2/mdt.c8
-rw-r--r--fs/nilfs2/the_nilfs.c3
-rw-r--r--fs/nilfs2/the_nilfs.h27
3 files changed, 12 insertions, 26 deletions
diff --git a/fs/nilfs2/mdt.c b/fs/nilfs2/mdt.c
index 2dfd47714ae..a5cd80162dc 100644
--- a/fs/nilfs2/mdt.c
+++ b/fs/nilfs2/mdt.c
@@ -402,6 +402,7 @@ nilfs_mdt_write_page(struct page *page, struct writeback_control *wbc)
struct inode *inode = container_of(page->mapping,
struct inode, i_data);
struct super_block *sb = inode->i_sb;
+ struct the_nilfs *nilfs = NILFS_MDT(inode)->mi_nilfs;
struct nilfs_sb_info *writer = NULL;
int err = 0;
@@ -411,9 +412,10 @@ nilfs_mdt_write_page(struct page *page, struct writeback_control *wbc)
if (page->mapping->assoc_mapping)
return 0; /* Do not request flush for shadow page cache */
if (!sb) {
- writer = nilfs_get_writer(NILFS_MDT(inode)->mi_nilfs);
+ down_read(&nilfs->ns_writer_sem);
+ writer = nilfs->ns_writer;
if (!writer) {
- nilfs_put_writer(NILFS_MDT(inode)->mi_nilfs);
+ up_read(&nilfs->ns_writer_sem);
return -EROFS;
}
sb = writer->s_super;
@@ -425,7 +427,7 @@ nilfs_mdt_write_page(struct page *page, struct writeback_control *wbc)
nilfs_flush_segment(sb, inode->i_ino);
if (writer)
- nilfs_put_writer(NILFS_MDT(inode)->mi_nilfs);
+ up_read(&nilfs->ns_writer_sem);
return err;
}
diff --git a/fs/nilfs2/the_nilfs.c b/fs/nilfs2/the_nilfs.c
index 8b888982571..0c4573653b8 100644
--- a/fs/nilfs2/the_nilfs.c
+++ b/fs/nilfs2/the_nilfs.c
@@ -68,12 +68,11 @@ static struct the_nilfs *alloc_nilfs(struct block_device *bdev)
nilfs->ns_bdev = bdev;
atomic_set(&nilfs->ns_count, 1);
- atomic_set(&nilfs->ns_writer_refcount, -1);
atomic_set(&nilfs->ns_ndirtyblks, 0);
init_rwsem(&nilfs->ns_sem);
init_rwsem(&nilfs->ns_super_sem);
mutex_init(&nilfs->ns_mount_mutex);
- mutex_init(&nilfs->ns_writer_mutex);
+ init_rwsem(&nilfs->ns_writer_sem);
INIT_LIST_HEAD(&nilfs->ns_list);
INIT_LIST_HEAD(&nilfs->ns_supers);
spin_lock_init(&nilfs->ns_last_segment_lock);
diff --git a/fs/nilfs2/the_nilfs.h b/fs/nilfs2/the_nilfs.h
index 1b9caafb866..fa3a1dfe405 100644
--- a/fs/nilfs2/the_nilfs.h
+++ b/fs/nilfs2/the_nilfs.h
@@ -50,8 +50,7 @@ enum {
* @ns_sem: semaphore for shared states
* @ns_super_sem: semaphore for global operations across super block instances
* @ns_mount_mutex: mutex protecting mount process of nilfs
- * @ns_writer_mutex: mutex protecting ns_writer attach/detach
- * @ns_writer_refcount: number of referrers on ns_writer
+ * @ns_writer_sem: semaphore protecting ns_writer attach/detach
* @ns_current: back pointer to current mount
* @ns_sbh: buffer heads of on-disk super blocks
* @ns_sbp: pointers to super block data
@@ -100,8 +99,7 @@ struct the_nilfs {
struct rw_semaphore ns_sem;
struct rw_semaphore ns_super_sem;
struct mutex ns_mount_mutex;
- struct mutex ns_writer_mutex;
- atomic_t ns_writer_refcount;
+ struct rw_semaphore ns_writer_sem;
/*
* components protected by ns_super_sem
@@ -221,34 +219,21 @@ static inline void get_nilfs(struct the_nilfs *nilfs)
atomic_inc(&nilfs->ns_count);
}
-static inline struct nilfs_sb_info *nilfs_get_writer(struct the_nilfs *nilfs)
-{
- if (atomic_inc_and_test(&nilfs->ns_writer_refcount))
- mutex_lock(&nilfs->ns_writer_mutex);
- return nilfs->ns_writer;
-}
-
-static inline void nilfs_put_writer(struct the_nilfs *nilfs)
-{
- if (atomic_add_negative(-1, &nilfs->ns_writer_refcount))
- mutex_unlock(&nilfs->ns_writer_mutex);
-}
-
static inline void
nilfs_attach_writer(struct the_nilfs *nilfs, struct nilfs_sb_info *sbi)
{
- mutex_lock(&nilfs->ns_writer_mutex);
+ down_write(&nilfs->ns_writer_sem);
nilfs->ns_writer = sbi;
- mutex_unlock(&nilfs->ns_writer_mutex);
+ up_write(&nilfs->ns_writer_sem);
}
static inline void
nilfs_detach_writer(struct the_nilfs *nilfs, struct nilfs_sb_info *sbi)
{
- mutex_lock(&nilfs->ns_writer_mutex);
+ down_write(&nilfs->ns_writer_sem);
if (sbi == nilfs->ns_writer)
nilfs->ns_writer = NULL;
- mutex_unlock(&nilfs->ns_writer_mutex);
+ up_write(&nilfs->ns_writer_sem);
}
static inline void nilfs_put_sbinfo(struct nilfs_sb_info *sbi)