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authorJeff Layton <jeff.layton@primarydata.com>2019-08-18 21:18:48 +0300
committerJ. Bruce Fields <bfields@redhat.com>2019-08-19 18:00:39 +0300
commit65294c1f2c5e72b15b76e16c8c8cfd9359fc9f6f (patch)
tree9b088b0f2e2fba280862b489910b1aeb0460c8c3 /fs/nfsd/vfs.c
parent7239a40ca8bfd88dc5d2f66a14882054fe8e3b92 (diff)
downloadlinux-65294c1f2c5e72b15b76e16c8c8cfd9359fc9f6f.tar.xz
nfsd: add a new struct file caching facility to nfsd
Currently, NFSv2/3 reads and writes have to open a file, do the read or write and then close it again for each RPC. This is highly inefficient, especially when the underlying filesystem has a relatively slow open routine. This patch adds a new open file cache to knfsd. Rather than doing an open for each RPC, the read/write handlers can call into this cache to see if there is one already there for the correct filehandle and NFS_MAY_READ/WRITE flags. If there isn't an entry, then we create a new one and attempt to perform the open. If there is, then we wait until the entry is fully instantiated and return it if it is at the end of the wait. If it's not, then we attempt to take over construction. Since the main goal is to speed up NFSv2/3 I/O, we don't want to close these files on last put of these objects. We need to keep them around for a little while since we never know when the next READ/WRITE will come in. Cache entries have a hardcoded 1s timeout, and we have a recurring workqueue job that walks the cache and purges any entries that have expired. Signed-off-by: Jeff Layton <jeff.layton@primarydata.com> Signed-off-by: Weston Andros Adamson <dros@primarydata.com> Signed-off-by: Richard Sharpe <richard.sharpe@primarydata.com> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Diffstat (limited to 'fs/nfsd/vfs.c')
-rw-r--r--fs/nfsd/vfs.c65
1 files changed, 43 insertions, 22 deletions
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index c85783e536d5..5983206ab036 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -699,7 +699,7 @@ nfsd_access(struct svc_rqst *rqstp, struct svc_fh *fhp, u32 *access, u32 *suppor
}
#endif /* CONFIG_NFSD_V3 */
-static int nfsd_open_break_lease(struct inode *inode, int access)
+int nfsd_open_break_lease(struct inode *inode, int access)
{
unsigned int mode;
@@ -715,8 +715,8 @@ static int nfsd_open_break_lease(struct inode *inode, int access)
* and additional flags.
* N.B. After this call fhp needs an fh_put
*/
-__be32
-nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type,
+static __be32
+__nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type,
int may_flags, struct file **filp)
{
struct path path;
@@ -726,25 +726,6 @@ nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type,
__be32 err;
int host_err = 0;
- validate_process_creds();
-
- /*
- * If we get here, then the client has already done an "open",
- * and (hopefully) checked permission - so allow OWNER_OVERRIDE
- * in case a chmod has now revoked permission.
- *
- * Arguably we should also allow the owner override for
- * directories, but we never have and it doesn't seem to have
- * caused anyone a problem. If we were to change this, note
- * also that our filldir callbacks would need a variant of
- * lookup_one_len that doesn't check permissions.
- */
- if (type == S_IFREG)
- may_flags |= NFSD_MAY_OWNER_OVERRIDE;
- err = fh_verify(rqstp, fhp, type, may_flags);
- if (err)
- goto out;
-
path.mnt = fhp->fh_export->ex_path.mnt;
path.dentry = fhp->fh_dentry;
inode = d_inode(path.dentry);
@@ -798,10 +779,50 @@ nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type,
out_nfserr:
err = nfserrno(host_err);
out:
+ return err;
+}
+
+__be32
+nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type,
+ int may_flags, struct file **filp)
+{
+ __be32 err;
+
+ validate_process_creds();
+ /*
+ * If we get here, then the client has already done an "open",
+ * and (hopefully) checked permission - so allow OWNER_OVERRIDE
+ * in case a chmod has now revoked permission.
+ *
+ * Arguably we should also allow the owner override for
+ * directories, but we never have and it doesn't seem to have
+ * caused anyone a problem. If we were to change this, note
+ * also that our filldir callbacks would need a variant of
+ * lookup_one_len that doesn't check permissions.
+ */
+ if (type == S_IFREG)
+ may_flags |= NFSD_MAY_OWNER_OVERRIDE;
+ err = fh_verify(rqstp, fhp, type, may_flags);
+ if (!err)
+ err = __nfsd_open(rqstp, fhp, type, may_flags, filp);
+ validate_process_creds();
+ return err;
+}
+
+__be32
+nfsd_open_verified(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type,
+ int may_flags, struct file **filp)
+{
+ __be32 err;
+
+ validate_process_creds();
+ err = __nfsd_open(rqstp, fhp, type, may_flags, filp);
validate_process_creds();
return err;
}
+
+
struct raparms *
nfsd_init_raparms(struct file *file)
{