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-rw-r--r--fs/sync.c96
1 files changed, 53 insertions, 43 deletions
diff --git a/fs/sync.c b/fs/sync.c
index 11e3d1c4490..14eefeb4463 100644
--- a/fs/sync.c
+++ b/fs/sync.c
@@ -29,16 +29,6 @@
*/
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 == &noop_backing_dev_info)
- return 0;
-
- if (sb->s_qcop && sb->s_qcop->quota_sync)
- sb->s_qcop->quota_sync(sb, -1, wait);
-
if (wait)
sync_inodes_sb(sb);
else
@@ -77,29 +67,48 @@ int sync_filesystem(struct super_block *sb)
}
EXPORT_SYMBOL_GPL(sync_filesystem);
-static void sync_one_sb(struct super_block *sb, void *arg)
+static void sync_inodes_one_sb(struct super_block *sb, void *arg)
{
if (!(sb->s_flags & MS_RDONLY))
- __sync_filesystem(sb, *(int *)arg);
+ sync_inodes_sb(sb);
}
-/*
- * Sync all the data for all the filesystems (called by sys_sync() and
- * emergency sync)
- */
-static void sync_filesystems(int wait)
+
+static void sync_fs_one_sb(struct super_block *sb, void *arg)
{
- iterate_supers(sync_one_sb, &wait);
+ if (!(sb->s_flags & MS_RDONLY) && sb->s_op->sync_fs)
+ sb->s_op->sync_fs(sb, *(int *)arg);
+}
+
+static void fdatawrite_one_bdev(struct block_device *bdev, void *arg)
+{
+ filemap_fdatawrite(bdev->bd_inode->i_mapping);
+}
+
+static void fdatawait_one_bdev(struct block_device *bdev, void *arg)
+{
+ filemap_fdatawait(bdev->bd_inode->i_mapping);
}
/*
- * sync everything. Start out by waking pdflush, because that writes back
- * all queues in parallel.
+ * Sync everything. We start by waking flusher threads so that most of
+ * writeback runs on all devices in parallel. Then we sync all inodes reliably
+ * which effectively also waits for all flusher threads to finish doing
+ * writeback. At this point all data is on disk so metadata should be stable
+ * and we tell filesystems to sync their metadata via ->sync_fs() calls.
+ * Finally, we writeout all block devices because some filesystems (e.g. ext2)
+ * just write metadata (such as inodes or bitmaps) to block device page cache
+ * and do not sync it on their own in ->sync_fs().
*/
SYSCALL_DEFINE0(sync)
{
+ int nowait = 0, wait = 1;
+
wakeup_flusher_threads(0, WB_REASON_SYNC);
- sync_filesystems(0);
- sync_filesystems(1);
+ iterate_supers(sync_inodes_one_sb, NULL);
+ iterate_supers(sync_fs_one_sb, &nowait);
+ iterate_supers(sync_fs_one_sb, &wait);
+ iterate_bdevs(fdatawrite_one_bdev, NULL);
+ iterate_bdevs(fdatawait_one_bdev, NULL);
if (unlikely(laptop_mode))
laptop_sync_completion();
return 0;
@@ -107,12 +116,18 @@ SYSCALL_DEFINE0(sync)
static void do_sync_work(struct work_struct *work)
{
+ int nowait = 0;
+
/*
* Sync twice to reduce the possibility we skipped some inodes / pages
* because they were temporarily locked
*/
- sync_filesystems(0);
- sync_filesystems(0);
+ iterate_supers(sync_inodes_one_sb, &nowait);
+ iterate_supers(sync_fs_one_sb, &nowait);
+ iterate_bdevs(fdatawrite_one_bdev, NULL);
+ iterate_supers(sync_inodes_one_sb, &nowait);
+ iterate_supers(sync_fs_one_sb, &nowait);
+ iterate_bdevs(fdatawrite_one_bdev, NULL);
printk("Emergency Sync complete\n");
kfree(work);
}
@@ -133,21 +148,19 @@ void emergency_sync(void)
*/
SYSCALL_DEFINE1(syncfs, int, fd)
{
- struct file *file;
+ struct fd f = fdget(fd);
struct super_block *sb;
int ret;
- int fput_needed;
- file = fget_light(fd, &fput_needed);
- if (!file)
+ if (!f.file)
return -EBADF;
- sb = file->f_dentry->d_sb;
+ sb = f.file->f_dentry->d_sb;
down_read(&sb->s_umount);
ret = sync_filesystem(sb);
up_read(&sb->s_umount);
- fput_light(file, fput_needed);
+ fdput(f);
return ret;
}
@@ -186,14 +199,12 @@ EXPORT_SYMBOL(vfs_fsync);
static int do_fsync(unsigned int fd, int datasync)
{
- struct file *file;
+ struct fd f = fdget(fd);
int ret = -EBADF;
- int fput_needed;
- file = fget_light(fd, &fput_needed);
- if (file) {
- ret = vfs_fsync(file, datasync);
- fput_light(file, fput_needed);
+ if (f.file) {
+ ret = vfs_fsync(f.file, datasync);
+ fdput(f);
}
return ret;
}
@@ -276,10 +287,9 @@ SYSCALL_DEFINE(sync_file_range)(int fd, loff_t offset, loff_t nbytes,
unsigned int flags)
{
int ret;
- struct file *file;
+ struct fd f;
struct address_space *mapping;
loff_t endbyte; /* inclusive */
- int fput_needed;
umode_t i_mode;
ret = -EINVAL;
@@ -318,17 +328,17 @@ SYSCALL_DEFINE(sync_file_range)(int fd, loff_t offset, loff_t nbytes,
endbyte--; /* inclusive */
ret = -EBADF;
- file = fget_light(fd, &fput_needed);
- if (!file)
+ f = fdget(fd);
+ if (!f.file)
goto out;
- i_mode = file->f_path.dentry->d_inode->i_mode;
+ i_mode = f.file->f_path.dentry->d_inode->i_mode;
ret = -ESPIPE;
if (!S_ISREG(i_mode) && !S_ISBLK(i_mode) && !S_ISDIR(i_mode) &&
!S_ISLNK(i_mode))
goto out_put;
- mapping = file->f_mapping;
+ mapping = f.file->f_mapping;
if (!mapping) {
ret = -EINVAL;
goto out_put;
@@ -351,7 +361,7 @@ SYSCALL_DEFINE(sync_file_range)(int fd, loff_t offset, loff_t nbytes,
ret = filemap_fdatawait_range(mapping, offset, endbyte);
out_put:
- fput_light(file, fput_needed);
+ fdput(f);
out:
return ret;
}