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| author | Trond Myklebust <Trond.Myklebust@netapp.com> | 2012-01-18 04:04:26 +0100 |
|---|---|---|
| committer | Trond Myklebust <Trond.Myklebust@netapp.com> | 2012-02-01 01:28:07 +0100 |
| commit | 536e43d12b9517bbbf6114cd1a12be27857a4d7a (patch) | |
| tree | a40424a430fd651fe7b35232717f2201c608059a /fs/nfs/dir.c | |
| parent | NFS: Move struct nfs_unique_id into struct nfs_seqid_counter (diff) | |
| download | linux-536e43d12b9517bbbf6114cd1a12be27857a4d7a.tar.xz linux-536e43d12b9517bbbf6114cd1a12be27857a4d7a.zip | |
NFS: Optimise away unnecessary setattrs for open(O_TRUNC);
Currently, we will correctly optimise away a truncate that doesn't
change the file size. However, in the case of open(O_TRUNC), we
also want to optimise away the time changes.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Diffstat (limited to 'fs/nfs/dir.c')
| -rw-r--r-- | fs/nfs/dir.c | 25 |
1 files changed, 19 insertions, 6 deletions
diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c index fd9a872fada0..bb132a88f4e8 100644 --- a/fs/nfs/dir.c +++ b/fs/nfs/dir.c @@ -1429,6 +1429,7 @@ static struct dentry *nfs_atomic_lookup(struct inode *dir, struct dentry *dentry } open_flags = nd->intent.open.flags; + attr.ia_valid = 0; ctx = create_nfs_open_context(dentry, open_flags); res = ERR_CAST(ctx); @@ -1437,11 +1438,14 @@ static struct dentry *nfs_atomic_lookup(struct inode *dir, struct dentry *dentry if (nd->flags & LOOKUP_CREATE) { attr.ia_mode = nd->intent.open.create_mode; - attr.ia_valid = ATTR_MODE; + attr.ia_valid |= ATTR_MODE; attr.ia_mode &= ~current_umask(); - } else { + } else open_flags &= ~(O_EXCL | O_CREAT); - attr.ia_valid = 0; + + if (open_flags & O_TRUNC) { + attr.ia_valid |= ATTR_SIZE; + attr.ia_size = 0; } /* Open the file on the server */ @@ -1495,6 +1499,7 @@ static int nfs_open_revalidate(struct dentry *dentry, struct nameidata *nd) struct inode *inode; struct inode *dir; struct nfs_open_context *ctx; + struct iattr attr; int openflags, ret = 0; if (nd->flags & LOOKUP_RCU) @@ -1523,19 +1528,27 @@ static int nfs_open_revalidate(struct dentry *dentry, struct nameidata *nd) /* We cannot do exclusive creation on a positive dentry */ if ((openflags & (O_CREAT|O_EXCL)) == (O_CREAT|O_EXCL)) goto no_open_dput; - /* We can't create new files, or truncate existing ones here */ - openflags &= ~(O_CREAT|O_EXCL|O_TRUNC); + /* We can't create new files here */ + openflags &= ~(O_CREAT|O_EXCL); ctx = create_nfs_open_context(dentry, openflags); ret = PTR_ERR(ctx); if (IS_ERR(ctx)) goto out; + + attr.ia_valid = 0; + if (openflags & O_TRUNC) { + attr.ia_valid |= ATTR_SIZE; + attr.ia_size = 0; + nfs_wb_all(inode); + } + /* * Note: we're not holding inode->i_mutex and so may be racing with * operations that change the directory. We therefore save the * change attribute *before* we do the RPC call. */ - inode = NFS_PROTO(dir)->open_context(dir, ctx, openflags, NULL); + inode = NFS_PROTO(dir)->open_context(dir, ctx, openflags, &attr); if (IS_ERR(inode)) { ret = PTR_ERR(inode); switch (ret) { |