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@xxxxxxxxxx>
---
fs/nfs/dir.c | 25 +++++++++++++++++++------
fs/nfs/inode.c | 4 ++--
fs/nfs/nfs4proc.c | 10 +++++++---
3 files changed, 28 insertions(+), 11 deletions(-)
diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index fd9a872..bb132a8 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) {
diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index 577ad5a..65486e6 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -402,7 +402,7 @@ out_no_inode:
goto out;
}
-#define NFS_VALID_ATTRS (ATTR_MODE|ATTR_UID|ATTR_GID|ATTR_SIZE|ATTR_ATIME|ATTR_ATIME_SET|ATTR_MTIME|ATTR_MTIME_SET|ATTR_FILE)
+#define NFS_VALID_ATTRS (ATTR_MODE|ATTR_UID|ATTR_GID|ATTR_SIZE|ATTR_ATIME|ATTR_ATIME_SET|ATTR_MTIME|ATTR_MTIME_SET|ATTR_FILE|ATTR_OPEN)
int
nfs_setattr(struct dentry *dentry, struct iattr *attr)
@@ -424,7 +424,7 @@ nfs_setattr(struct dentry *dentry, struct iattr *attr)
/* Optimization: if the end result is no change, don't RPC */
attr->ia_valid &= NFS_VALID_ATTRS;
- if ((attr->ia_valid & ~ATTR_FILE) == 0)
+ if ((attr->ia_valid & ~(ATTR_FILE|ATTR_OPEN)) == 0)
return 0;
/* Write all dirty data */
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 7d431d7..0c71981 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -830,7 +830,7 @@ static struct nfs4_opendata *nfs4_opendata_alloc(struct dentry *dentry,
p->o_arg.bitmask = server->attr_bitmask;
p->o_arg.dir_bitmask = server->cache_consistency_bitmask;
p->o_arg.claim = NFS4_OPEN_CLAIM_NULL;
- if (flags & O_CREAT) {
+ if (attrs != NULL && attrs->ia_valid != 0) {
u32 *s;
p->o_arg.u.attrs = &p->attrs;
@@ -887,7 +887,7 @@ static int can_open_cached(struct nfs4_state *state, fmode_t mode, int open_mode
{
int ret = 0;
- if (open_mode & O_EXCL)
+ if (open_mode & (O_EXCL|O_TRUNC))
goto out;
switch (mode & (FMODE_READ|FMODE_WRITE)) {
case FMODE_READ:
@@ -1035,7 +1035,7 @@ static struct nfs4_state *nfs4_try_open_cached(struct nfs4_opendata *opendata)
struct nfs4_state *state = opendata->state;
struct nfs_inode *nfsi = NFS_I(state->inode);
struct nfs_delegation *delegation;
- int open_mode = opendata->o_arg.open_flags & O_EXCL;
+ int open_mode = opendata->o_arg.open_flags & (O_EXCL|O_TRUNC);
fmode_t fmode = opendata->o_arg.fmode;
nfs4_stateid stateid;
int ret = -EAGAIN;
@@ -2432,6 +2432,10 @@ nfs4_proc_setattr(struct dentry *dentry, struct nfs_fattr *fattr,
}
}
+ /* Deal with open(O_TRUNC) */
+ if (attr->ia_valid & ATTR_OPEN)
+ attr->ia_valid &= ~(ATTR_MTIME|ATTR_CTIME|ATTR_OPEN);
+
status = nfs4_do_setattr(inode, cred, fattr, sattr, state);
if (status == 0)
nfs_setattr_update_inode(inode, sattr);
--
1.7.7.5
--
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