fs/9p: Add fid to inode in cached mode

The fid attached to inode will be opened O_RDWR mode and is used
for dirty page writeback only.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

diff --git a/fs/9p/fid.c b/fs/9p/fid.c
index b00223c..9d6a5d3 100644 (file)
--- a/fs/9p/fid.c
+++ b/fs/9p/fid.c
@@ -261,3 +261,29 @@ struct p9_fid *v9fs_fid_clone(struct dentry *dentry)
        ret = p9_client_walk(fid, 0, NULL, 1);
        return ret;
 }
+
+
+struct p9_fid *v9fs_writeback_fid(struct dentry *dentry)
+{
+       int err;
+       struct p9_fid *fid;
+
+       fid = v9fs_fid_clone(dentry);
+       if (IS_ERR(fid))
+               goto error_out;
+       /*
+        * writeback fid will only be used to write back the
+        * dirty pages. We always request for the open fid in read-write
+        * mode so that a partial page write which result in page
+        * read can work.
+        * FIXME!!: we should make the fid owned by uid = 0
+        */
+       err = p9_client_open(fid, O_RDWR);
+       if (err < 0) {
+               p9_client_clunk(fid);
+               fid = ERR_PTR(err);
+               goto error_out;
+       }
+error_out:
+       return fid;
+}

diff --git a/fs/9p/fid.h b/fs/9p/fid.h
index c3bbd6a..c058f1c 100644 (file)
--- a/fs/9p/fid.h
+++ b/fs/9p/fid.h
@@ -45,3 +45,4 @@ struct v9fs_dentry {
 struct p9_fid *v9fs_fid_lookup(struct dentry *dentry);
 struct p9_fid *v9fs_fid_clone(struct dentry *dentry);
 int v9fs_fid_add(struct dentry *dentry, struct p9_fid *fid);
+struct p9_fid *v9fs_writeback_fid(struct dentry *dentry);

diff --git a/fs/9p/vfs_file.c b/fs/9p/vfs_file.c
index 6e1e8f4..e966f15 100644 (file)
--- a/fs/9p/vfs_file.c
+++ b/fs/9p/vfs_file.c
@@ -86,11 +86,30 @@ int v9fs_file_open(struct inode *inode, struct file *file)
        }
 
        file->private_data = fid;
+       if (v9ses->cache && !inode->i_private) {
+               /*
+                * clone a fid and add it to inode->i_private
+                * we do it during open time instead of
+                * page dirty time via write_begin/page_mkwrite
+                * because we want write after unlink usecase
+                * to work.
+                */
+               fid = v9fs_writeback_fid(file->f_path.dentry);
+               if (IS_ERR(fid)) {
+                       err = PTR_ERR(fid);
+                       goto out_error;
+               }
+               inode->i_private = (void *) fid;
+       }
 #ifdef CONFIG_9P_FSCACHE
        if (v9ses->cache)
                v9fs_cache_inode_set_cookie(inode, file);
 #endif
        return 0;
+out_error:
+       p9_client_clunk(file->private_data);
+       file->private_data = NULL;
+       return err;
 }
 
 /**

diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c
index 95f5501..a0d65a3 100644 (file)
--- a/fs/9p/vfs_inode.c
+++ b/fs/9p/vfs_inode.c
@@ -417,6 +417,11 @@ void v9fs_evict_inode(struct inode *inode)
 #ifdef CONFIG_9P_FSCACHE
        v9fs_cache_inode_put_cookie(inode);
 #endif
+       /* clunk the fid stashed in inode->i_private */
+       if (inode->i_private) {
+               p9_client_clunk((struct p9_fid *)inode->i_private);
+               inode->i_private = NULL;
+       }
 }
 
 struct inode *
@@ -578,7 +583,7 @@ v9fs_vfs_create(struct inode *dir, struct dentry *dentry, int mode,
        u32 perm;
        int flags;
        struct v9fs_session_info *v9ses;
-       struct p9_fid *fid;
+       struct p9_fid *fid, *inode_fid;
        struct file *filp;
 
        err = 0;
@@ -601,6 +606,21 @@ v9fs_vfs_create(struct inode *dir, struct dentry *dentry, int mode,
 
        /* if we are opening a file, assign the open fid to the file */
        if (nd && nd->flags & LOOKUP_OPEN) {
+               if (v9ses->cache && !dentry->d_inode->i_private) {
+                       /*
+                        * clone a fid and add it to inode->i_private
+                        * we do it during open time instead of
+                        * page dirty time via write_begin/page_mkwrite
+                        * because we want write after unlink usecase
+                        * to work.
+                        */
+                       inode_fid = v9fs_writeback_fid(dentry);
+                       if (IS_ERR(inode_fid)) {
+                               err = PTR_ERR(inode_fid);
+                               goto error;
+                       }
+                       dentry->d_inode->i_private = (void *) inode_fid;
+               }
                filp = lookup_instantiate_filp(nd, dentry, generic_file_open);
                if (IS_ERR(filp)) {
                        err = PTR_ERR(filp);

diff --git a/fs/9p/vfs_inode_dotl.c b/fs/9p/vfs_inode_dotl.c
index 265f583..1327464 100644 (file)
--- a/fs/9p/vfs_inode_dotl.c
+++ b/fs/9p/vfs_inode_dotl.c
@@ -142,7 +142,7 @@ v9fs_vfs_create_dotl(struct inode *dir, struct dentry *dentry, int omode,
        mode_t mode;
        struct v9fs_session_info *v9ses;
        struct p9_fid *fid = NULL;
-       struct p9_fid *dfid, *ofid;
+       struct p9_fid *dfid, *ofid, *inode_fid;
        struct file *filp;
        struct p9_qid qid;
        struct inode *inode;
@@ -218,7 +218,21 @@ v9fs_vfs_create_dotl(struct inode *dir, struct dentry *dentry, int omode,
 
        /* Now set the ACL based on the default value */
        v9fs_set_create_acl(dentry, dacl, pacl);
-
+       if (v9ses->cache && !inode->i_private) {
+               /*
+                * clone a fid and add it to inode->i_private
+                * we do it during open time instead of
+                * page dirty time via write_begin/page_mkwrite
+                * because we want write after unlink usecase
+                * to work.
+                */
+               inode_fid = v9fs_writeback_fid(dentry);
+               if (IS_ERR(inode_fid)) {
+                       err = PTR_ERR(inode_fid);
+                       goto error;
+               }
+               inode->i_private = (void *) inode_fid;
+       }
        /* Since we are opening a file, assign the open fid to the file */
        filp = lookup_instantiate_filp(nd, dentry, generic_file_open);
        if (IS_ERR(filp)) {