#include <linux/kernel.h>
#include <linux/file.h>
#include <linux/fs.h>
-#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/export.h>
+#include <linux/namei.h>
#include <linux/sched.h>
#include <linux/writeback.h>
#include <linux/syscalls.h>
#include <linux/linkage.h>
#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| \
SYNC_FILE_RANGE_WAIT_AFTER)
/*
- * sync everything. Start out by waking pdflush, because that writes back
- * all queues in parallel.
+ * Do the filesystem syncing work. For simple filesystems
+ * writeback_inodes_sb(sb) just dirties buffers with inodes so we have to
+ * submit IO for these buffers via __sync_blockdev(). This also speeds up the
+ * wait == 1 case since in that case write_inode() functions do
+ * sync_dirty_buffer() and thus effectively write one block at a time.
*/
-static void do_sync(unsigned long wait)
+static int __sync_filesystem(struct super_block *sb, int wait)
{
- wakeup_pdflush(0);
- sync_inodes(0); /* All mappings, inodes and their blockdevs */
- DQUOT_SYNC(NULL);
- sync_supers(); /* Write the superblocks */
- sync_filesystems(0); /* Start syncing the filesystems */
- sync_filesystems(wait); /* Waitingly sync the filesystems */
- sync_inodes(wait); /* Mappings, inodes and blockdevs, again. */
- if (!wait)
- printk("Emergency Sync complete\n");
- if (unlikely(laptop_mode))
- laptop_sync_completion();
+ if (wait)
+ sync_inodes_sb(sb);
+ else
+ writeback_inodes_sb(sb, WB_REASON_SYNC);
+
+ if (sb->s_op->sync_fs)
+ sb->s_op->sync_fs(sb, wait);
+ return __sync_blockdev(sb->s_bdev, wait);
}
-asmlinkage long sys_sync(void)
+/*
+ * Write out and wait upon all dirty data associated with this
+ * superblock. Filesystem data as well as the underlying block
+ * device. Takes the superblock lock.
+ */
+int sync_filesystem(struct super_block *sb)
{
- do_sync(1);
- return 0;
+ int ret;
+
+ /*
+ * We need to be protected against the filesystem going from
+ * r/o to r/w or vice versa.
+ */
+ WARN_ON(!rwsem_is_locked(&sb->s_umount));
+
+ /*
+ * No point in syncing out anything if the filesystem is read-only.
+ */
+ if (sb->s_flags & MS_RDONLY)
+ return 0;
+
+ ret = __sync_filesystem(sb, 0);
+ if (ret < 0)
+ return ret;
+ return __sync_filesystem(sb, 1);
}
+EXPORT_SYMBOL_GPL(sync_filesystem);
-void emergency_sync(void)
+static void sync_inodes_one_sb(struct super_block *sb, void *arg)
+{
+ if (!(sb->s_flags & MS_RDONLY))
+ sync_inodes_sb(sb);
+}
+
+static void sync_fs_one_sb(struct super_block *sb, void *arg)
+{
+ 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)
{
- pdflush_operation(do_sync, 0);
+ 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);
}
/*
- * Generic function to fsync a file.
- *
- * filp may be NULL if called via the msync of a vma.
+ * 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().
*/
-int file_fsync(struct file *filp, struct dentry *dentry, int datasync)
+SYSCALL_DEFINE0(sync)
{
- struct inode * inode = dentry->d_inode;
- struct super_block * sb;
- int ret, err;
-
- /* sync the inode to buffers */
- ret = write_inode_now(inode, 0);
-
- /* sync the superblock to buffers */
- sb = inode->i_sb;
- lock_super(sb);
- if (sb->s_op->write_super)
- sb->s_op->write_super(sb);
- unlock_super(sb);
-
- /* .. finally sync the buffers to disk */
- err = sync_blockdev(sb->s_bdev);
- if (!ret)
- ret = err;
- return ret;
+ int nowait = 0, wait = 1;
+
+ wakeup_flusher_threads(0, WB_REASON_SYNC);
+ 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;
}
-long do_fsync(struct file *file, int datasync)
+static void do_sync_work(struct work_struct *work)
{
- int ret;
- int err;
- struct address_space *mapping = file->f_mapping;
+ int nowait = 0;
- if (!file->f_op || !file->f_op->fsync) {
- /* Why? We can still call filemap_fdatawrite */
- ret = -EINVAL;
- goto out;
+ /*
+ * Sync twice to reduce the possibility we skipped some inodes / pages
+ * because they were temporarily locked
+ */
+ 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);
+}
+
+void emergency_sync(void)
+{
+ struct work_struct *work;
+
+ work = kmalloc(sizeof(*work), GFP_ATOMIC);
+ if (work) {
+ INIT_WORK(work, do_sync_work);
+ schedule_work(work);
}
+}
+
+/*
+ * sync a single super
+ */
+SYSCALL_DEFINE1(syncfs, int, fd)
+{
+ struct fd f = fdget(fd);
+ struct super_block *sb;
+ int ret;
- ret = filemap_fdatawrite(mapping);
+ if (!f.file)
+ return -EBADF;
+ sb = f.file->f_dentry->d_sb;
- /*
- * We need to protect against concurrent writers, which could cause
- * livelocks in fsync_buffers_list().
- */
- mutex_lock(&mapping->host->i_mutex);
- err = file->f_op->fsync(file, file->f_path.dentry, datasync);
- if (!ret)
- ret = err;
- mutex_unlock(&mapping->host->i_mutex);
- err = filemap_fdatawait(mapping);
- if (!ret)
- ret = err;
-out:
+ down_read(&sb->s_umount);
+ ret = sync_filesystem(sb);
+ up_read(&sb->s_umount);
+
+ fdput(f);
return ret;
}
-static long __do_fsync(unsigned int fd, int datasync)
+/**
+ * vfs_fsync_range - helper to sync a range of data & metadata to disk
+ * @file: file to sync
+ * @start: offset in bytes of the beginning of data range to sync
+ * @end: offset in bytes of the end of data range (inclusive)
+ * @datasync: perform only datasync
+ *
+ * Write back data in range @start..@end and metadata for @file to disk. If
+ * @datasync is set only metadata needed to access modified file data is
+ * written.
+ */
+int vfs_fsync_range(struct file *file, loff_t start, loff_t end, int datasync)
+{
+ if (!file->f_op || !file->f_op->fsync)
+ return -EINVAL;
+ return file->f_op->fsync(file, start, end, datasync);
+}
+EXPORT_SYMBOL(vfs_fsync_range);
+
+/**
+ * vfs_fsync - perform a fsync or fdatasync on a file
+ * @file: file to sync
+ * @datasync: only perform a fdatasync operation
+ *
+ * Write back data and metadata for @file to disk. If @datasync is
+ * set only metadata needed to access modified file data is written.
+ */
+int vfs_fsync(struct file *file, int datasync)
{
- struct file *file;
+ return vfs_fsync_range(file, 0, LLONG_MAX, datasync);
+}
+EXPORT_SYMBOL(vfs_fsync);
+
+static int do_fsync(unsigned int fd, int datasync)
+{
+ struct fd f = fdget(fd);
int ret = -EBADF;
- file = fget(fd);
- if (file) {
- ret = do_fsync(file, datasync);
- fput(file);
+ if (f.file) {
+ ret = vfs_fsync(f.file, datasync);
+ fdput(f);
}
return ret;
}
-asmlinkage long sys_fsync(unsigned int fd)
+SYSCALL_DEFINE1(fsync, unsigned int, fd)
{
- return __do_fsync(fd, 0);
+ return do_fsync(fd, 0);
}
-asmlinkage long sys_fdatasync(unsigned int fd)
+SYSCALL_DEFINE1(fdatasync, unsigned int, fd)
{
- return __do_fsync(fd, 1);
+ return do_fsync(fd, 1);
}
+/**
+ * generic_write_sync - perform syncing after a write if file / inode is sync
+ * @file: file to which the write happened
+ * @pos: offset where the write started
+ * @count: length of the write
+ *
+ * This is just a simple wrapper about our general syncing function.
+ */
+int generic_write_sync(struct file *file, loff_t pos, loff_t count)
+{
+ if (!(file->f_flags & O_DSYNC) && !IS_SYNC(file->f_mapping->host))
+ return 0;
+ return vfs_fsync_range(file, pos, pos + count - 1,
+ (file->f_flags & __O_SYNC) ? 0 : 1);
+}
+EXPORT_SYMBOL(generic_write_sync);
+
/*
* sys_sync_file_range() permits finely controlled syncing over a segment of
* a file in the range offset .. (offset+nbytes-1) inclusive. If nbytes is
* before performing the write.
*
* SYNC_FILE_RANGE_WRITE: initiate writeout of all those dirty pages in the
- * range which are not presently under writeback.
+ * range which are not presently under writeback. Note that this may block for
+ * significant periods due to exhaustion of disk request structures.
*
* SYNC_FILE_RANGE_WAIT_AFTER: wait upon writeout of all pages in the range
* after performing the write.
* already-instantiated disk blocks, there are no guarantees here that the data
* will be available after a crash.
*/
-asmlinkage long sys_sync_file_range(int fd, loff_t offset, loff_t nbytes,
- unsigned int flags)
+SYSCALL_DEFINE4(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;
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 = file_inode(f.file)->i_mode;
ret = -ESPIPE;
if (!S_ISREG(i_mode) && !S_ISBLK(i_mode) && !S_ISDIR(i_mode) &&
!S_ISLNK(i_mode))
goto out_put;
- ret = do_sync_file_range(file, offset, endbyte, flags);
-out_put:
- fput_light(file, fput_needed);
-out:
- return ret;
-}
-
-/*
- * `endbyte' is inclusive
- */
-int do_sync_mapping_range(struct address_space *mapping, loff_t offset,
- loff_t endbyte, unsigned int flags)
-{
- int ret;
-
+ mapping = f.file->f_mapping;
if (!mapping) {
ret = -EINVAL;
- goto out;
+ goto out_put;
}
ret = 0;
if (flags & SYNC_FILE_RANGE_WAIT_BEFORE) {
- ret = wait_on_page_writeback_range(mapping,
- offset >> PAGE_CACHE_SHIFT,
- endbyte >> PAGE_CACHE_SHIFT);
+ ret = filemap_fdatawait_range(mapping, offset, endbyte);
if (ret < 0)
- goto out;
+ goto out_put;
}
if (flags & SYNC_FILE_RANGE_WRITE) {
- ret = __filemap_fdatawrite_range(mapping, offset, endbyte,
- WB_SYNC_NONE);
+ ret = filemap_fdatawrite_range(mapping, offset, endbyte);
if (ret < 0)
- goto out;
+ goto out_put;
}
- if (flags & SYNC_FILE_RANGE_WAIT_AFTER) {
- ret = wait_on_page_writeback_range(mapping,
- offset >> PAGE_CACHE_SHIFT,
- endbyte >> PAGE_CACHE_SHIFT);
- }
+ if (flags & SYNC_FILE_RANGE_WAIT_AFTER)
+ ret = filemap_fdatawait_range(mapping, offset, endbyte);
+
+out_put:
+ fdput(f);
out:
return ret;
}
-EXPORT_SYMBOL_GPL(do_sync_mapping_range);
+
+/* It would be nice if people remember that not all the world's an i386
+ when they introduce new system calls */
+SYSCALL_DEFINE4(sync_file_range2, int, fd, unsigned int, flags,
+ loff_t, offset, loff_t, nbytes)
+{
+ return sys_sync_file_range(fd, offset, nbytes, flags);
+}
Code Review / linux-3.10.git / blobdiff