summaryrefslogtreecommitdiff
path: root/include
diff options
context:
space:
mode:
Diffstat (limited to 'include')
-rw-r--r--include/linux/blk_types.h8
-rw-r--r--include/linux/blkdev.h29
-rw-r--r--include/linux/fs.h19
3 files changed, 41 insertions, 15 deletions
diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index b29ebd53417d..7c2316c91cbd 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -57,20 +57,18 @@ struct block_device {
void * bd_holder;
const struct blk_holder_ops *bd_holder_ops;
struct mutex bd_holder_lock;
- /* The counter of freeze processes */
- int bd_fsfreeze_count;
int bd_holders;
struct kobject *bd_holder_dir;
- /* Mutex for freeze */
- struct mutex bd_fsfreeze_mutex;
- struct super_block *bd_fsfreeze_sb;
+ atomic_t bd_fsfreeze_count; /* number of freeze requests */
+ struct mutex bd_fsfreeze_mutex; /* serialize freeze/thaw */
struct partition_meta_info *bd_meta_info;
#ifdef CONFIG_FAIL_MAKE_REQUEST
bool bd_make_it_fail;
#endif
bool bd_ro_warned;
+ int bd_writers;
/*
* keep this out-of-line as it's both big and not needed in the fast
* path
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 88e9dd4b71fb..c30a98e08423 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -124,6 +124,8 @@ typedef unsigned int __bitwise blk_mode_t;
#define BLK_OPEN_NDELAY ((__force blk_mode_t)(1 << 3))
/* open for "writes" only for ioctls (specialy hack for floppy.c) */
#define BLK_OPEN_WRITE_IOCTL ((__force blk_mode_t)(1 << 4))
+/* open is exclusive wrt all other BLK_OPEN_WRITE opens to the device */
+#define BLK_OPEN_RESTRICT_WRITES ((__force blk_mode_t)(1 << 5))
struct gendisk {
/*
@@ -1468,8 +1470,23 @@ struct blk_holder_ops {
* Sync the file system mounted on the block device.
*/
void (*sync)(struct block_device *bdev);
+
+ /*
+ * Freeze the file system mounted on the block device.
+ */
+ int (*freeze)(struct block_device *bdev);
+
+ /*
+ * Thaw the file system mounted on the block device.
+ */
+ int (*thaw)(struct block_device *bdev);
};
+/*
+ * For filesystems using @fs_holder_ops, the @holder argument passed to
+ * helpers used to open and claim block devices via
+ * bd_prepare_to_claim() must point to a superblock.
+ */
extern const struct blk_holder_ops fs_holder_ops;
/*
@@ -1477,7 +1494,8 @@ extern const struct blk_holder_ops fs_holder_ops;
* as stored in sb->s_flags.
*/
#define sb_open_mode(flags) \
- (BLK_OPEN_READ | (((flags) & SB_RDONLY) ? 0 : BLK_OPEN_WRITE))
+ (BLK_OPEN_READ | BLK_OPEN_RESTRICT_WRITES | \
+ (((flags) & SB_RDONLY) ? 0 : BLK_OPEN_WRITE))
struct bdev_handle {
struct block_device *bdev;
@@ -1485,10 +1503,6 @@ struct bdev_handle {
blk_mode_t mode;
};
-struct block_device *blkdev_get_by_dev(dev_t dev, blk_mode_t mode, void *holder,
- const struct blk_holder_ops *hops);
-struct block_device *blkdev_get_by_path(const char *path, blk_mode_t mode,
- void *holder, const struct blk_holder_ops *hops);
struct bdev_handle *bdev_open_by_dev(dev_t dev, blk_mode_t mode, void *holder,
const struct blk_holder_ops *hops);
struct bdev_handle *bdev_open_by_path(const char *path, blk_mode_t mode,
@@ -1496,7 +1510,6 @@ struct bdev_handle *bdev_open_by_path(const char *path, blk_mode_t mode,
int bd_prepare_to_claim(struct block_device *bdev, void *holder,
const struct blk_holder_ops *hops);
void bd_abort_claiming(struct block_device *bdev, void *holder);
-void blkdev_put(struct block_device *bdev, void *holder);
void bdev_release(struct bdev_handle *handle);
/* just for blk-cgroup, don't use elsewhere */
@@ -1541,8 +1554,8 @@ static inline int early_lookup_bdev(const char *pathname, dev_t *dev)
}
#endif /* CONFIG_BLOCK */
-int freeze_bdev(struct block_device *bdev);
-int thaw_bdev(struct block_device *bdev);
+int bdev_freeze(struct block_device *bdev);
+int bdev_thaw(struct block_device *bdev);
struct io_comp_batch {
struct request *req_list;
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 3d58376ed39e..7e7399bd8bc5 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1187,7 +1187,8 @@ enum {
struct sb_writers {
unsigned short frozen; /* Is sb frozen? */
- unsigned short freeze_holders; /* Who froze fs? */
+ int freeze_kcount; /* How many kernel freeze requests? */
+ int freeze_ucount; /* How many userspace freeze requests? */
struct percpu_rw_semaphore rw_sem[SB_FREEZE_LEVELS];
};
@@ -2053,9 +2054,24 @@ extern loff_t vfs_dedupe_file_range_one(struct file *src_file, loff_t src_pos,
struct file *dst_file, loff_t dst_pos,
loff_t len, unsigned int remap_flags);
+/**
+ * enum freeze_holder - holder of the freeze
+ * @FREEZE_HOLDER_KERNEL: kernel wants to freeze or thaw filesystem
+ * @FREEZE_HOLDER_USERSPACE: userspace wants to freeze or thaw filesystem
+ * @FREEZE_MAY_NEST: whether nesting freeze and thaw requests is allowed
+ *
+ * Indicate who the owner of the freeze or thaw request is and whether
+ * the freeze needs to be exclusive or can nest.
+ * Without @FREEZE_MAY_NEST, multiple freeze and thaw requests from the
+ * same holder aren't allowed. It is however allowed to hold a single
+ * @FREEZE_HOLDER_USERSPACE and a single @FREEZE_HOLDER_KERNEL freeze at
+ * the same time. This is relied upon by some filesystems during online
+ * repair or similar.
+ */
enum freeze_holder {
FREEZE_HOLDER_KERNEL = (1U << 0),
FREEZE_HOLDER_USERSPACE = (1U << 1),
+ FREEZE_MAY_NEST = (1U << 2),
};
struct super_operations {
@@ -3131,7 +3147,6 @@ extern int vfs_readlink(struct dentry *, char __user *, int);
extern struct file_system_type *get_filesystem(struct file_system_type *fs);
extern void put_filesystem(struct file_system_type *fs);
extern struct file_system_type *get_fs_type(const char *name);
-extern struct super_block *get_active_super(struct block_device *bdev);
extern void drop_super(struct super_block *sb);
extern void drop_super_exclusive(struct super_block *sb);
extern void iterate_supers(void (*)(struct super_block *, void *), void *);