fs/9p: Add support for marking inode attribute invalid

With cached mode some of the file system operation result
in updating inode attributes (ctime). Add support for
marking inode attribute invalid in such cases so that
we fetch the updated inode attribute on dentry revalidation.

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>

1 files changed, 29 insertions, 0 deletions

diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c
index 334ad12a7bbe..a28fe9fa20a4 100644
--- a/fs/9p/vfs_inode.c
+++ b/fs/9p/vfs_inode.c
@@ -220,6 +220,7 @@ struct inode *v9fs_alloc_inode(struct super_block *sb)
         spin_lock_init(&v9inode->fscache_lock);
 #endif
         v9inode->writeback_fid = NULL;
+        v9inode->cache_validity = 0;
         return &v9inode->vfs_inode;
 }
 
@@ -1010,6 +1011,7 @@ v9fs_stat2inode(struct p9_wstat *stat, struct inode *inode,
         char tag_name[14];
         unsigned int i_nlink;
         struct v9fs_session_info *v9ses = sb->s_fs_info;
+        struct v9fs_inode *v9inode = V9FS_I(inode);
 
         inode->i_nlink = 1;
 
@@ -1069,6 +1071,7 @@ v9fs_stat2inode(struct p9_wstat *stat, struct inode *inode,
 
         /* not real number of blocks, but 512 byte ones ... */
         inode->i_blocks = (i_size_read(inode) + 512 - 1) >> 9;
+        v9inode->cache_validity &= ~V9FS_INO_INVALID_ATTR;
 }
 
 /**
@@ -1323,6 +1326,32 @@ v9fs_vfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t rdev)
         return retval;
 }
 
+int v9fs_refresh_inode(struct p9_fid *fid, struct inode *inode)
+{
+        loff_t i_size;
+        struct p9_wstat *st;
+        struct v9fs_session_info *v9ses;
+
+        v9ses = v9fs_inode2v9ses(inode);
+        st = p9_client_stat(fid);
+        if (IS_ERR(st))
+                return PTR_ERR(st);
+
+        spin_lock(&inode->i_lock);
+        /*
+         * We don't want to refresh inode->i_size,
+         * because we may have cached data
+         */
+        i_size = inode->i_size;
+        v9fs_stat2inode(st, inode, inode->i_sb);
+        if (v9ses->cache)
+                inode->i_size = i_size;
+        spin_unlock(&inode->i_lock);
+        p9stat_free(st);
+        kfree(st);
+        return 0;
+}
+
 static const struct inode_operations v9fs_dir_inode_operations_dotu = {
         .create = v9fs_vfs_create,
         .lookup = v9fs_vfs_lookup,