Btrfs: finish read pages in the order they are submitted
[linux-2.6.git] / fs / locks.c
index 663c069..a8794f2 100644 (file)
@@ -151,7 +151,7 @@ static struct file_lock *locks_alloc_lock(void)
        return kmem_cache_alloc(filelock_cache, GFP_KERNEL);
 }
 
-static void locks_release_private(struct file_lock *fl)
+void locks_release_private(struct file_lock *fl)
 {
        if (fl->fl_ops) {
                if (fl->fl_ops->fl_release_private)
@@ -165,6 +165,7 @@ static void locks_release_private(struct file_lock *fl)
        }
 
 }
+EXPORT_SYMBOL_GPL(locks_release_private);
 
 /* Free a lock which is not in use. */
 static void locks_free_lock(struct file_lock *fl)
@@ -201,7 +202,7 @@ EXPORT_SYMBOL(locks_init_lock);
  * Initialises the fields of the file lock which are invariant for
  * free file_locks.
  */
-static void init_once(struct kmem_cache *cache, void *foo)
+static void init_once(void *foo)
 {
        struct file_lock *lock = (struct file_lock *) foo;
 
@@ -433,7 +434,7 @@ static int lease_mylease_callback(struct file_lock *fl, struct file_lock *try)
        return fl->fl_file == try->fl_file;
 }
 
-static struct lock_manager_operations lease_manager_ops = {
+static const struct lock_manager_operations lease_manager_ops = {
        .fl_break = lease_break_callback,
        .fl_release_private = lease_release_private_callback,
        .fl_mylease = lease_mylease_callback,
@@ -561,9 +562,6 @@ static void locks_insert_lock(struct file_lock **pos, struct file_lock *fl)
        /* insert into file's list */
        fl->fl_next = *pos;
        *pos = fl;
-
-       if (fl->fl_ops && fl->fl_ops->fl_insert)
-               fl->fl_ops->fl_insert(fl);
 }
 
 /*
@@ -586,9 +584,6 @@ static void locks_delete_lock(struct file_lock **thisfl_p)
                fl->fl_fasync = NULL;
        }
 
-       if (fl->fl_ops && fl->fl_ops->fl_remove)
-               fl->fl_ops->fl_remove(fl);
-
        if (fl->fl_nspid) {
                put_pid(fl->fl_nspid);
                fl->fl_nspid = NULL;
@@ -785,8 +780,10 @@ find_conflict:
                if (!flock_locks_conflict(request, fl))
                        continue;
                error = -EAGAIN;
-               if (request->fl_flags & FL_SLEEP)
-                       locks_insert_block(fl, request);
+               if (!(request->fl_flags & FL_SLEEP))
+                       goto out;
+               error = FILE_LOCK_DEFERRED;
+               locks_insert_block(fl, request);
                goto out;
        }
        if (request->fl_flags & FL_ACCESS)
@@ -842,7 +839,7 @@ static int __posix_lock_file(struct inode *inode, struct file_lock *request, str
                        error = -EDEADLK;
                        if (posix_locks_deadlock(request, fl))
                                goto out;
-                       error = -EAGAIN;
+                       error = FILE_LOCK_DEFERRED;
                        locks_insert_block(fl, request);
                        goto out;
                }
@@ -1041,7 +1038,7 @@ int posix_lock_file_wait(struct file *filp, struct file_lock *fl)
        might_sleep ();
        for (;;) {
                error = posix_lock_file(filp, fl, NULL);
-               if ((error != -EAGAIN) || !(fl->fl_flags & FL_SLEEP))
+               if (error != FILE_LOCK_DEFERRED)
                        break;
                error = wait_event_interruptible(fl->fl_wait, !fl->fl_next);
                if (!error)
@@ -1113,9 +1110,7 @@ int locks_mandatory_area(int read_write, struct inode *inode,
 
        for (;;) {
                error = __posix_lock_file(inode, &fl, NULL);
-               if (error != -EAGAIN)
-                       break;
-               if (!(fl.fl_flags & FL_SLEEP))
+               if (error != FILE_LOCK_DEFERRED)
                        break;
                error = wait_event_interruptible(fl.fl_wait, !fl.fl_next);
                if (!error) {
@@ -1355,7 +1350,7 @@ int generic_setlease(struct file *filp, long arg, struct file_lock **flp)
        struct inode *inode = dentry->d_inode;
        int error, rdlease_count = 0, wrlease_count = 0;
 
-       if ((current->fsuid != inode->i_uid) && !capable(CAP_LEASE))
+       if ((current_fsuid() != inode->i_uid) && !capable(CAP_LEASE))
                return -EACCES;
        if (!S_ISREG(inode->i_mode))
                return -EINVAL;
@@ -1537,7 +1532,7 @@ int flock_lock_file_wait(struct file *filp, struct file_lock *fl)
        might_sleep();
        for (;;) {
                error = flock_lock_file(filp, fl);
-               if ((error != -EAGAIN) || !(fl->fl_flags & FL_SLEEP))
+               if (error != FILE_LOCK_DEFERRED)
                        break;
                error = wait_event_interruptible(fl->fl_wait, !fl->fl_next);
                if (!error)
@@ -1570,7 +1565,7 @@ EXPORT_SYMBOL(flock_lock_file_wait);
  *     %LOCK_MAND can be combined with %LOCK_READ or %LOCK_WRITE to allow other
  *     processes read and write access respectively.
  */
-asmlinkage long sys_flock(unsigned int fd, unsigned int cmd)
+SYSCALL_DEFINE2(flock, unsigned int, fd, unsigned int, cmd)
 {
        struct file *filp;
        struct file_lock *lock;
@@ -1586,7 +1581,8 @@ asmlinkage long sys_flock(unsigned int fd, unsigned int cmd)
        cmd &= ~LOCK_NB;
        unlock = (cmd == LOCK_UN);
 
-       if (!unlock && !(cmd & LOCK_MAND) && !(filp->f_mode & 3))
+       if (!unlock && !(cmd & LOCK_MAND) &&
+           !(filp->f_mode & (FMODE_READ|FMODE_WRITE)))
                goto out_putf;
 
        error = flock_make_lock(filp, &lock, cmd);
@@ -1595,7 +1591,7 @@ asmlinkage long sys_flock(unsigned int fd, unsigned int cmd)
        if (can_sleep)
                lock->fl_flags |= FL_SLEEP;
 
-       error = security_file_lock(filp, cmd);
+       error = security_file_lock(filp, lock->fl_type);
        if (error)
                goto out_free;
 
@@ -1722,17 +1718,17 @@ out:
  * fl_grant is set. Callers expecting ->lock() to return asynchronously
  * will only use F_SETLK, not F_SETLKW; they will set FL_SLEEP if (and only if)
  * the request is for a blocking lock. When ->lock() does return asynchronously,
- * it must return -EINPROGRESS, and call ->fl_grant() when the lock
+ * it must return FILE_LOCK_DEFERRED, and call ->fl_grant() when the lock
  * request completes.
  * If the request is for non-blocking lock the file system should return
- * -EINPROGRESS then try to get the lock and call the callback routine with
- * the result. If the request timed out the callback routine will return a
+ * FILE_LOCK_DEFERRED then try to get the lock and call the callback routine
+ * with the result. If the request timed out the callback routine will return a
  * nonzero return code and the file system should release the lock. The file
  * system is also responsible to keep a corresponding posix lock when it
  * grants a lock so the VFS can find out which locks are locally held and do
  * the correct lock cleanup when required.
  * The underlying filesystem must not drop the kernel lock or call
- * ->fl_grant() before returning to the caller with a -EINPROGRESS
+ * ->fl_grant() before returning to the caller with a FILE_LOCK_DEFERRED
  * return code.
  */
 int vfs_lock_file(struct file *filp, unsigned int cmd, struct file_lock *fl, struct file_lock *conf)
@@ -1744,6 +1740,30 @@ int vfs_lock_file(struct file *filp, unsigned int cmd, struct file_lock *fl, str
 }
 EXPORT_SYMBOL_GPL(vfs_lock_file);
 
+static int do_lock_file_wait(struct file *filp, unsigned int cmd,
+                            struct file_lock *fl)
+{
+       int error;
+
+       error = security_file_lock(filp, fl->fl_type);
+       if (error)
+               return error;
+
+       for (;;) {
+               error = vfs_lock_file(filp, cmd, fl, NULL);
+               if (error != FILE_LOCK_DEFERRED)
+                       break;
+               error = wait_event_interruptible(fl->fl_wait, !fl->fl_next);
+               if (!error)
+                       continue;
+
+               locks_delete_block(fl);
+               break;
+       }
+
+       return error;
+}
+
 /* Apply the lock described by l to an open file descriptor.
  * This implements both the F_SETLK and F_SETLKW commands of fcntl().
  */
@@ -1753,6 +1773,7 @@ int fcntl_setlk(unsigned int fd, struct file *filp, unsigned int cmd,
        struct file_lock *file_lock = locks_alloc_lock();
        struct flock flock;
        struct inode *inode;
+       struct file *f;
        int error;
 
        if (file_lock == NULL)
@@ -1800,32 +1821,21 @@ again:
                goto out;
        }
 
-       error = security_file_lock(filp, file_lock->fl_type);
-       if (error)
-               goto out;
-
-       if (filp->f_op && filp->f_op->lock != NULL)
-               error = filp->f_op->lock(filp, cmd, file_lock);
-       else {
-               for (;;) {
-                       error = posix_lock_file(filp, file_lock, NULL);
-                       if (error != -EAGAIN || cmd == F_SETLK)
-                               break;
-                       error = wait_event_interruptible(file_lock->fl_wait,
-                                       !file_lock->fl_next);
-                       if (!error)
-                               continue;
-
-                       locks_delete_block(file_lock);
-                       break;
-               }
-       }
+       error = do_lock_file_wait(filp, cmd, file_lock);
 
        /*
         * Attempt to detect a close/fcntl race and recover by
         * releasing the lock that was just acquired.
         */
-       if (!error && fcheck(fd) != filp && flock.l_type != F_UNLCK) {
+       /*
+        * we need that spin_lock here - it prevents reordering between
+        * update of inode->i_flock and check for it done in close().
+        * rcu_read_lock() wouldn't do.
+        */
+       spin_lock(&current->files->file_lock);
+       f = fcheck(fd);
+       spin_unlock(&current->files->file_lock);
+       if (!error && f != filp && flock.l_type != F_UNLCK) {
                flock.l_type = F_UNLCK;
                goto again;
        }
@@ -1881,6 +1891,7 @@ int fcntl_setlk64(unsigned int fd, struct file *filp, unsigned int cmd,
        struct file_lock *file_lock = locks_alloc_lock();
        struct flock64 flock;
        struct inode *inode;
+       struct file *f;
        int error;
 
        if (file_lock == NULL)
@@ -1928,32 +1939,16 @@ again:
                goto out;
        }
 
-       error = security_file_lock(filp, file_lock->fl_type);
-       if (error)
-               goto out;
-
-       if (filp->f_op && filp->f_op->lock != NULL)
-               error = filp->f_op->lock(filp, cmd, file_lock);
-       else {
-               for (;;) {
-                       error = posix_lock_file(filp, file_lock, NULL);
-                       if (error != -EAGAIN || cmd == F_SETLK64)
-                               break;
-                       error = wait_event_interruptible(file_lock->fl_wait,
-                                       !file_lock->fl_next);
-                       if (!error)
-                               continue;
-
-                       locks_delete_block(file_lock);
-                       break;
-               }
-       }
+       error = do_lock_file_wait(filp, cmd, file_lock);
 
        /*
         * Attempt to detect a close/fcntl race and recover by
         * releasing the lock that was just acquired.
         */
-       if (!error && fcheck(fd) != filp && flock.l_type != F_UNLCK) {
+       spin_lock(&current->files->file_lock);
+       f = fcheck(fd);
+       spin_unlock(&current->files->file_lock);
+       if (!error && f != filp && flock.l_type != F_UNLCK) {
                flock.l_type = F_UNLCK;
                goto again;
        }
@@ -2085,6 +2080,7 @@ int vfs_cancel_lock(struct file *filp, struct file_lock *fl)
 EXPORT_SYMBOL_GPL(vfs_cancel_lock);
 
 #ifdef CONFIG_PROC_FS
+#include <linux/proc_fs.h>
 #include <linux/seq_file.h>
 
 static void lock_get_status(struct seq_file *f, struct file_lock *fl,
@@ -2190,12 +2186,31 @@ static void locks_stop(struct seq_file *f, void *v)
        unlock_kernel();
 }
 
-struct seq_operations locks_seq_operations = {
+static const struct seq_operations locks_seq_operations = {
        .start  = locks_start,
        .next   = locks_next,
        .stop   = locks_stop,
        .show   = locks_show,
 };
+
+static int locks_open(struct inode *inode, struct file *filp)
+{
+       return seq_open(filp, &locks_seq_operations);
+}
+
+static const struct file_operations proc_locks_operations = {
+       .open           = locks_open,
+       .read           = seq_read,
+       .llseek         = seq_lseek,
+       .release        = seq_release,
+};
+
+static int __init proc_locks_init(void)
+{
+       proc_create("locks", 0, NULL, &proc_locks_operations);
+       return 0;
+}
+module_init(proc_locks_init);
 #endif
 
 /**