vserver 1.9.5.x5

[linux-2.6.git] / Documentation / filesystems / Locking

diff --git a/Documentation/filesystems/Locking b/Documentation/filesystems/Locking
index 1c465ed..2c9ce27 100644 (file)
--- a/Documentation/filesystems/Locking
+++ b/Documentation/filesystems/Locking
@@ -90,7 +90,7 @@ prototypes:
        void (*destroy_inode)(struct inode *);
        void (*read_inode) (struct inode *);
        void (*dirty_inode) (struct inode *);
        void (*destroy_inode)(struct inode *);
        void (*read_inode) (struct inode *);
        void (*dirty_inode) (struct inode *);

-       void (*write_inode) (struct inode *, int);
+       int (*write_inode) (struct inode *, int);

        void (*put_inode) (struct inode *);
        void (*drop_inode) (struct inode *);
        void (*delete_inode) (struct inode *);
        void (*put_inode) (struct inode *);
        void (*drop_inode) (struct inode *);
        void (*delete_inode) (struct inode *);


@@ -276,21 +276,40 @@ foo_get_block(). It's an overkill, since block bitmaps can be protected by
 internal fs locking and real critical areas are much smaller than the areas
 filesystems protect now.
 
 internal fs locking and real critical areas are much smaller than the areas
 filesystems protect now.
 

---------------------------- file_lock ------------------------------------
+----------------------- file_lock_operations ------------------------------

 prototypes:
 prototypes:

-       void (*fl_notify)(struct file_lock *);  /* unblock callback */

        void (*fl_insert)(struct file_lock *);  /* lock insertion callback */
        void (*fl_remove)(struct file_lock *);  /* lock removal callback */
        void (*fl_insert)(struct file_lock *);  /* lock insertion callback */
        void (*fl_remove)(struct file_lock *);  /* lock removal callback */

+       void (*fl_copy_lock)(struct file_lock *, struct file_lock *);
+       void (*fl_release_private)(struct file_lock *);
+

 
 locking rules:
 
 locking rules:

-               BKL     may block
-fl_notify:     yes     no
-fl_insert:     yes     no
-fl_remove:     yes     no
-       Currently only NLM provides instances of this class. None of the
+                       BKL     may block
+fl_insert:             yes     no
+fl_remove:             yes     no
+fl_copy_lock:          yes     no
+fl_release_private:    yes     yes
+
+----------------------- lock_manager_operations ---------------------------
+prototypes:
+       int (*fl_compare_owner)(struct file_lock *, struct file_lock *);
+       void (*fl_notify)(struct file_lock *);  /* unblock callback */
+       void (*fl_copy_lock)(struct file_lock *, struct file_lock *);
+       void (*fl_release_private)(struct file_lock *);
+       void (*fl_break)(struct file_lock *); /* break_lease callback */
+
+locking rules:
+                       BKL     may block
+fl_compare_owner:      yes     no
+fl_notify:             yes     no
+fl_copy_lock:          yes     no
+fl_release_private:    yes     yes
+fl_break:              yes     no
+
+       Currently only NFSD and NLM provide instances of this class. None of the

 them block. If you have out-of-tree instances - please, show up. Locking
 in that area will change.
 them block. If you have out-of-tree instances - please, show up. Locking
 in that area will change.

-

 --------------------------- buffer_head -----------------------------------
 prototypes:
        void (*b_end_io)(struct buffer_head *bh, int uptodate);
 --------------------------- buffer_head -----------------------------------
 prototypes:
        void (*b_end_io)(struct buffer_head *bh, int uptodate);


@@ -298,8 +317,8 @@ prototypes:
 locking rules:
        called from interrupts. In other words, extreme care is needed here.
 bh is locked, but that's all warranties we have here. Currently only RAID1,
 locking rules:
        called from interrupts. In other words, extreme care is needed here.
 bh is locked, but that's all warranties we have here. Currently only RAID1,

-highmem and fs/buffer.c are providing these. Block devices call this method
-upon the IO completion.
+highmem, fs/buffer.c, and fs/ntfs/aops.c are providing these. Block devices
+call this method upon the IO completion.

 
 --------------------------- block_device_operations -----------------------
 prototypes:
 
 --------------------------- block_device_operations -----------------------
 prototypes:


@@ -331,6 +350,8 @@ prototypes:
        unsigned int (*poll) (struct file *, struct poll_table_struct *);
        int (*ioctl) (struct inode *, struct file *, unsigned int,
                        unsigned long);
        unsigned int (*poll) (struct file *, struct poll_table_struct *);
        int (*ioctl) (struct inode *, struct file *, unsigned int,
                        unsigned long);

+       long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
+       long (*compat_ioctl) (struct file *, unsigned int, unsigned long);

        int (*mmap) (struct file *, struct vm_area_struct *);
        int (*open) (struct inode *, struct file *);
        int (*flush) (struct file *);
        int (*mmap) (struct file *, struct vm_area_struct *);
        int (*open) (struct inode *, struct file *);
        int (*flush) (struct file *);


@@ -364,6 +385,8 @@ aio_write:          no
 readdir:               no
 poll:                  no
 ioctl:                 yes     (see below)
 readdir:               no
 poll:                  no
 ioctl:                 yes     (see below)

+unlocked_ioctl:                no      (see below)
+compat_ioctl:          no

 mmap:                  no
 open:                  maybe   (see below)
 flush:                 no
 mmap:                  no
 open:                  maybe   (see below)
 flush:                 no


@@ -409,6 +432,9 @@ move ->readdir() to inode_operations and use a separate method for directory
 anything that resembles union-mount we won't have a struct file for all
 components. And there are other reasons why the current interface is a mess...
 
 anything that resembles union-mount we won't have a struct file for all
 components. And there are other reasons why the current interface is a mess...
 

+->ioctl() on regular files is superceded by the ->unlocked_ioctl() that
+doesn't take the BKL.
+

 ->read on directories probably must go away - we should just enforce -EISDIR
 in sys_read() and friends.
 
 ->read on directories probably must go away - we should just enforce -EISDIR
 in sys_read() and friends.