commit_metadata export operation replacing nfsd_sync_dir
- 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 <bpm@sgi.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
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 <linux/jhash.h>
#include <linux/ima.h>
#include <asm/uaccess.h>
+#include <linux/exportfs.h>
+#include <linux/writeback.h>
#ifdef CONFIG_NFSD_V3
#include "xdr3.h"
@@ -271,6 +273,32 @@
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 @@
}
/*
- * 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 @@
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 @@
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 @@
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 @@
}
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 @@
}
} 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 @@
}
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 @@
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 @@
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);