4 files changed, 33 insertions, 2 deletions

diff --git a/fs/cifs/cifs_fs_sb.h b/fs/cifs/cifs_fs_sb.h
index 4797787c6a4..246a167cb91 100644
--- a/fs/cifs/cifs_fs_sb.h
+++ b/fs/cifs/cifs_fs_sb.h
@@ -18,6 +18,8 @@
 #ifndef _CIFS_FS_SB_H
 #define _CIFS_FS_SB_H
 
+#include <linux/backing-dev.h>
+
 #define CIFS_MOUNT_NO_PERM      1 /* do not do client vfs_perm check */
 #define CIFS_MOUNT_SET_UID      2 /* set current's euid in create etc. */
 #define CIFS_MOUNT_SERVER_INUM  4 /* inode numbers from uniqueid from server  */
@@ -50,5 +52,6 @@ struct cifs_sb_info {
 #ifdef CONFIG_CIFS_DFS_UPCALL
 	char   *mountdata; /* mount options received at mount time */
 #endif
+	struct backing_dev_info bdi;
 };
 #endif				/* _CIFS_FS_SB_H */
diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
index 833166372a0..78c02eb4cb1 100644
--- a/fs/cifs/cifsfs.c
+++ b/fs/cifs/cifsfs.c
@@ -97,6 +97,12 @@ cifs_read_super(struct super_block *sb, void *data,
 	if (cifs_sb == NULL)
 		return -ENOMEM;
 
+	rc = bdi_setup_and_register(&cifs_sb->bdi, "cifs", BDI_CAP_MAP_COPY);
+	if (rc) {
+		kfree(cifs_sb);
+		return rc;
+	}
+
 #ifdef CONFIG_CIFS_DFS_UPCALL
 	/* copy mount params to sb for use in submounts */
 	/* BB: should we move this after the mount so we
@@ -109,6 +115,7 @@ cifs_read_super(struct super_block *sb, void *data,
 		int len = strlen(data);
 		cifs_sb->mountdata = kzalloc(len + 1, GFP_KERNEL);
 		if (cifs_sb->mountdata == NULL) {
+			bdi_destroy(&cifs_sb->bdi);
 			kfree(sb->s_fs_info);
 			sb->s_fs_info = NULL;
 			return -ENOMEM;
@@ -128,6 +135,7 @@ cifs_read_super(struct super_block *sb, void *data,
 
 	sb->s_magic = CIFS_MAGIC_NUMBER;
 	sb->s_op = &cifs_super_ops;
+	sb->s_bdi = &cifs_sb->bdi;
 /*	if (cifs_sb->tcon->ses->server->maxBuf > MAX_CIFS_HDR_SIZE + 512)
 	    sb->s_blocksize =
 		cifs_sb->tcon->ses->server->maxBuf - MAX_CIFS_HDR_SIZE; */
@@ -173,6 +181,7 @@ out_mount_failed:
 		}
 #endif
 		unload_nls(cifs_sb->local_nls);
+		bdi_destroy(&cifs_sb->bdi);
 		kfree(cifs_sb);
 	}
 	return rc;
@@ -204,6 +213,7 @@ cifs_put_super(struct super_block *sb)
 #endif
 
 	unload_nls(cifs_sb->local_nls);
+	bdi_destroy(&cifs_sb->bdi);
 	kfree(cifs_sb);
 
 	unlock_kernel();
diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index 4a99487400f..a88479ceaad 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -507,6 +507,7 @@ struct dfs_info3_param {
 #define CIFS_FATTR_DFS_REFERRAL		0x1
 #define CIFS_FATTR_DELETE_PENDING	0x2
 #define CIFS_FATTR_NEED_REVAL		0x4
+#define CIFS_FATTR_INO_COLLISION	0x8
 
 struct cifs_fattr {
 	u32		cf_flags;
diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c
index b35cb031c20..5b042fc4645 100644
--- a/fs/cifs/inode.c
+++ b/fs/cifs/inode.c
@@ -715,6 +715,16 @@ cifs_find_inode(struct inode *inode, void *opaque)
 	if (CIFS_I(inode)->uniqueid != fattr->cf_uniqueid)
 		return 0;
 
+	/*
+	 * uh oh -- it's a directory. We can't use it since hardlinked dirs are
+	 * verboten. Disable serverino and return it as if it were found, the
+	 * caller can discard it, generate a uniqueid and retry the find
+	 */
+	if (S_ISDIR(inode->i_mode) && !list_empty(&inode->i_dentry)) {
+		fattr->cf_flags |= CIFS_FATTR_INO_COLLISION;
+		cifs_autodisable_serverino(CIFS_SB(inode->i_sb));
+	}
+
 	return 1;
 }
 
@@ -734,15 +744,22 @@ cifs_iget(struct super_block *sb, struct cifs_fattr *fattr)
 	unsigned long hash;
 	struct inode *inode;
 
+retry_iget5_locked:
 	cFYI(1, "looking for uniqueid=%llu", fattr->cf_uniqueid);
 
 	/* hash down to 32-bits on 32-bit arch */
 	hash = cifs_uniqueid_to_ino_t(fattr->cf_uniqueid);
 
 	inode = iget5_locked(sb, hash, cifs_find_inode, cifs_init_inode, fattr);
-
-	/* we have fattrs in hand, update the inode */
 	if (inode) {
+		/* was there a problematic inode number collision? */
+		if (fattr->cf_flags & CIFS_FATTR_INO_COLLISION) {
+			iput(inode);
+			fattr->cf_uniqueid = iunique(sb, ROOT_I);
+			fattr->cf_flags &= ~CIFS_FATTR_INO_COLLISION;
+			goto retry_iget5_locked;
+		}
+
 		cifs_fattr_to_inode(inode, fattr);
 		if (sb->s_flags & MS_NOATIME)
 			inode->i_flags |= S_NOATIME | S_NOCMTIME;