From aa696a6f349638428982bb52763f4cda851632fa Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Fri, 29 Jan 2010 16:44:25 -0500 Subject: [PATCH] nfsd: Use vfs_fsync_range() in nfsd_commit The NFS COMMIT operation allows the client to specify the exact byte range that it wishes to sync to disk in order to optimise server performance. Signed-off-by: Trond Myklebust Reviewed-by: Christoph Hellwig Signed-off-by: J. Bruce Fields --- fs/nfsd/vfs.c | 30 ++++++++++++++++++++---------- 1 file changed, 20 insertions(+), 10 deletions(-) diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c index 79d216f276d9..ed024d329056 100644 --- a/fs/nfsd/vfs.c +++ b/fs/nfsd/vfs.c @@ -1141,8 +1141,9 @@ out: #ifdef CONFIG_NFSD_V3 /* * Commit all pending writes to stable storage. - * Strictly speaking, we could sync just the indicated file region here, - * but there's currently no way we can ask the VFS to do so. + * + * Note: we only guarantee that data that lies within the range specified + * by the 'offset' and 'count' parameters will be synced. * * Unfortunately we cannot lock the file to make sure we return full WCC * data to the client, as locking happens lower down in the filesystem. @@ -1152,23 +1153,32 @@ nfsd_commit(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t offset, unsigned long count) { struct file *file; - __be32 err; + loff_t end = LLONG_MAX; + __be32 err = nfserr_inval; - if ((u64)count > ~(u64)offset) - return nfserr_inval; + if (offset < 0) + goto out; + if (count != 0) { + end = offset + (loff_t)count - 1; + if (end < offset) + goto out; + } err = nfsd_open(rqstp, fhp, S_IFREG, NFSD_MAY_WRITE, &file); if (err) - return err; + goto out; if (EX_ISSYNC(fhp->fh_export)) { - if (file->f_op && file->f_op->fsync) { - err = nfserrno(vfs_fsync(file, file->f_path.dentry, 0)); - } else { + int err2 = vfs_fsync_range(file, file->f_path.dentry, + offset, end, 0); + + if (err2 != -EINVAL) + err = nfserrno(err2); + else err = nfserr_notsupp; - } } nfsd_close(file); +out: return err; } #endif /* CONFIG_NFSD_V3 */