reiserfs: constify xattr_handler
[safe/jmp/linux-2.6] / fs / sync.c
index b75ca68..d536920 100644 (file)
--- a/fs/sync.c
+++ b/fs/sync.c
@@ -5,6 +5,7 @@
 #include <linux/kernel.h>
 #include <linux/file.h>
 #include <linux/fs.h>
+#include <linux/slab.h>
 #include <linux/module.h>
 #include <linux/sched.h>
 #include <linux/writeback.h>
@@ -13,6 +14,7 @@
 #include <linux/pagemap.h>
 #include <linux/quotaops.h>
 #include <linux/buffer_head.h>
+#include <linux/backing-dev.h>
 #include "internal.h"
 
 #define VALID_FLAGS (SYNC_FILE_RANGE_WAIT_BEFORE|SYNC_FILE_RANGE_WRITE| \
@@ -31,17 +33,17 @@ static int __sync_filesystem(struct super_block *sb, int wait)
         * This should be safe, as we require bdi backing to actually
         * write out data in the first place
         */
-       if (!sb->s_bdi)
+       if (!sb->s_bdi || sb->s_bdi == &noop_backing_dev_info)
                return 0;
 
-       /* Avoid doing twice syncing and cache pruning for quota sync */
-       if (!wait) {
-               writeout_quota_sb(sb, -1);
-               writeback_inodes_sb(sb);
-       } else {
-               sync_quota_sb(sb, -1);
+       if (sb->s_qcop && sb->s_qcop->quota_sync)
+               sb->s_qcop->quota_sync(sb, -1, wait);
+
+       if (wait)
                sync_inodes_sb(sb);
-       }
+       else
+               writeback_inodes_sb(sb);
+
        if (sb->s_op->sync_fs)
                sb->s_op->sync_fs(sb, wait);
        return __sync_blockdev(sb->s_bdev, wait);
@@ -75,50 +77,18 @@ int sync_filesystem(struct super_block *sb)
 }
 EXPORT_SYMBOL_GPL(sync_filesystem);
 
+static void sync_one_sb(struct super_block *sb, void *arg)
+{
+       if (!(sb->s_flags & MS_RDONLY) && sb->s_bdi)
+               __sync_filesystem(sb, *(int *)arg);
+}
 /*
  * Sync all the data for all the filesystems (called by sys_sync() and
  * emergency sync)
- *
- * This operation is careful to avoid the livelock which could easily happen
- * if two or more filesystems are being continuously dirtied.  s_need_sync
- * is used only here.  We set it against all filesystems and then clear it as
- * we sync them.  So redirtied filesystems are skipped.
- *
- * But if process A is currently running sync_filesystems and then process B
- * calls sync_filesystems as well, process B will set all the s_need_sync
- * flags again, which will cause process A to resync everything.  Fix that with
- * a local mutex.
  */
 static void sync_filesystems(int wait)
 {
-       struct super_block *sb;
-       static DEFINE_MUTEX(mutex);
-
-       mutex_lock(&mutex);             /* Could be down_interruptible */
-       spin_lock(&sb_lock);
-       list_for_each_entry(sb, &super_blocks, s_list)
-               sb->s_need_sync = 1;
-
-restart:
-       list_for_each_entry(sb, &super_blocks, s_list) {
-               if (!sb->s_need_sync)
-                       continue;
-               sb->s_need_sync = 0;
-               sb->s_count++;
-               spin_unlock(&sb_lock);
-
-               down_read(&sb->s_umount);
-               if (!(sb->s_flags & MS_RDONLY) && sb->s_root && sb->s_bdi)
-                       __sync_filesystem(sb, wait);
-               up_read(&sb->s_umount);
-
-               /* restart only when sb is no longer on the list */
-               spin_lock(&sb_lock);
-               if (__put_super_and_need_restart(sb))
-                       goto restart;
-       }
-       spin_unlock(&sb_lock);
-       mutex_unlock(&mutex);
+       iterate_supers(sync_one_sb, &wait);
 }
 
 /*
@@ -355,6 +325,7 @@ SYSCALL_DEFINE(sync_file_range)(int fd, loff_t offset, loff_t nbytes,
 {
        int ret;
        struct file *file;
+       struct address_space *mapping;
        loff_t endbyte;                 /* inclusive */
        int fput_needed;
        umode_t i_mode;
@@ -405,7 +376,28 @@ SYSCALL_DEFINE(sync_file_range)(int fd, loff_t offset, loff_t nbytes,
                        !S_ISLNK(i_mode))
                goto out_put;
 
-       ret = do_sync_mapping_range(file->f_mapping, offset, endbyte, flags);
+       mapping = file->f_mapping;
+       if (!mapping) {
+               ret = -EINVAL;
+               goto out_put;
+       }
+
+       ret = 0;
+       if (flags & SYNC_FILE_RANGE_WAIT_BEFORE) {
+               ret = filemap_fdatawait_range(mapping, offset, endbyte);
+               if (ret < 0)
+                       goto out_put;
+       }
+
+       if (flags & SYNC_FILE_RANGE_WRITE) {
+               ret = filemap_fdatawrite_range(mapping, offset, endbyte);
+               if (ret < 0)
+                       goto out_put;
+       }
+
+       if (flags & SYNC_FILE_RANGE_WAIT_AFTER)
+               ret = filemap_fdatawait_range(mapping, offset, endbyte);
+
 out_put:
        fput_light(file, fput_needed);
 out:
@@ -437,42 +429,3 @@ asmlinkage long SyS_sync_file_range2(long fd, long flags,
 }
 SYSCALL_ALIAS(sys_sync_file_range2, SyS_sync_file_range2);
 #endif
-
-/*
- * `endbyte' is inclusive
- */
-int do_sync_mapping_range(struct address_space *mapping, loff_t offset,
-                         loff_t endbyte, unsigned int flags)
-{
-       int ret;
-
-       if (!mapping) {
-               ret = -EINVAL;
-               goto out;
-       }
-
-       ret = 0;
-       if (flags & SYNC_FILE_RANGE_WAIT_BEFORE) {
-               ret = wait_on_page_writeback_range(mapping,
-                                       offset >> PAGE_CACHE_SHIFT,
-                                       endbyte >> PAGE_CACHE_SHIFT);
-               if (ret < 0)
-                       goto out;
-       }
-
-       if (flags & SYNC_FILE_RANGE_WRITE) {
-               ret = __filemap_fdatawrite_range(mapping, offset, endbyte,
-                                               WB_SYNC_ALL);
-               if (ret < 0)
-                       goto out;
-       }
-
-       if (flags & SYNC_FILE_RANGE_WAIT_AFTER) {
-               ret = wait_on_page_writeback_range(mapping,
-                                       offset >> PAGE_CACHE_SHIFT,
-                                       endbyte >> PAGE_CACHE_SHIFT);
-       }
-out:
-       return ret;
-}
-EXPORT_SYMBOL_GPL(do_sync_mapping_range);