nfsd4: separate splice and readv cases

The splice and readv cases are actually quite different--for example the
former case ignores the array of vectors we build up for the latter.

It is probably clearer to separate the two cases entirely.

There's some code duplication between the split out encoders, but this
is only temporary and will be fixed by a later patch.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>

1 files changed, 75 insertions, 46 deletions

diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index f3a0f6cc4298..b7d35a4afefb 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -820,41 +820,54 @@ static int nfsd_direct_splice_actor(struct pipe_inode_info *pipe,
         return __splice_from_pipe(pipe, sd, nfsd_splice_actor);
 }
 
-static __be32
-nfsd_vfs_read(struct svc_rqst *rqstp, struct file *file,
-              loff_t offset, struct kvec *vec, int vlen, unsigned long *count)
+__be32 nfsd_finish_read(struct file *file, unsigned long *count, int host_err)
 {
-        mm_segment_t    oldfs;
-        __be32          err;
-        int             host_err;
-
-        err = nfserr_perm;
-
-        if (file->f_op->splice_read && rqstp->rq_splice_ok) {
-                struct splice_desc sd = {
-                        .len            = 0,
-                        .total_len      = *count,
-                        .pos            = offset,
-                        .u.data         = rqstp,
-                };
-
-                rqstp->rq_next_page = rqstp->rq_respages + 1;
-                host_err = splice_direct_to_actor(file, &sd, nfsd_direct_splice_actor);
-        } else {
-                oldfs = get_fs();
-                set_fs(KERNEL_DS);
-                host_err = vfs_readv(file, (struct iovec __user *)vec, vlen, &offset);
-                set_fs(oldfs);
-        }
-
         if (host_err >= 0) {
                 nfsdstats.io_read += host_err;
                 *count = host_err;
-                err = 0;
                 fsnotify_access(file);
+                return 0;
         } else 
-                err = nfserrno(host_err);
-        return err;
+                return nfserrno(host_err);
+}
+
+int nfsd_splice_read(struct svc_rqst *rqstp,
+                     struct file *file, loff_t offset, unsigned long *count)
+{
+        struct splice_desc sd = {
+                .len            = 0,
+                .total_len      = *count,
+                .pos            = offset,
+                .u.data         = rqstp,
+        };
+        int host_err;
+
+        rqstp->rq_next_page = rqstp->rq_respages + 1;
+        host_err = splice_direct_to_actor(file, &sd, nfsd_direct_splice_actor);
+        return nfsd_finish_read(file, count, host_err);
+}
+
+int nfsd_readv(struct file *file, loff_t offset, struct kvec *vec, int vlen,
+                unsigned long *count)
+{
+        mm_segment_t oldfs;
+        int host_err;
+
+        oldfs = get_fs();
+        set_fs(KERNEL_DS);
+        host_err = vfs_readv(file, (struct iovec __user *)vec, vlen, &offset);
+        set_fs(oldfs);
+        return nfsd_finish_read(file, count, host_err);
+}
+
+static __be32
+nfsd_vfs_read(struct svc_rqst *rqstp, struct file *file,
+              loff_t offset, struct kvec *vec, int vlen, unsigned long *count)
+{
+        if (file->f_op->splice_read && rqstp->rq_splice_ok)
+                return nfsd_splice_read(rqstp, file, offset, count);
+        else
+                return nfsd_readv(file, offset, vec, vlen, count);
 }
 
 /*
@@ -956,33 +969,28 @@ out_nfserr:
         return err;
 }
 
-/*
- * Read data from a file. count must contain the requested read count
- * on entry. On return, *count contains the number of bytes actually read.
- * N.B. After this call fhp needs an fh_put
- */
-__be32 nfsd_read(struct svc_rqst *rqstp, struct svc_fh *fhp,
-        loff_t offset, struct kvec *vec, int vlen, unsigned long *count)
+__be32 nfsd_get_tmp_read_open(struct svc_rqst *rqstp, struct svc_fh *fhp,
+                struct file **file, struct raparms **ra)
 {
-        struct file *file;
         struct inode *inode;
-        struct raparms  *ra;
         __be32 err;
 
-        err = nfsd_open(rqstp, fhp, S_IFREG, NFSD_MAY_READ, &file);
+        err = nfsd_open(rqstp, fhp, S_IFREG, NFSD_MAY_READ, file);
         if (err)
                 return err;
 
-        inode = file_inode(file);
+        inode = file_inode(*file);
 
         /* Get readahead parameters */
-        ra = nfsd_get_raparms(inode->i_sb->s_dev, inode->i_ino);
-
-        if (ra && ra->p_set)
-                file->f_ra = ra->p_ra;
+        *ra = nfsd_get_raparms(inode->i_sb->s_dev, inode->i_ino);
 
-        err = nfsd_vfs_read(rqstp, file, offset, vec, vlen, count);
+        if (*ra && (*ra)->p_set)
+                (*file)->f_ra = (*ra)->p_ra;
+        return nfs_ok;
+}
 
+void nfsd_put_tmp_read_open(struct file *file, struct raparms *ra)
+{
         /* Write back readahead params */
         if (ra) {
                 struct raparm_hbucket *rab = &raparm_hash[ra->p_hindex];
@@ -992,8 +1000,29 @@ __be32 nfsd_read(struct svc_rqst *rqstp, struct svc_fh *fhp,
                 ra->p_count--;
                 spin_unlock(&rab->pb_lock);
         }
-
         nfsd_close(file);
+}
+
+/*
+ * Read data from a file. count must contain the requested read count
+ * on entry. On return, *count contains the number of bytes actually read.
+ * N.B. After this call fhp needs an fh_put
+ */
+__be32 nfsd_read(struct svc_rqst *rqstp, struct svc_fh *fhp,
+        loff_t offset, struct kvec *vec, int vlen, unsigned long *count)
+{
+        struct file *file;
+        struct raparms  *ra;
+        __be32 err;
+
+        err = nfsd_get_tmp_read_open(rqstp, fhp, &file, &ra);
+        if (err)
+                return err;
+
+        err = nfsd_vfs_read(rqstp, file, offset, vec, vlen, count);
+
+        nfsd_put_tmp_read_open(file, ra);
+
         return err;
 }