diff options
| -rw-r--r-- | fs/nilfs2/mdt.c | 8 | ||||
| -rw-r--r-- | fs/nilfs2/the_nilfs.c | 3 | ||||
| -rw-r--r-- | fs/nilfs2/the_nilfs.h | 27 |
3 files changed, 12 insertions, 26 deletions
diff --git a/fs/nilfs2/mdt.c b/fs/nilfs2/mdt.c index 2dfd47714ae5..a5cd80162dc5 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 8b8889825716..0c4573653b87 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 1b9caafb8662..fa3a1dfe4053 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) |