9p: cache meta-data when cache=loose

This patch expands the impact of the loose cache mode to allow for cached
metadata increasing the performance of directory listings and other metadata
read operations.

Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

2 files changed, 15 insertions, 2 deletions

diff --git a/fs/9p/vfs_file.c b/fs/9p/vfs_file.c
index c1f7c027cfeb..2a40c2946d0a 100644
--- a/fs/9p/vfs_file.c
+++ b/fs/9p/vfs_file.c
@@ -67,10 +67,14 @@ int v9fs_file_open(struct inode *inode, struct file *file)
                         return PTR_ERR(fid);
 
                 err = p9_client_open(fid, omode);
-        if (err < 0) {
+                if (err < 0) {
                         p9_client_clunk(fid);
                         return err;
                 }
+                if (omode & P9_OTRUNC) {
+                        inode->i_size = 0;
+                        inode->i_blocks = 0;
+                }
         }
 
         file->private_data = fid;
@@ -151,6 +155,7 @@ v9fs_file_write(struct file *filp, const char __user * data,
 {
         int ret;
         struct p9_fid *fid;
+        struct inode *inode = filp->f_path.dentry->d_inode;
 
         P9_DPRINTK(P9_DEBUG_VFS, "data %p count %d offset %x\n", data,
                 (int)count, (int)*offset);
@@ -160,7 +165,12 @@ v9fs_file_write(struct file *filp, const char __user * data,
         if (ret > 0)
                 *offset += ret;
 
-        invalidate_inode_pages2(filp->f_path.dentry->d_inode->i_mapping);
+        if (*offset > inode->i_size) {
+                inode->i_size = *offset;
+                inode->i_blocks = (inode->i_size + 512 - 1) >> 9;
+        }
+
+        invalidate_inode_pages2(inode->i_mapping);
         return ret;
 }
 
diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c
index c602c0e054a2..e5c45eed58a9 100644
--- a/fs/9p/vfs_inode.c
+++ b/fs/9p/vfs_inode.c
@@ -716,6 +716,9 @@ v9fs_vfs_getattr(struct vfsmount *mnt, struct dentry *dentry,
         P9_DPRINTK(P9_DEBUG_VFS, "dentry: %p\n", dentry);
         err = -EPERM;
         v9ses = v9fs_inode2v9ses(dentry->d_inode);
+        if (v9ses->cache == CACHE_LOOSE)
+                return simple_getattr(mnt, dentry, stat);
+
         fid = v9fs_fid_lookup(dentry);
         if (IS_ERR(fid))
                 return PTR_ERR(fid);