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-rw-r--r--fs/sync.c86
1 files changed, 14 insertions, 72 deletions
diff --git a/fs/sync.c b/fs/sync.c
index de6a441..e8cbd41 100644
--- a/fs/sync.c
+++ b/fs/sync.c
@@ -77,50 +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);
}
/*
@@ -190,7 +158,6 @@ 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
@@ -198,32 +165,13 @@ EXPORT_SYMBOL(file_fsync);
* 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)
+int vfs_fsync_range(struct file *file, loff_t start, loff_t end, int datasync)
{
- const struct file_operations *fop;
- struct address_space *mapping;
+ struct address_space *mapping = file->f_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) {
+ if (!file->f_op || !file->f_op->fsync) {
ret = -EINVAL;
goto out;
}
@@ -235,7 +183,7 @@ int vfs_fsync_range(struct file *file, struct dentry *dentry, loff_t start,
* livelocks in fsync_buffers_list().
*/
mutex_lock(&mapping->host->i_mutex);
- err = fop->fsync(file, dentry, datasync);
+ err = file->f_op->fsync(file, file->f_path.dentry, datasync);
if (!ret)
ret = err;
mutex_unlock(&mapping->host->i_mutex);
@@ -248,19 +196,14 @@ 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)
+int vfs_fsync(struct file *file, int datasync)
{
- return vfs_fsync_range(file, dentry, 0, LLONG_MAX, datasync);
+ return vfs_fsync_range(file, 0, LLONG_MAX, datasync);
}
EXPORT_SYMBOL(vfs_fsync);
@@ -271,7 +214,7 @@ static int do_fsync(unsigned int fd, int datasync)
file = fget(fd);
if (file) {
- ret = vfs_fsync(file, file->f_path.dentry, datasync);
+ ret = vfs_fsync(file, datasync);
fput(file);
}
return ret;
@@ -299,8 +242,7 @@ 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, file->f_path.dentry, pos,
- pos + count - 1,
+ return vfs_fsync_range(file, pos, pos + count - 1,
(file->f_flags & __O_SYNC) ? 0 : 1);
}
EXPORT_SYMBOL(generic_write_sync);
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