#include <linux/file.h>
#include <linux/fs.h>
#include <linux/module.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 "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)
+ 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);
+ sync_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);
+
+/*
+ * 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);
+}
+
+/*
+ * sync everything. Start out by waking pdflush, because that writes back
+ * all queues in parallel.
+ */
+SYSCALL_DEFINE0(sync)
+{
+ wakeup_flusher_threads(0);
+ sync_filesystems(0);
+ sync_filesystems(1);
+ if (unlikely(laptop_mode))
+ laptop_sync_completion();
+ return 0;
+}
+
+static void do_sync_work(struct work_struct *work)
+{
+ /*
+ * 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)
+{
+ 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)
+{
+ 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;
+ if (sb->s_dirt && sb->s_op->write_super)
+ sb->s_op->write_super(sb);
+
+ /* .. finally sync the buffers to disk */
+ err = sync_blockdev(sb->s_bdev);
+ if (!ret)
+ ret = err;
+ return ret;
+}
+EXPORT_SYMBOL(file_fsync);
+
+/**
+ * vfs_fsync_range - helper to sync a range of data & metadata to disk
+ * @file: file to sync
+ * @dentry: dentry of @file
+ * @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.
+ *
+ * In case this function is called from nfsd @file may be %NULL and
+ * only @dentry is set. This can only happen when the filesystem
+ * implements the export_operations API.
+ */
+int vfs_fsync_range(struct file *file, struct dentry *dentry, loff_t start,
+ loff_t end, int datasync)
+{
+ const struct file_operations *fop;
+ struct address_space *mapping;
+ int err, ret;
+
+ /*
+ * Get mapping and operations from the file in case we have
+ * as file, or get the default values for them in case we
+ * don't have a struct file available. Damn nfsd..
+ */
+ if (file) {
+ mapping = file->f_mapping;
+ fop = file->f_op;
+ } else {
+ mapping = dentry->d_inode->i_mapping;
+ fop = dentry->d_inode->i_fop;
+ }
+
+ if (!fop || !fop->fsync) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ 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 = fop->fsync(file, dentry, datasync);
+ if (!ret)
+ ret = err;
+ mutex_unlock(&mapping->host->i_mutex);
+
+out:
+ return ret;
+}
+EXPORT_SYMBOL(vfs_fsync_range);
+
+/**
+ * vfs_fsync - perform a fsync or fdatasync on a file
+ * @file: file to sync
+ * @dentry: dentry of @file
+ * @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.
+ *
+ * In case this function is called from nfsd @file may be %NULL and
+ * only @dentry is set. This can only happen when the filesystem
+ * implements the export_operations API.
+ */
+int vfs_fsync(struct file *file, struct dentry *dentry, int datasync)
+{
+ return vfs_fsync_range(file, dentry, 0, LLONG_MAX, datasync);
+}
+EXPORT_SYMBOL(vfs_fsync);
+
+static int do_fsync(unsigned int fd, int datasync)
+{
+ struct file *file;
+ int ret = -EBADF;
+
+ file = fget(fd);
+ if (file) {
+ ret = vfs_fsync(file, file->f_path.dentry, datasync);
+ fput(file);
+ }
+ return ret;
+}
+
+SYSCALL_DEFINE1(fsync, unsigned int, fd)
+{
+ return do_fsync(fd, 0);
+}
+
+SYSCALL_DEFINE1(fdatasync, unsigned int, fd)
+{
+ 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_SYNC) && !IS_SYNC(file->f_mapping->host))
+ return 0;
+ return vfs_fsync_range(file, file->f_path.dentry, pos,
+ pos + count - 1, 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
* zero then sys_sync_file_range() will operate from offset out to EOF.
* 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,
- int flags)
+SYSCALL_DEFINE(sync_file_range)(int fd, loff_t offset, loff_t nbytes,
+ unsigned int flags)
{
int ret;
struct file *file;
}
if (nbytes == 0)
- endbyte = -1;
+ endbyte = LLONG_MAX;
else
endbyte--; /* inclusive */
if (!file)
goto out;
- i_mode = file->f_dentry->d_inode->i_mode;
+ i_mode = 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;
- ret = do_sync_file_range(file, offset, endbyte, flags);
+ ret = do_sync_mapping_range(file->f_mapping, offset, endbyte, flags);
out_put:
fput_light(file, fput_needed);
out:
return ret;
}
+#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
/*
* `endbyte' is inclusive
*/
-int do_sync_file_range(struct file *file, loff_t offset, loff_t endbyte,
- int flags)
+int do_sync_mapping_range(struct address_space *mapping, loff_t offset,
+ loff_t endbyte, unsigned int flags)
{
int ret;
- struct address_space *mapping;
- mapping = file->f_mapping;
if (!mapping) {
ret = -EINVAL;
goto out;
if (flags & SYNC_FILE_RANGE_WRITE) {
ret = __filemap_fdatawrite_range(mapping, offset, endbyte,
- WB_SYNC_NONE);
+ WB_SYNC_ALL);
if (ret < 0)
goto out;
}
out:
return ret;
}
-EXPORT_SYMBOL_GPL(do_sync_file_range);
+EXPORT_SYMBOL_GPL(do_sync_mapping_range);
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff