nfsd: Add ALLOCATE support

The ALLOCATE operation is used to preallocate space in a file.  I can do
this by using vfs_fallocate() to do the actual preallocation.

ALLOCATE only returns a status indicator, so we don't need to write a
special encode() function.

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

5 files changed, 85 insertions, 1 deletions

diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index 0beb023f25ac..a261f1800922 100644
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -1014,6 +1014,36 @@ nfsd4_write(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
 }
 
 static __be32
+nfsd4_fallocate(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+                struct nfsd4_fallocate *fallocate, int flags)
+{
+        __be32 status = nfserr_notsupp;
+        struct file *file;
+
+        status = nfs4_preprocess_stateid_op(SVC_NET(rqstp), cstate,
+                                            &fallocate->falloc_stateid,
+                                            WR_STATE, &file);
+        if (status != nfs_ok) {
+                dprintk("NFSD: nfsd4_fallocate: couldn't process stateid!\n");
+                return status;
+        }
+
+        status = nfsd4_vfs_fallocate(rqstp, &cstate->current_fh, file,
+                                     fallocate->falloc_offset,
+                                     fallocate->falloc_length,
+                                     flags);
+        fput(file);
+        return status;
+}
+
+static __be32
+nfsd4_allocate(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+               struct nfsd4_fallocate *fallocate)
+{
+        return nfsd4_fallocate(rqstp, cstate, fallocate, 0);
+}
+
+static __be32
 nfsd4_seek(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
                 struct nfsd4_seek *seek)
 {
@@ -1929,6 +1959,12 @@ static struct nfsd4_operation nfsd4_ops[] = {
         },
 
         /* NFSv4.2 operations */
+        [OP_ALLOCATE] = {
+                .op_func = (nfsd4op_func)nfsd4_allocate,
+                .op_flags = OP_MODIFIES_SOMETHING | OP_CACHEME,
+                .op_name = "OP_ALLOCATE",
+                .op_rsize_bop = (nfsd4op_rsize)nfsd4_write_rsize,
+        },
         [OP_SEEK] = {
                 .op_func = (nfsd4op_func)nfsd4_seek,
                 .op_name = "OP_SEEK",
diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index eeea7a90eb87..a60cff86fc28 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -1514,6 +1514,23 @@ static __be32 nfsd4_decode_reclaim_complete(struct nfsd4_compoundargs *argp, str
 }
 
 static __be32
+nfsd4_decode_fallocate(struct nfsd4_compoundargs *argp,
+                       struct nfsd4_fallocate *fallocate)
+{
+        DECODE_HEAD;
+
+        status = nfsd4_decode_stateid(argp, &fallocate->falloc_stateid);
+        if (status)
+                return status;
+
+        READ_BUF(16);
+        p = xdr_decode_hyper(p, &fallocate->falloc_offset);
+        xdr_decode_hyper(p, &fallocate->falloc_length);
+
+        DECODE_TAIL;
+}
+
+static __be32
 nfsd4_decode_seek(struct nfsd4_compoundargs *argp, struct nfsd4_seek *seek)
 {
         DECODE_HEAD;
@@ -1604,7 +1621,7 @@ static nfsd4_dec nfsd4_dec_ops[] = {
         [OP_RECLAIM_COMPLETE]   = (nfsd4_dec)nfsd4_decode_reclaim_complete,
 
         /* new operations for NFSv4.2 */
-        [OP_ALLOCATE]           = (nfsd4_dec)nfsd4_decode_notsupp,
+        [OP_ALLOCATE]           = (nfsd4_dec)nfsd4_decode_fallocate,
         [OP_COPY]               = (nfsd4_dec)nfsd4_decode_notsupp,
         [OP_COPY_NOTIFY]        = (nfsd4_dec)nfsd4_decode_notsupp,
         [OP_DEALLOCATE]         = (nfsd4_dec)nfsd4_decode_notsupp,
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index d16076bd9a7a..f1999619d516 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -16,6 +16,7 @@
 #include <linux/fs.h>
 #include <linux/file.h>
 #include <linux/splice.h>
+#include <linux/falloc.h>
 #include <linux/fcntl.h>
 #include <linux/namei.h>
 #include <linux/delay.h>
@@ -533,6 +534,26 @@ __be32 nfsd4_set_nfs4_label(struct svc_rqst *rqstp, struct svc_fh *fhp,
 }
 #endif
 
+__be32 nfsd4_vfs_fallocate(struct svc_rqst *rqstp, struct svc_fh *fhp,
+                           struct file *file, loff_t offset, loff_t len,
+                           int flags)
+{
+        __be32 err;
+        int error;
+
+        if (!S_ISREG(file_inode(file)->i_mode))
+                return nfserr_inval;
+
+        err = nfsd_permission(rqstp, fhp->fh_export, fhp->fh_dentry, NFSD_MAY_WRITE);
+        if (err)
+                return err;
+
+        error = vfs_fallocate(file, flags, offset, len);
+        if (!error)
+                error = commit_metadata(fhp);
+
+        return nfserrno(error);
+}
 #endif /* defined(CONFIG_NFSD_V4) */
 
 #ifdef CONFIG_NFSD_V3
diff --git a/fs/nfsd/vfs.h b/fs/nfsd/vfs.h
index c2ff3f14e5f6..7ffdb144e486 100644
--- a/fs/nfsd/vfs.h
+++ b/fs/nfsd/vfs.h
@@ -54,6 +54,8 @@ int nfsd_mountpoint(struct dentry *, struct svc_export *);
 #ifdef CONFIG_NFSD_V4
 __be32          nfsd4_set_nfs4_label(struct svc_rqst *, struct svc_fh *,
                     struct xdr_netobj *);
+__be32          nfsd4_vfs_fallocate(struct svc_rqst *, struct svc_fh *,
+                                    struct file *, loff_t, loff_t, int);
 #endif /* CONFIG_NFSD_V4 */
 __be32          nfsd_create(struct svc_rqst *, struct svc_fh *,
                                 char *name, int len, struct iattr *attrs,
diff --git a/fs/nfsd/xdr4.h b/fs/nfsd/xdr4.h
index 5720e9457f33..eeaa0d0c4f79 100644
--- a/fs/nfsd/xdr4.h
+++ b/fs/nfsd/xdr4.h
@@ -428,6 +428,13 @@ struct nfsd4_reclaim_complete {
         u32 rca_one_fs;
 };
 
+struct nfsd4_fallocate {
+        /* request */
+        stateid_t       falloc_stateid;
+        loff_t          falloc_offset;
+        u64             falloc_length;
+};
+
 struct nfsd4_seek {
         /* request */
         stateid_t       seek_stateid;
@@ -486,6 +493,7 @@ struct nfsd4_op {
                 struct nfsd4_free_stateid       free_stateid;
 
                 /* NFSv4.2 */
+                struct nfsd4_fallocate          allocate;
                 struct nfsd4_seek               seek;
         } u;
         struct nfs4_replay *                    replay;