#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>
#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)
+/*
+ * 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 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 || 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
+ writeback_inodes_sb(sb);
+
+ if (sb->s_op->sync_fs)
+ sb->s_op->sync_fs(sb, wait);
+ return __sync_blockdev(sb->s_bdev, wait);
+}
+
+/*
+ * 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)
+{
+ 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);
+
+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)
+ */
+static void sync_filesystems(int wait)
+{
+ iterate_supers(sync_one_sb, &wait);
+}
+
/*
* sync everything. Start out by waking pdflush, because that writes back
* all queues in parallel.
*/
-static void do_sync(unsigned long wait)
+SYSCALL_DEFINE0(sync)
{
- 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");
+ wakeup_flusher_threads(0);
+ sync_filesystems(0);
+ sync_filesystems(1);
if (unlikely(laptop_mode))
laptop_sync_completion();
+ return 0;
}
-asmlinkage long sys_sync(void)
+static void do_sync_work(struct work_struct *work)
{
- do_sync(1);
- return 0;
+ /*
+ * Sync twice to reduce the possibility we skipped some inodes / pages
+ * because they were temporarily locked
+ */
+ sync_filesystems(0);
+ sync_filesystems(0);
+ printk("Emergency Sync complete\n");
+ kfree(work);
}
void emergency_sync(void)
{
- pdflush_operation(do_sync, 0);
+ struct work_struct *work;
+
+ work = kmalloc(sizeof(*work), GFP_ATOMIC);
+ if (work) {
+ INIT_WORK(work, do_sync_work);
+ schedule_work(work);
+ }
}
/*
* Generic function to fsync a file.
- *
- * filp may be NULL if called via the msync of a vma.
*/
-int file_fsync(struct file *filp, struct dentry *dentry, int datasync)
+int file_fsync(struct file *filp, int datasync)
{
- struct inode * inode = dentry->d_inode;
+ struct inode *inode = filp->f_mapping->host;
struct super_block * sb;
int ret, err;
/* sync the superblock to buffers */
sb = inode->i_sb;
- lock_super(sb);
- if (sb->s_op->write_super)
+ if (sb->s_dirt && 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);
ret = err;
return ret;
}
+EXPORT_SYMBOL(file_fsync);
-long do_fsync(struct file *file, 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)
{
- int ret;
- int err;
struct address_space *mapping = file->f_mapping;
+ int err, ret;
if (!file->f_op || !file->f_op->fsync) {
- /* Why? We can still call filemap_fdatawrite */
ret = -EINVAL;
goto out;
}
- ret = filemap_fdatawrite(mapping);
+ ret = filemap_write_and_wait_range(mapping, start, end);
/*
* 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);
+ err = file->f_op->fsync(file, datasync);
if (!ret)
ret = err;
mutex_unlock(&mapping->host->i_mutex);
- err = filemap_fdatawait(mapping);
- if (!ret)
- ret = err;
+
out:
return ret;
}
+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)
+{
+ return vfs_fsync_range(file, 0, LLONG_MAX, datasync);
+}
+EXPORT_SYMBOL(vfs_fsync);
-static long __do_fsync(unsigned int fd, int datasync)
+static int do_fsync(unsigned int fd, int datasync)
{
struct file *file;
int ret = -EBADF;
file = fget(fd);
if (file) {
- ret = do_fsync(file, datasync);
+ ret = vfs_fsync(file, datasync);
fput(file);
}
return ret;
}
-asmlinkage long sys_fsync(unsigned int fd)
+SYSCALL_DEFINE1(fsync, unsigned int, fd)
+{
+ return do_fsync(fd, 0);
+}
+
+SYSCALL_DEFINE1(fdatasync, unsigned int, fd)
{
- return __do_fsync(fd, 0);
+ return do_fsync(fd, 1);
}
-asmlinkage long sys_fdatasync(unsigned int fd)
+/**
+ * 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)
{
- return __do_fsync(fd, 1);
+ 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
* 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_DEFINE(sync_file_range)(int fd, loff_t offset, loff_t nbytes,
+ unsigned int flags)
{
int ret;
struct file *file;
+ struct address_space *mapping;
loff_t endbyte; /* inclusive */
int fput_needed;
umode_t 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 = 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:
+ fput_light(file, fput_needed);
out:
return ret;
}
-EXPORT_SYMBOL_GPL(do_sync_mapping_range);
+#ifdef CONFIG_HAVE_SYSCALL_WRAPPERS
+asmlinkage long SyS_sync_file_range(long fd, loff_t offset, loff_t nbytes,
+ long flags)
+{
+ return SYSC_sync_file_range((int) fd, offset, nbytes,
+ (unsigned int) flags);
+}
+SYSCALL_ALIAS(sys_sync_file_range, SyS_sync_file_range);
+#endif
+
+/* It would be nice if people remember that not all the world's an i386
+ when they introduce new system calls */
+SYSCALL_DEFINE(sync_file_range2)(int fd, unsigned int flags,
+ loff_t offset, loff_t nbytes)
+{
+ return sys_sync_file_range(fd, offset, nbytes, flags);
+}
+#ifdef CONFIG_HAVE_SYSCALL_WRAPPERS
+asmlinkage long SyS_sync_file_range2(long fd, long flags,
+ loff_t offset, loff_t nbytes)
+{
+ return SYSC_sync_file_range2((int) fd, (unsigned int) flags,
+ offset, nbytes);
+}
+SYSCALL_ALIAS(sys_sync_file_range2, SyS_sync_file_range2);
+#endif
Code Review / linux-2.6.git / blobdiff