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-rw-r--r--include/linux/fs.h19
1 files changed, 17 insertions, 2 deletions
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 *);