consolidate the reassignments of ->f_op in ->open() instances

[linux-2.6-block.git] / include / linux / fs.h

diff --git a/include/linux/fs.h b/include/linux/fs.h
index 529d8711baba0e6ba07c57921694302332d762fd..b09e4e1d747a07d81c01840895e9a12a76ac69dd 100644 (file)
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -10,6 +10,7 @@
 #include <linux/stat.h>
 #include <linux/cache.h>
 #include <linux/list.h>
+#include <linux/list_lru.h>
 #include <linux/llist.h>
 #include <linux/radix-tree.h>
 #include <linux/rbtree.h>
@@ -1269,15 +1270,6 @@ struct super_block {
        struct list_head        s_files;
 #endif
        struct list_head        s_mounts;       /* list of mounts; _not_ for fs use */
-       /* s_dentry_lru, s_nr_dentry_unused protected by dcache.c lru locks */
-       struct list_head        s_dentry_lru;   /* unused dentry lru */
-       int                     s_nr_dentry_unused;     /* # of dentry on lru */
-
-       /* s_inode_lru_lock protects s_inode_lru and s_nr_inodes_unused */
-       spinlock_t              s_inode_lru_lock ____cacheline_aligned_in_smp;
-       struct list_head        s_inode_lru;            /* unused inode lru */
-       int                     s_nr_inodes_unused;     /* # of inodes on lru */
-
        struct block_device     *s_bdev;
        struct backing_dev_info *s_bdi;
        struct mtd_info         *s_mtd;
@@ -1331,11 +1323,14 @@ struct super_block {
 
        /* AIO completions deferred from interrupt context */
        struct workqueue_struct *s_dio_done_wq;
-};
 
-/* superblock cache pruning functions */
-extern void prune_icache_sb(struct super_block *sb, int nr_to_scan);
-extern void prune_dcache_sb(struct super_block *sb, int nr_to_scan);
+       /*
+        * Keep the lru lists last in the structure so they always sit on their
+        * own individual cachelines.
+        */
+       struct list_lru         s_dentry_lru ____cacheline_aligned_in_smp;
+       struct list_lru         s_inode_lru ____cacheline_aligned_in_smp;
+};
 
 extern struct timespec current_fs_time(struct super_block *sb);
 
@@ -1629,8 +1624,8 @@ struct super_operations {
        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);
-       int (*nr_cached_objects)(struct super_block *);
-       void (*free_cached_objects)(struct super_block *, int);
+       long (*nr_cached_objects)(struct super_block *, int);
+       long (*free_cached_objects)(struct super_block *, long, int);
 };
 
 /*
@@ -1880,6 +1875,17 @@ extern struct dentry *mount_pseudo(struct file_system_type *, char *,
        (((fops) && try_module_get((fops)->owner) ? (fops) : NULL))
 #define fops_put(fops) \
        do { if (fops) module_put((fops)->owner); } while(0)
+/*
+ * This one is to be used *ONLY* from ->open() instances.
+ * fops must be non-NULL, pinned down *and* module dependencies
+ * should be sufficient to pin the caller down as well.
+ */
+#define replace_fops(f, fops) \
+       do {    \
+               struct file *__file = (f); \
+               fops_put(__file->f_op); \
+               BUG_ON(!(__file->f_op = (fops))); \
+       } while(0)
 
 extern int register_filesystem(struct file_system_type *);
 extern int unregister_filesystem(struct file_system_type *);
@@ -2074,6 +2080,7 @@ extern struct super_block *freeze_bdev(struct block_device *);
 extern void emergency_thaw_all(void);
 extern int thaw_bdev(struct block_device *bdev, struct super_block *sb);
 extern int fsync_bdev(struct block_device *);
+extern int sb_is_blkdev_sb(struct super_block *sb);
 #else
 static inline void bd_forget(struct inode *inode) {}
 static inline int sync_blockdev(struct block_device *bdev) { return 0; }
@@ -2093,6 +2100,11 @@ static inline int thaw_bdev(struct block_device *bdev, struct super_block *sb)
 static inline void iterate_bdevs(void (*f)(struct block_device *, void *), void *arg)
 {
 }
+
+static inline int sb_is_blkdev_sb(struct super_block *sb)
+{
+       return 0;
+}
 #endif
 extern int sync_filesystem(struct super_block *);
 extern const struct file_operations def_blk_fops;
@@ -2494,7 +2506,6 @@ extern const struct file_operations generic_ro_fops;
 #define special_file(m) (S_ISCHR(m)||S_ISBLK(m)||S_ISFIFO(m)||S_ISSOCK(m))
 
 extern int vfs_readlink(struct dentry *, char __user *, int, const char *);
-extern int vfs_follow_link(struct nameidata *, const char *);
 extern int page_readlink(struct dentry *, char __user *, int);
 extern void *page_follow_link_light(struct dentry *, struct nameidata *);
 extern void page_put_link(struct dentry *, struct nameidata *, void *);
@@ -2502,6 +2513,7 @@ extern int __page_symlink(struct inode *inode, const char *symname, int len,
                int nofs);
 extern int page_symlink(struct inode *inode, const char *symname, int len);
 extern const struct inode_operations page_symlink_inode_operations;
+extern void kfree_put_link(struct dentry *, struct nameidata *, void *);
 extern int generic_readlink(struct dentry *, char __user *, int);
 extern void generic_fillattr(struct inode *, struct kstat *);
 extern int vfs_getattr(struct path *, struct kstat *);