From: Ben Myers Subject: [PATCH 1/2] commit_metadata export operation replacing nfsd_sync_dir Date: Wed, 17 Feb 2010 14:05:11 -0600 Message-ID: <20100217200511.13409.75530.stgit@case> References: <20100217200426.13409.32688.stgit@case> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Cc: linux-nfs@vger.kernel.org, xfs@oss.sgi.com To: bfields@fieldses.org Return-path: Received: from relay3.sgi.com ([192.48.152.1]:49892 "EHLO relay.sgi.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754576Ab0BQUFP (ORCPT ); Wed, 17 Feb 2010 15:05:15 -0500 In-Reply-To: <20100217200426.13409.32688.stgit@case> Sender: linux-nfs-owner@vger.kernel.org List-ID: - Add commit_metadata export_operation to allow the underlying filesystem to decide how to commit an inode most efficiently. - Usage of nfsd_sync_dir and write_inode_now has been replaced with the commit_metadata function that takes a svc_fh. - The commit_metadata function calls the commit_metadata export_op if it's there, or else falls back to sync_inode instead of fsync and write_inode_now because only metadata need be synced here. - nfsd4_sync_rec_dir now uses vfs_fsync so that commit_metadata can be static Signed-off-by: Ben Myers --- fs/nfsd/nfs4recover.c | 4 -- fs/nfsd/vfs.c | 106 +++++++++++++++++++++++----------------------- include/linux/exportfs.h | 5 ++ 3 files changed, 58 insertions(+), 57 deletions(-) diff --git a/fs/nfsd/nfs4recover.c b/fs/nfsd/nfs4recover.c index 5a754f7..98fb98e 100644 --- a/fs/nfsd/nfs4recover.c +++ b/fs/nfsd/nfs4recover.c @@ -119,9 +119,7 @@ out_no_tfm: static void nfsd4_sync_rec_dir(void) { - mutex_lock(&rec_dir.dentry->d_inode->i_mutex); - nfsd_sync_dir(rec_dir.dentry); - mutex_unlock(&rec_dir.dentry->d_inode->i_mutex); + vfs_fsync(NULL, rec_dir.dentry, 0); } int diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c index ed024d3..8afdba5 100644 --- a/fs/nfsd/vfs.c +++ b/fs/nfsd/vfs.c @@ -27,6 +27,8 @@ #include #include #include +#include +#include #ifdef CONFIG_NFSD_V3 #include "xdr3.h" @@ -271,6 +273,32 @@ out: return err; } +/* + * Commit metadata changes to stable storage. + */ +static int +commit_metadata(struct svc_fh *fhp) +{ + struct inode *inode = fhp->fh_dentry->d_inode; + const struct export_operations *export_ops = inode->i_sb->s_export_op; + int error = 0; + + if (!EX_ISSYNC(fhp->fh_export)) + return 0; + + if (export_ops->commit_metadata) { + error = export_ops->commit_metadata(inode); + } else { + struct writeback_control wbc = { + .sync_mode = WB_SYNC_ALL, + .nr_to_write = 0, /* metadata only */ + }; + + error = sync_inode(inode, &wbc); + } + + return error; +} /* * Set various file attributes. @@ -769,28 +797,6 @@ nfsd_close(struct file *filp) } /* - * Sync a directory to disk. - * - * We can't just call vfs_fsync because our requirements are slightly odd: - * - * a) we do not have a file struct available - * b) we expect to have i_mutex already held by the caller - */ -int -nfsd_sync_dir(struct dentry *dentry) -{ - struct inode *inode = dentry->d_inode; - int error; - - WARN_ON(!mutex_is_locked(&inode->i_mutex)); - - error = filemap_write_and_wait(inode->i_mapping); - if (!error && inode->i_fop->fsync) - error = inode->i_fop->fsync(NULL, dentry, 0); - return error; -} - -/* * Obtain the readahead parameters for the file * specified by (dev, ino). */ @@ -1331,12 +1337,14 @@ nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp, goto out_nfserr; } - if (EX_ISSYNC(fhp->fh_export)) { - err = nfserrno(nfsd_sync_dir(dentry)); - write_inode_now(dchild->d_inode, 1); - } + err = nfsd_create_setattr(rqstp, resfhp, iap); - err2 = nfsd_create_setattr(rqstp, resfhp, iap); + /* + * nfsd_setattr already committed the child. Transactional filesystems + * had a chance to commit changes for both parent and child + * simultaneously making the following commit_metadata a noop. + */ + err2 = nfserrno(commit_metadata(fhp)); if (err2) err = err2; mnt_drop_write(fhp->fh_export->ex_path.mnt); @@ -1368,7 +1376,6 @@ nfsd_create_v3(struct svc_rqst *rqstp, struct svc_fh *fhp, struct dentry *dentry, *dchild = NULL; struct inode *dirp; __be32 err; - __be32 err2; int host_err; __u32 v_mtime=0, v_atime=0; @@ -1463,11 +1470,6 @@ nfsd_create_v3(struct svc_rqst *rqstp, struct svc_fh *fhp, if (created) *created = 1; - if (EX_ISSYNC(fhp->fh_export)) { - err = nfserrno(nfsd_sync_dir(dentry)); - /* setattr will sync the child (or not) */ - } - nfsd_check_ignore_resizing(iap); if (createmode == NFS3_CREATE_EXCLUSIVE) { @@ -1482,9 +1484,13 @@ nfsd_create_v3(struct svc_rqst *rqstp, struct svc_fh *fhp, } set_attr: - err2 = nfsd_create_setattr(rqstp, resfhp, iap); - if (err2) - err = err2; + err = nfsd_create_setattr(rqstp, resfhp, iap); + + /* + * nfsd_setattr already committed the child (and possibly also the parent). + */ + if (!err) + err = nfserrno(commit_metadata(fhp)); mnt_drop_write(fhp->fh_export->ex_path.mnt); /* @@ -1599,12 +1605,9 @@ nfsd_symlink(struct svc_rqst *rqstp, struct svc_fh *fhp, } } else host_err = vfs_symlink(dentry->d_inode, dnew, path); - - if (!host_err) { - if (EX_ISSYNC(fhp->fh_export)) - host_err = nfsd_sync_dir(dentry); - } err = nfserrno(host_err); + if (!err) + err = nfserrno(commit_metadata(fhp)); fh_unlock(fhp); mnt_drop_write(fhp->fh_export->ex_path.mnt); @@ -1666,11 +1669,9 @@ nfsd_link(struct svc_rqst *rqstp, struct svc_fh *ffhp, } host_err = vfs_link(dold, dirp, dnew); if (!host_err) { - if (EX_ISSYNC(ffhp->fh_export)) { - err = nfserrno(nfsd_sync_dir(ddir)); - write_inode_now(dest, 1); - } - err = 0; + err = nfserrno(commit_metadata(ffhp)); + if (!err) + err = nfserrno(commit_metadata(tfhp)); } else { if (host_err == -EXDEV && rqstp->rq_vers == 2) err = nfserr_acces; @@ -1766,10 +1767,10 @@ nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen, goto out_dput_new; host_err = vfs_rename(fdir, odentry, tdir, ndentry); - if (!host_err && EX_ISSYNC(tfhp->fh_export)) { - host_err = nfsd_sync_dir(tdentry); + if (!host_err) { + host_err = commit_metadata(tfhp); if (!host_err) - host_err = nfsd_sync_dir(fdentry); + host_err = commit_metadata(ffhp); } mnt_drop_write(ffhp->fh_export->ex_path.mnt); @@ -1850,12 +1851,9 @@ nfsd_unlink(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, dput(rdentry); - if (host_err) - goto out_drop; - if (EX_ISSYNC(fhp->fh_export)) - host_err = nfsd_sync_dir(dentry); + if (!host_err) + host_err = commit_metadata(fhp); -out_drop: mnt_drop_write(fhp->fh_export->ex_path.mnt); out_nfserr: err = nfserrno(host_err); diff --git a/include/linux/exportfs.h b/include/linux/exportfs.h index dc12f41..a9cd507 100644 --- a/include/linux/exportfs.h +++ b/include/linux/exportfs.h @@ -96,6 +96,7 @@ struct fid { * @fh_to_parent: find the implied object's parent and get a dentry for it * @get_name: find the name for a given inode in a given directory * @get_parent: find the parent of a given directory + * @commit_metadata: commit metadata changes to stable storage * * See Documentation/filesystems/nfs/Exporting for details on how to use * this interface correctly. @@ -137,6 +138,9 @@ struct fid { * is also a directory. In the event that it cannot be found, or storage * space cannot be allocated, a %ERR_PTR should be returned. * + * commit_metadata: + * @commit_metadata should commit metadata changes to stable storage. + * * Locking rules: * get_parent is called with child->d_inode->i_mutex down * get_name is not (which is possibly inconsistent) @@ -152,6 +156,7 @@ struct export_operations { int (*get_name)(struct dentry *parent, char *name, struct dentry *child); struct dentry * (*get_parent)(struct dentry *child); + int (*commit_metadata)(struct inode *inode); }; extern int exportfs_encode_fh(struct dentry *dentry, struct fid *fid,