fs/9p: Don't update file type when updating file attributes

commit 45089142b1497dab2327d60f6c71c40766fc3ea4 upstream.

We should only update attributes that we can change on stat2inode.
Also do file type initialization in v9fs_init_inode.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

4 files changed, 68 insertions, 52 deletions

diff --git a/fs/9p/v9fs_vfs.h b/fs/9p/v9fs_vfs.h
index 4014160903a..bd86d22ad91 100644
--- a/fs/9p/v9fs_vfs.h
+++ b/fs/9p/v9fs_vfs.h
@@ -54,9 +54,9 @@ extern struct kmem_cache *v9fs_inode_cache;
 
 struct inode *v9fs_alloc_inode(struct super_block *sb);
 void v9fs_destroy_inode(struct inode *inode);
-struct inode *v9fs_get_inode(struct super_block *sb, int mode);
+struct inode *v9fs_get_inode(struct super_block *sb, int mode, dev_t);
 int v9fs_init_inode(struct v9fs_session_info *v9ses,
-                    struct inode *inode, int mode);
+                    struct inode *inode, int mode, dev_t);
 void v9fs_evict_inode(struct inode *inode);
 ino_t v9fs_qid2ino(struct p9_qid *qid);
 void v9fs_stat2inode(struct p9_wstat *, struct inode *, struct super_block *);
diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c
index ad7aae4b03d..1ab561d3aa2 100644
--- a/fs/9p/vfs_inode.c
+++ b/fs/9p/vfs_inode.c
@@ -95,15 +95,18 @@ static int unixmode2p9mode(struct v9fs_session_info *v9ses, int mode)
 /**
  * p9mode2unixmode- convert plan9 mode bits to unix mode bits
  * @v9ses: v9fs session information
- * @mode: mode to convert
+ * @stat: p9_wstat from which mode need to be derived
+ * @rdev: major number, minor number in case of device files.
  *
  */
-
-static int p9mode2unixmode(struct v9fs_session_info *v9ses, int mode)
+static int p9mode2unixmode(struct v9fs_session_info *v9ses,
+                           struct p9_wstat *stat, dev_t *rdev)
 {
         int res;
+        int mode = stat->mode;
 
-        res = mode & 0777;
+        res = mode & S_IALLUGO;
+        *rdev = 0;
 
         if ((mode & P9_DMDIR) == P9_DMDIR)
                 res |= S_IFDIR;
@@ -116,9 +119,26 @@ static int p9mode2unixmode(struct v9fs_session_info *v9ses, int mode)
                  && (v9ses->nodev == 0))
                 res |= S_IFIFO;
         else if ((mode & P9_DMDEVICE) && (v9fs_proto_dotu(v9ses))
-                 && (v9ses->nodev == 0))
-                res |= S_IFBLK;
-        else
+                 && (v9ses->nodev == 0)) {
+                char type = 0, ext[32];
+                int major = -1, minor = -1;
+
+                strncpy(ext, stat->extension, sizeof(ext));
+                sscanf(ext, "%c %u %u", &type, &major, &minor);
+                switch (type) {
+                case 'c':
+                        res |= S_IFCHR;
+                        break;
+                case 'b':
+                        res |= S_IFBLK;
+                        break;
+                default:
+                        P9_DPRINTK(P9_DEBUG_ERROR,
+                                "Unknown special type %c %s\n", type,
+                                stat->extension);
+                };
+                *rdev = MKDEV(major, minor);
+        } else
                 res |= S_IFREG;
 
         if (v9fs_proto_dotu(v9ses)) {
@@ -131,7 +151,6 @@ static int p9mode2unixmode(struct v9fs_session_info *v9ses, int mode)
                 if ((mode & P9_DMSETVTX) == P9_DMSETVTX)
                         res |= S_ISVTX;
         }
-
         return res;
 }
 
@@ -242,13 +261,13 @@ void v9fs_destroy_inode(struct inode *inode)
 }
 
 int v9fs_init_inode(struct v9fs_session_info *v9ses,
-                    struct inode *inode, int mode)
+                    struct inode *inode, int mode, dev_t rdev)
 {
         int err = 0;
 
         inode_init_owner(inode, NULL, mode);
         inode->i_blocks = 0;
-        inode->i_rdev = 0;
+        inode->i_rdev = rdev;
         inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
         inode->i_mapping->a_ops = &v9fs_addr_operations;
 
@@ -335,7 +354,7 @@ error:
  *
  */
 
-struct inode *v9fs_get_inode(struct super_block *sb, int mode)
+struct inode *v9fs_get_inode(struct super_block *sb, int mode, dev_t rdev)
 {
         int err;
         struct inode *inode;
@@ -348,7 +367,7 @@ struct inode *v9fs_get_inode(struct super_block *sb, int mode)
                 P9_EPRINTK(KERN_WARNING, "Problem allocating inode\n");
                 return ERR_PTR(-ENOMEM);
         }
-        err = v9fs_init_inode(v9ses, inode, mode);
+        err = v9fs_init_inode(v9ses, inode, mode, rdev);
         if (err) {
                 iput(inode);
                 return ERR_PTR(err);
@@ -435,11 +454,12 @@ void v9fs_evict_inode(struct inode *inode)
 static int v9fs_test_inode(struct inode *inode, void *data)
 {
         int umode;
+        dev_t rdev;
         struct v9fs_inode *v9inode = V9FS_I(inode);
         struct p9_wstat *st = (struct p9_wstat *)data;
         struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode);
 
-        umode = p9mode2unixmode(v9ses, st->mode);
+        umode = p9mode2unixmode(v9ses, st, &rdev);
         /* don't match inode of different type */
         if ((inode->i_mode & S_IFMT) != (umode & S_IFMT))
                 return 0;
@@ -473,6 +493,7 @@ static struct inode *v9fs_qid_iget(struct super_block *sb,
                                    struct p9_wstat *st,
                                    int new)
 {
+        dev_t rdev;
         int retval, umode;
         unsigned long i_ino;
         struct inode *inode;
@@ -496,8 +517,8 @@ static struct inode *v9fs_qid_iget(struct super_block *sb,
          * later.
          */
         inode->i_ino = i_ino;
-        umode = p9mode2unixmode(v9ses, st->mode);
-        retval = v9fs_init_inode(v9ses, inode, umode);
+        umode = p9mode2unixmode(v9ses, st, &rdev);
+        retval = v9fs_init_inode(v9ses, inode, umode, rdev);
         if (retval)
                 goto error;
 
@@ -990,7 +1011,7 @@ v9fs_vfs_getattr(struct vfsmount *mnt, struct dentry *dentry,
                 return PTR_ERR(st);
 
         v9fs_stat2inode(st, dentry->d_inode, dentry->d_inode->i_sb);
-                generic_fillattr(dentry->d_inode, stat);
+        generic_fillattr(dentry->d_inode, stat);
 
         p9stat_free(st);
         kfree(st);
@@ -1074,6 +1095,7 @@ void
 v9fs_stat2inode(struct p9_wstat *stat, struct inode *inode,
         struct super_block *sb)
 {
+        mode_t mode;
         char ext[32];
         char tag_name[14];
         unsigned int i_nlink;
@@ -1109,31 +1131,9 @@ v9fs_stat2inode(struct p9_wstat *stat, struct inode *inode,
                                 inode->i_nlink = i_nlink;
                 }
         }
-        inode->i_mode = p9mode2unixmode(v9ses, stat->mode);
-        if ((S_ISBLK(inode->i_mode)) || (S_ISCHR(inode->i_mode))) {
-                char type = 0;
-                int major = -1;
-                int minor = -1;
-
-                strncpy(ext, stat->extension, sizeof(ext));
-                sscanf(ext, "%c %u %u", &type, &major, &minor);
-                switch (type) {
-                case 'c':
-                        inode->i_mode &= ~S_IFBLK;
-                        inode->i_mode |= S_IFCHR;
-                        break;
-                case 'b':
-                        break;
-                default:
-                        P9_DPRINTK(P9_DEBUG_ERROR,
-                                "Unknown special type %c %s\n", type,
-                                stat->extension);
-                };
-                inode->i_rdev = MKDEV(major, minor);
-                init_special_inode(inode, inode->i_mode, inode->i_rdev);
-        } else
-                inode->i_rdev = 0;
-
+        mode = stat->mode & S_IALLUGO;
+        mode |= inode->i_mode & ~S_IALLUGO;
+        inode->i_mode = mode;
         i_size_write(inode, stat->length);
 
         /* not real number of blocks, but 512 byte ones ... */
@@ -1399,6 +1399,8 @@ v9fs_vfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t rdev)
 
 int v9fs_refresh_inode(struct p9_fid *fid, struct inode *inode)
 {
+        int umode;
+        dev_t rdev;
         loff_t i_size;
         struct p9_wstat *st;
         struct v9fs_session_info *v9ses;
@@ -1407,6 +1409,12 @@ int v9fs_refresh_inode(struct p9_fid *fid, struct inode *inode)
         st = p9_client_stat(fid);
         if (IS_ERR(st))
                 return PTR_ERR(st);
+        /*
+         * Don't update inode if the file type is different
+         */
+        umode = p9mode2unixmode(v9ses, st, &rdev);
+        if ((inode->i_mode & S_IFMT) != (umode & S_IFMT))
+                goto out;
 
         spin_lock(&inode->i_lock);
         /*
@@ -1418,6 +1426,7 @@ int v9fs_refresh_inode(struct p9_fid *fid, struct inode *inode)
         if (v9ses->cache)
                 inode->i_size = i_size;
         spin_unlock(&inode->i_lock);
+out:
         p9stat_free(st);
         kfree(st);
         return 0;
diff --git a/fs/9p/vfs_inode_dotl.c b/fs/9p/vfs_inode_dotl.c
index 0a1723587fa..818bf6f9633 100644
--- a/fs/9p/vfs_inode_dotl.c
+++ b/fs/9p/vfs_inode_dotl.c
@@ -153,7 +153,8 @@ static struct inode *v9fs_qid_iget_dotl(struct super_block *sb,
          * later.
          */
         inode->i_ino = i_ino;
-        retval = v9fs_init_inode(v9ses, inode, st->st_mode);
+        retval = v9fs_init_inode(v9ses, inode,
+                                 st->st_mode, new_decode_dev(st->st_rdev));
         if (retval)
                 goto error;
 
@@ -414,7 +415,7 @@ static int v9fs_vfs_mkdir_dotl(struct inode *dir,
                  * inode with stat. We need to get an inode
                  * so that we can set the acl with dentry
                  */
-                inode = v9fs_get_inode(dir->i_sb, mode);
+                inode = v9fs_get_inode(dir->i_sb, mode, 0);
                 if (IS_ERR(inode)) {
                         err = PTR_ERR(inode);
                         goto error;
@@ -540,6 +541,7 @@ int v9fs_vfs_setattr_dotl(struct dentry *dentry, struct iattr *iattr)
 void
 v9fs_stat2inode_dotl(struct p9_stat_dotl *stat, struct inode *inode)
 {
+        mode_t mode;
         struct v9fs_inode *v9inode = V9FS_I(inode);
 
         if ((stat->st_result_mask & P9_STATS_BASIC) == P9_STATS_BASIC) {
@@ -552,11 +554,10 @@ v9fs_stat2inode_dotl(struct p9_stat_dotl *stat, struct inode *inode)
                 inode->i_uid = stat->st_uid;
                 inode->i_gid = stat->st_gid;
                 inode->i_nlink = stat->st_nlink;
-                inode->i_mode = stat->st_mode;
-                inode->i_rdev = new_decode_dev(stat->st_rdev);
 
-                if ((S_ISBLK(inode->i_mode)) || (S_ISCHR(inode->i_mode)))
-                        init_special_inode(inode, inode->i_mode, inode->i_rdev);
+                mode = stat->st_mode & S_IALLUGO;
+                mode |= inode->i_mode & ~S_IALLUGO;
+                inode->i_mode = mode;
 
                 i_size_write(inode, stat->st_size);
                 inode->i_blocks = stat->st_blocks;
@@ -664,7 +665,7 @@ v9fs_vfs_symlink_dotl(struct inode *dir, struct dentry *dentry,
                 fid = NULL;
         } else {
                 /* Not in cached mode. No need to populate inode with stat */
-                inode = v9fs_get_inode(dir->i_sb, S_IFLNK);
+                inode = v9fs_get_inode(dir->i_sb, S_IFLNK, 0);
                 if (IS_ERR(inode)) {
                         err = PTR_ERR(inode);
                         goto error;
@@ -820,7 +821,7 @@ v9fs_vfs_mknod_dotl(struct inode *dir, struct dentry *dentry, int omode,
                  * Not in cached mode. No need to populate inode with stat.
                  * socket syscall returns a fd, so we need instantiate
                  */
-                inode = v9fs_get_inode(dir->i_sb, mode);
+                inode = v9fs_get_inode(dir->i_sb, mode, rdev);
                 if (IS_ERR(inode)) {
                         err = PTR_ERR(inode);
                         goto error;
@@ -886,6 +887,11 @@ int v9fs_refresh_inode_dotl(struct p9_fid *fid, struct inode *inode)
         st = p9_client_getattr_dotl(fid, P9_STATS_ALL);
         if (IS_ERR(st))
                 return PTR_ERR(st);
+        /*
+         * Don't update inode if the file type is different
+         */
+        if ((inode->i_mode & S_IFMT) != (st->st_mode & S_IFMT))
+                goto out;
 
         spin_lock(&inode->i_lock);
         /*
@@ -897,6 +903,7 @@ int v9fs_refresh_inode_dotl(struct p9_fid *fid, struct inode *inode)
         if (v9ses->cache)
                 inode->i_size = i_size;
         spin_unlock(&inode->i_lock);
+out:
         kfree(st);
         return 0;
 }
diff --git a/fs/9p/vfs_super.c b/fs/9p/vfs_super.c
index feef6cdc1fd..c70251d47ed 100644
--- a/fs/9p/vfs_super.c
+++ b/fs/9p/vfs_super.c
@@ -149,7 +149,7 @@ static struct dentry *v9fs_mount(struct file_system_type *fs_type, int flags,
         else
                 sb->s_d_op = &v9fs_dentry_operations;
 
-        inode = v9fs_get_inode(sb, S_IFDIR | mode);
+        inode = v9fs_get_inode(sb, S_IFDIR | mode, 0);
         if (IS_ERR(inode)) {
                 retval = PTR_ERR(inode);
                 goto release_sb;