5 files changed, 104 insertions, 0 deletions

diff --git a/fs/9p/v9fs.h b/fs/9p/v9fs.h
index 71cab8e3a570..cfdc05527f89 100644
--- a/fs/9p/v9fs.h
+++ b/fs/9p/v9fs.h
@@ -116,12 +116,16 @@ struct v9fs_session_info {
         struct p9_fid *root_fid; /* Used for file system sync */
 };
 
+/* cache_validity flags */
+#define V9FS_INO_INVALID_ATTR 0x01
+
 struct v9fs_inode {
 #ifdef CONFIG_9P_FSCACHE
         spinlock_t fscache_lock;
         struct fscache_cookie *fscache;
         struct p9_qid *fscache_key;
 #endif
+        unsigned int cache_validity;
         struct p9_fid *writeback_fid;
         struct inode vfs_inode;
 };
diff --git a/fs/9p/v9fs_vfs.h b/fs/9p/v9fs_vfs.h
index ed9fd00566f2..591807f20188 100644
--- a/fs/9p/v9fs_vfs.h
+++ b/fs/9p/v9fs_vfs.h
@@ -70,4 +70,14 @@ int v9fs_vfs_setattr_dotl(struct dentry *, struct iattr *);
 int v9fs_file_fsync_dotl(struct file *filp, int datasync);
 ssize_t v9fs_file_write_internal(struct inode *, struct p9_fid *,
                                  const char __user *, size_t, loff_t *, int);
+int v9fs_refresh_inode(struct p9_fid *fid, struct inode *inode);
+int v9fs_refresh_inode_dotl(struct p9_fid *fid, struct inode *inode);
+static inline void v9fs_invalidate_inode_attr(struct inode *inode)
+{
+        struct v9fs_inode *v9inode;
+        v9inode = V9FS_I(inode);
+        v9inode->cache_validity |= V9FS_INO_INVALID_ATTR;
+        return;
+}
+
 #define P9_LOCK_TIMEOUT (30*HZ)
diff --git a/fs/9p/vfs_dentry.c b/fs/9p/vfs_dentry.c
index a4ae4be5ab59..b6a3b9f7fe4d 100644
--- a/fs/9p/vfs_dentry.c
+++ b/fs/9p/vfs_dentry.c
@@ -100,7 +100,41 @@ static void v9fs_dentry_release(struct dentry *dentry)
         }
 }
 
+static int v9fs_lookup_revalidate(struct dentry *dentry, struct nameidata *nd)
+{
+        struct p9_fid *fid;
+        struct inode *inode;
+        struct v9fs_inode *v9inode;
+
+        if (nd->flags & LOOKUP_RCU)
+                return -ECHILD;
+
+        inode = dentry->d_inode;
+        if (!inode)
+                goto out_valid;
+
+        v9inode = V9FS_I(inode);
+        if (v9inode->cache_validity & V9FS_INO_INVALID_ATTR) {
+                int retval;
+                struct v9fs_session_info *v9ses;
+                fid = v9fs_fid_lookup(dentry);
+                if (IS_ERR(fid))
+                        return PTR_ERR(fid);
+
+                v9ses = v9fs_inode2v9ses(inode);
+                if (v9fs_proto_dotl(v9ses))
+                        retval = v9fs_refresh_inode_dotl(fid, inode);
+                else
+                        retval = v9fs_refresh_inode(fid, inode);
+                if (retval <= 0)
+                        return retval;
+        }
+out_valid:
+        return 1;
+}
+
 const struct dentry_operations v9fs_cached_dentry_operations = {
+        .d_revalidate = v9fs_lookup_revalidate,
         .d_delete = v9fs_cached_dentry_delete,
         .d_release = v9fs_dentry_release,
 };
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,
diff --git a/fs/9p/vfs_inode_dotl.c b/fs/9p/vfs_inode_dotl.c
index c6d9677dcb6e..5c04d66afb1d 100644
--- a/fs/9p/vfs_inode_dotl.c
+++ b/fs/9p/vfs_inode_dotl.c
@@ -484,6 +484,7 @@ int v9fs_vfs_setattr_dotl(struct dentry *dentry, struct iattr *iattr)
 void
 v9fs_stat2inode_dotl(struct p9_stat_dotl *stat, struct inode *inode)
 {
+        struct v9fs_inode *v9inode = V9FS_I(inode);
 
         if ((stat->st_result_mask & P9_STATS_BASIC) == P9_STATS_BASIC) {
                 inode->i_atime.tv_sec = stat->st_atime_sec;
@@ -542,6 +543,7 @@ v9fs_stat2inode_dotl(struct p9_stat_dotl *stat, struct inode *inode)
         /* Currently we don't support P9_STATS_BTIME and P9_STATS_DATA_VERSION
          * because the inode structure does not have fields for them.
          */
+        v9inode->cache_validity &= ~V9FS_INO_INVALID_ATTR;
 }
 
 static int
@@ -822,6 +824,31 @@ ndset:
         return NULL;
 }
 
+int v9fs_refresh_inode_dotl(struct p9_fid *fid, struct inode *inode)
+{
+        loff_t i_size;
+        struct p9_stat_dotl *st;
+        struct v9fs_session_info *v9ses;
+
+        v9ses = v9fs_inode2v9ses(inode);
+        st = p9_client_getattr_dotl(fid, P9_STATS_ALL);
+        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_dotl(st, inode);
+        if (v9ses->cache)
+                inode->i_size = i_size;
+        spin_unlock(&inode->i_lock);
+        kfree(st);
+        return 0;
+}
+
 const struct inode_operations v9fs_dir_inode_operations_dotl = {
         .create = v9fs_vfs_create_dotl,
         .lookup = v9fs_vfs_lookup,