9p: Make use of iounit for read/write

Change the v9fs_file_readn function to limit the maximum transfer size
based on the iounit or msize.

Also remove the redundant check for limiting the transfer size in
v9fs_file_write. This check is done by p9_client_write.

Signed-off-by: M. Mohan Kumar <mohan@in.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

diff --git a/fs/9p/vfs_file.c b/fs/9p/vfs_file.c
index 2bedc6c94fc2c805f407e4fb5ad7970e36f27a83..2d686ec322a085190964b97087b72f513b9e0ec6 100644 (file)
--- a/fs/9p/vfs_file.c
+++ b/fs/9p/vfs_file.c
@@ -139,7 +139,7 @@ ssize_t
 v9fs_file_readn(struct file *filp, char *data, char __user *udata, u32 count,
               u64 offset)
 {
-       int n, total;
+       int n, total, size;
        struct p9_fid *fid = filp->private_data;
 
        P9_DPRINTK(P9_DEBUG_VFS, "fid %d offset %llu count %d\n", fid->fid,
@@ -147,6 +147,7 @@ v9fs_file_readn(struct file *filp, char *data, char __user *udata, u32 count,
 
        n = 0;
        total = 0;
+       size = fid->iounit ? fid->iounit : fid->clnt->msize - P9_IOHDRSZ;
        do {
                n = p9_client_read(fid, data, udata, offset, count);
                if (n <= 0)
@@ -160,7 +161,7 @@ v9fs_file_readn(struct file *filp, char *data, char __user *udata, u32 count,
                offset += n;
                count -= n;
                total += n;
-       } while (count > 0 && n == (fid->clnt->msize - P9_IOHDRSZ));
+       } while (count > 0 && n == size);
 
        if (n < 0)
                total = n;
@@ -183,11 +184,13 @@ v9fs_file_read(struct file *filp, char __user *udata, size_t count,
 {
        int ret;
        struct p9_fid *fid;
+       size_t size;
 
        P9_DPRINTK(P9_DEBUG_VFS, "count %zu offset %lld\n", count, *offset);
        fid = filp->private_data;
 
-       if (count > (fid->clnt->msize - P9_IOHDRSZ))
+       size = fid->iounit ? fid->iounit : fid->clnt->msize - P9_IOHDRSZ;
+       if (count > size)
                ret = v9fs_file_readn(filp, NULL, udata, count, *offset);
        else
                ret = p9_client_read(fid, NULL, udata, *offset, count);
@@ -224,9 +227,7 @@ v9fs_file_write(struct file *filp, const char __user * data,
        fid = filp->private_data;
        clnt = fid->clnt;
 
-       rsize = fid->iounit;
-       if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
-               rsize = clnt->msize - P9_IOHDRSZ;
+       rsize = fid->iounit ? fid->iounit : clnt->msize - P9_IOHDRSZ;
 
        do {
                if (count < rsize)