This will remove every bd_mount_sem use in nilfs.
The intended exclusion control was replaced by the previous patch
("nilfs2: correct exclusion control in nilfs_remount function") for
nilfs_remount(), and this patch will replace remains with a new mutex
that this inserts in nilfs object.
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@xxxxxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxxxxxxxxx>
---
fs/nilfs2/cpfile.c | 6 +++---
fs/nilfs2/super.c | 12 ++++++------
fs/nilfs2/the_nilfs.c | 1 +
fs/nilfs2/the_nilfs.h | 2 ++
4 files changed, 12 insertions(+), 9 deletions(-)
diff --git a/fs/nilfs2/cpfile.c b/fs/nilfs2/cpfile.c
index 300f1cd..cadd36b 100644
--- a/fs/nilfs2/cpfile.c
+++ b/fs/nilfs2/cpfile.c
@@ -864,11 +864,11 @@ int nilfs_cpfile_change_cpmode(struct inode *cpfile, __u64 cno, int mode)
case NILFS_CHECKPOINT:
/*
* Check for protecting existing snapshot mounts:
- * bd_mount_sem is used to make this operation atomic and
+ * ns_mount_mutex is used to make this operation atomic and
* exclusive with a new mount job. Though it doesn't cover
* umount, it's enough for the purpose.
*/
- down(&nilfs->ns_bdev->bd_mount_sem);
+ mutex_lock(&nilfs->ns_mount_mutex);
if (nilfs_checkpoint_is_mounted(nilfs, cno, 1)) {
/* Current implementation does not have to protect
plain read-only mounts since they are exclusive
@@ -877,7 +877,7 @@ int nilfs_cpfile_change_cpmode(struct inode *cpfile, __u64 cno, int mode)
ret = -EBUSY;
} else
ret = nilfs_cpfile_clear_snapshot(cpfile, cno);
- up(&nilfs->ns_bdev->bd_mount_sem);
+ mutex_unlock(&nilfs->ns_mount_mutex);
return ret;
case NILFS_SNAPSHOT:
return nilfs_cpfile_set_snapshot(cpfile, cno);
diff --git a/fs/nilfs2/super.c b/fs/nilfs2/super.c
index aa658c3..1feb588 100644
--- a/fs/nilfs2/super.c
+++ b/fs/nilfs2/super.c
@@ -754,7 +754,7 @@ int nilfs_store_magic_and_option(struct super_block *sb,
* @silent: silent mode flag
* @nilfs: the_nilfs struct
*
- * This function is called exclusively by bd_mount_mutex.
+ * This function is called exclusively by nilfs->ns_mount_mutex.
* So, the recovery process is protected from other simultaneous mounts.
*/
static int
@@ -1091,7 +1091,7 @@ nilfs_get_sb(struct file_system_type *fs_type, int flags,
goto failed;
}
- down(&sd.bdev->bd_mount_sem);
+ mutex_lock(&nilfs->ns_mount_mutex);
if (!sd.cno) {
/*
@@ -1150,7 +1150,7 @@ nilfs_get_sb(struct file_system_type *fs_type, int flags,
need_to_close = 0;
}
- up(&sd.bdev->bd_mount_sem);
+ mutex_unlock(&nilfs->ns_mount_mutex);
put_nilfs(nilfs);
if (need_to_close)
close_bdev_exclusive(sd.bdev, flags);
@@ -1158,7 +1158,7 @@ nilfs_get_sb(struct file_system_type *fs_type, int flags,
return 0;
failed_unlock:
- up(&sd.bdev->bd_mount_sem);
+ mutex_unlock(&nilfs->ns_mount_mutex);
put_nilfs(nilfs);
failed:
close_bdev_exclusive(sd.bdev, flags);
@@ -1167,14 +1167,14 @@ nilfs_get_sb(struct file_system_type *fs_type, int flags,
cancel_new:
/* Abandoning the newly allocated superblock */
- up(&sd.bdev->bd_mount_sem);
+ mutex_unlock(&nilfs->ns_mount_mutex);
put_nilfs(nilfs);
up_write(&s->s_umount);
deactivate_super(s);
/*
* deactivate_super() invokes close_bdev_exclusive().
* We must finish all post-cleaning before this call;
- * put_nilfs() and unlocking bd_mount_sem need the block device.
+ * put_nilfs() needs the block device.
*/
return err;
}
diff --git a/fs/nilfs2/the_nilfs.c b/fs/nilfs2/the_nilfs.c
index fa46320..fdac4db 100644
--- a/fs/nilfs2/the_nilfs.c
+++ b/fs/nilfs2/the_nilfs.c
@@ -73,6 +73,7 @@ static struct the_nilfs *alloc_nilfs(struct block_device *bdev)
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_LIST_HEAD(&nilfs->ns_list);
INIT_LIST_HEAD(&nilfs->ns_supers);
diff --git a/fs/nilfs2/the_nilfs.h b/fs/nilfs2/the_nilfs.h
index d0cf4fb..e8adbff 100644
--- a/fs/nilfs2/the_nilfs.h
+++ b/fs/nilfs2/the_nilfs.h
@@ -49,6 +49,7 @@ enum {
* @ns_writer: back pointer to writable nilfs_sb_info
* @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_current: back pointer to current mount
@@ -98,6 +99,7 @@ struct the_nilfs {
struct nilfs_sb_info *ns_writer;
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;
--
1.6.2
--
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