filesystem freeze: implement generic freeze feature

[linux-2.6-omap-h63xx.git] / include / linux / fs.h

diff --git a/include/linux/fs.h b/include/linux/fs.h
index fb59673c60b1bee2b71d123494e395da7068e2a4..6022f44043f2a01305bb09564c82d78bd08ad006 100644 (file)
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -234,6 +234,8 @@ struct inodes_stat_t {
 #define BMAP_IOCTL 1           /* obsolete - kept for compatibility */
 #define FIBMAP    _IO(0x00,1)  /* bmap access */
 #define FIGETBSZ   _IO(0x00,2) /* get the block size used for bmap */
+#define FIFREEZE       _IOWR('X', 119, int)    /* Freeze */
+#define FITHAW         _IOWR('X', 120, int)    /* Thaw */
 
 #define        FS_IOC_GETFLAGS                 _IOR('f', 1, long)
 #define        FS_IOC_SETFLAGS                 _IOW('f', 2, long)
@@ -565,6 +567,7 @@ struct address_space {
 struct block_device {
        dev_t                   bd_dev;  /* not a kdev_t - it's a search key */
        struct inode *          bd_inode;       /* will die */
+       struct super_block *    bd_super;
        int                     bd_openers;
        struct mutex            bd_mutex;       /* open/close mutex */
        struct semaphore        bd_mount_sem;
@@ -590,6 +593,11 @@ struct block_device {
         * care to not mess up bd_private for that case.
         */
        unsigned long           bd_private;
+
+       /* The counter of freeze processes */
+       int                     bd_fsfreeze_count;
+       /* Mutex for freeze */
+       struct mutex            bd_fsfreeze_mutex;
 };
 
 /*
@@ -1133,7 +1141,6 @@ struct super_block {
        struct rw_semaphore     s_umount;
        struct mutex            s_lock;
        int                     s_count;
-       int                     s_syncing;
        int                     s_need_sync_fs;
        atomic_t                s_active;
 #ifdef CONFIG_SECURITY
@@ -1185,6 +1192,11 @@ struct super_block {
         * generic_show_options()
         */
        char *s_options;
+
+       /*
+        * storage for asynchronous operations
+        */
+       struct list_head s_async_list;
 };
 
 extern struct timespec current_fs_time(struct super_block *sb);
@@ -1372,8 +1384,8 @@ struct super_operations {
        void (*put_super) (struct super_block *);
        void (*write_super) (struct super_block *);
        int (*sync_fs)(struct super_block *sb, int wait);
-       void (*write_super_lockfs) (struct super_block *);
-       void (*unlockfs) (struct super_block *);
+       int (*freeze_fs) (struct super_block *);
+       int (*unfreeze_fs) (struct super_block *);
        int (*statfs) (struct dentry *, struct kstatfs *);
        int (*remount_fs) (struct super_block *, int *, char *);
        void (*clear_inode) (struct inode *);
@@ -1385,6 +1397,7 @@ struct super_operations {
        ssize_t (*quota_read)(struct super_block *, int, char *, size_t, loff_t);
        ssize_t (*quota_write)(struct super_block *, int, const char *, size_t, loff_t);
 #endif
+       int (*bdev_try_to_free_page)(struct super_block*, struct page*, gfp_t);
 };
 
 /*