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>

1 files changed, 21 insertions, 0 deletions

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