From 4787d45fa76b97e224a8299086bb5fb496275796 Mon Sep 17 00:00:00 2001
From: Al Viro <viro@zeniv.linux.org.uk>
Date: Wed, 2 Mar 2011 09:38:45 -0500
Subject: [PATCH 1/8] sysv: i_nlink races in rename()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 fs/sysv/namei.c | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/fs/sysv/namei.c b/fs/sysv/namei.c
index b427b1208c26..e474fbcf8bde 100644
--- a/fs/sysv/namei.c
+++ b/fs/sysv/namei.c
@@ -245,7 +245,6 @@ static int sysv_rename(struct inode * old_dir, struct dentry * old_dentry,
 		new_de = sysv_find_entry(new_dentry, &new_page);
 		if (!new_de)
 			goto out_dir;
-		inode_inc_link_count(old_inode);
 		sysv_set_link(new_de, new_page, old_inode);
 		new_inode->i_ctime = CURRENT_TIME_SEC;
 		if (dir_de)
@@ -257,18 +256,15 @@ static int sysv_rename(struct inode * old_dir, struct dentry * old_dentry,
 			if (new_dir->i_nlink >= SYSV_SB(new_dir->i_sb)->s_link_max)
 				goto out_dir;
 		}
-		inode_inc_link_count(old_inode);
 		err = sysv_add_link(new_dentry, old_inode);
-		if (err) {
-			inode_dec_link_count(old_inode);
+		if (err)
 			goto out_dir;
-		}
 		if (dir_de)
 			inode_inc_link_count(new_dir);
 	}
 
 	sysv_delete_entry(old_de, old_page);
-	inode_dec_link_count(old_inode);
+	mark_inode_dirty(old_inode);
 
 	if (dir_de) {
 		sysv_set_link(dir_de, dir_page, new_dir);

From 37750cdda36721fa7fa816f5f58258d2c013b248 Mon Sep 17 00:00:00 2001
From: Al Viro <viro@zeniv.linux.org.uk>
Date: Wed, 2 Mar 2011 09:40:21 -0500
Subject: [PATCH 2/8] ufs: i_nlink races in rename()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 fs/ufs/namei.c | 9 ++-------
 1 file changed, 2 insertions(+), 7 deletions(-)

diff --git a/fs/ufs/namei.c b/fs/ufs/namei.c
index 12f39b9e4437..d6f681535eb8 100644
--- a/fs/ufs/namei.c
+++ b/fs/ufs/namei.c
@@ -306,7 +306,6 @@ static int ufs_rename(struct inode *old_dir, struct dentry *old_dentry,
 		new_de = ufs_find_entry(new_dir, &new_dentry->d_name, &new_page);
 		if (!new_de)
 			goto out_dir;
-		inode_inc_link_count(old_inode);
 		ufs_set_link(new_dir, new_de, new_page, old_inode);
 		new_inode->i_ctime = CURRENT_TIME_SEC;
 		if (dir_de)
@@ -318,12 +317,9 @@ static int ufs_rename(struct inode *old_dir, struct dentry *old_dentry,
 			if (new_dir->i_nlink >= UFS_LINK_MAX)
 				goto out_dir;
 		}
-		inode_inc_link_count(old_inode);
 		err = ufs_add_link(new_dentry, old_inode);
-		if (err) {
-			inode_dec_link_count(old_inode);
+		if (err)
 			goto out_dir;
-		}
 		if (dir_de)
 			inode_inc_link_count(new_dir);
 	}
@@ -331,12 +327,11 @@ static int ufs_rename(struct inode *old_dir, struct dentry *old_dentry,
 	/*
 	 * Like most other Unix systems, set the ctime for inodes on a
  	 * rename.
-	 * inode_dec_link_count() will mark the inode dirty.
 	 */
 	old_inode->i_ctime = CURRENT_TIME_SEC;
 
 	ufs_delete_entry(old_dir, old_de, old_page);
-	inode_dec_link_count(old_inode);
+	mark_inode_dirty(old_inode);
 
 	if (dir_de) {
 		ufs_set_link(old_inode, dir_de, dir_page, new_dir);

From 6f88049caf56022c773272e03ddfa8cf79867059 Mon Sep 17 00:00:00 2001
From: Al Viro <viro@zeniv.linux.org.uk>
Date: Wed, 2 Mar 2011 09:41:38 -0500
Subject: [PATCH 3/8] minix: i_nlink races in rename()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 fs/minix/namei.c | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/fs/minix/namei.c b/fs/minix/namei.c
index ce7337ddfdbf..6e6777f1b4b2 100644
--- a/fs/minix/namei.c
+++ b/fs/minix/namei.c
@@ -213,7 +213,6 @@ static int minix_rename(struct inode * old_dir, struct dentry *old_dentry,
 		new_de = minix_find_entry(new_dentry, &new_page);
 		if (!new_de)
 			goto out_dir;
-		inode_inc_link_count(old_inode);
 		minix_set_link(new_de, new_page, old_inode);
 		new_inode->i_ctime = CURRENT_TIME_SEC;
 		if (dir_de)
@@ -225,18 +224,15 @@ static int minix_rename(struct inode * old_dir, struct dentry *old_dentry,
 			if (new_dir->i_nlink >= info->s_link_max)
 				goto out_dir;
 		}
-		inode_inc_link_count(old_inode);
 		err = minix_add_link(new_dentry, old_inode);
-		if (err) {
-			inode_dec_link_count(old_inode);
+		if (err)
 			goto out_dir;
-		}
 		if (dir_de)
 			inode_inc_link_count(new_dir);
 	}
 
 	minix_delete_entry(old_de, old_page);
-	inode_dec_link_count(old_inode);
+	mark_inode_dirty(old_inode);
 
 	if (dir_de) {
 		minix_set_link(dir_de, dir_page, new_dir);

From 30eb43d31478f0fca28423623f3ec6af13f845fa Mon Sep 17 00:00:00 2001
From: Al Viro <viro@zeniv.linux.org.uk>
Date: Wed, 2 Mar 2011 12:01:13 -0500
Subject: [PATCH 4/8] nilfs2: i_nlink races in rename()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 fs/nilfs2/namei.c | 8 +-------
 1 file changed, 1 insertion(+), 7 deletions(-)

diff --git a/fs/nilfs2/namei.c b/fs/nilfs2/namei.c
index 98034271cd02..161791d26458 100644
--- a/fs/nilfs2/namei.c
+++ b/fs/nilfs2/namei.c
@@ -397,7 +397,6 @@ static int nilfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 		new_de = nilfs_find_entry(new_dir, &new_dentry->d_name, &new_page);
 		if (!new_de)
 			goto out_dir;
-		inc_nlink(old_inode);
 		nilfs_set_link(new_dir, new_de, new_page, old_inode);
 		nilfs_mark_inode_dirty(new_dir);
 		new_inode->i_ctime = CURRENT_TIME;
@@ -411,13 +410,9 @@ static int nilfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 			if (new_dir->i_nlink >= NILFS_LINK_MAX)
 				goto out_dir;
 		}
-		inc_nlink(old_inode);
 		err = nilfs_add_link(new_dentry, old_inode);
-		if (err) {
-			drop_nlink(old_inode);
-			nilfs_mark_inode_dirty(old_inode);
+		if (err)
 			goto out_dir;
-		}
 		if (dir_de) {
 			inc_nlink(new_dir);
 			nilfs_mark_inode_dirty(new_dir);
@@ -431,7 +426,6 @@ static int nilfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 	old_inode->i_ctime = CURRENT_TIME;
 
 	nilfs_delete_entry(old_de, old_page);
-	drop_nlink(old_inode);
 
 	if (dir_de) {
 		nilfs_set_link(old_inode, dir_de, dir_page, new_dir);

From babfe56046885749b6a90a3c4409219a1f16cf48 Mon Sep 17 00:00:00 2001
From: Al Viro <viro@zeniv.linux.org.uk>
Date: Wed, 2 Mar 2011 16:42:38 -0500
Subject: [PATCH 5/8] exofs: i_nlink races in rename()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 fs/exofs/namei.c | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/fs/exofs/namei.c b/fs/exofs/namei.c
index 264e95d02830..4d70db110cfc 100644
--- a/fs/exofs/namei.c
+++ b/fs/exofs/namei.c
@@ -272,7 +272,6 @@ static int exofs_rename(struct inode *old_dir, struct dentry *old_dentry,
 		new_de = exofs_find_entry(new_dir, new_dentry, &new_page);
 		if (!new_de)
 			goto out_dir;
-		inode_inc_link_count(old_inode);
 		err = exofs_set_link(new_dir, new_de, new_page, old_inode);
 		new_inode->i_ctime = CURRENT_TIME;
 		if (dir_de)
@@ -286,12 +285,9 @@ static int exofs_rename(struct inode *old_dir, struct dentry *old_dentry,
 			if (new_dir->i_nlink >= EXOFS_LINK_MAX)
 				goto out_dir;
 		}
-		inode_inc_link_count(old_inode);
 		err = exofs_add_link(new_dentry, old_inode);
-		if (err) {
-			inode_dec_link_count(old_inode);
+		if (err)
 			goto out_dir;
-		}
 		if (dir_de)
 			inode_inc_link_count(new_dir);
 	}
@@ -299,7 +295,7 @@ static int exofs_rename(struct inode *old_dir, struct dentry *old_dentry,
 	old_inode->i_ctime = CURRENT_TIME;
 
 	exofs_delete_entry(old_de, old_page);
-	inode_dec_link_count(old_inode);
+	mark_inode_dirty(old_inode);
 
 	if (dir_de) {
 		err = exofs_set_link(old_inode, dir_de, dir_page, new_dir);

From 99890a3be1ee67346300f1e0a873006588760f2a Mon Sep 17 00:00:00 2001
From: Al Viro <viro@zeniv.linux.org.uk>
Date: Wed, 2 Mar 2011 09:35:13 -0500
Subject: [PATCH 6/8] fix reiserfs mkdir() breakage

if directory has so many subdirectories that its link count is set
to 1 (i.e. "can't tell accurately") and reiserfs_new_inode() fails,
we shouldn't decrement the parent's link count in cleanup path;
that's what DEC_DIR_INODE_NLINK() is for.  As it is, we end up
with parent suddenly getting zero i_nlink, with very unpleasant
effects.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 fs/reiserfs/namei.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/reiserfs/namei.c b/fs/reiserfs/namei.c
index ba5f51ec3458..68fdf45cc6c9 100644
--- a/fs/reiserfs/namei.c
+++ b/fs/reiserfs/namei.c
@@ -771,7 +771,7 @@ static int reiserfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
 					EMPTY_DIR_SIZE_V1 : EMPTY_DIR_SIZE,
 					dentry, inode, &security);
 	if (retval) {
-		dir->i_nlink--;
+		DEC_DIR_INODE_NLINK(dir)
 		goto out_failed;
 	}
 

From 810c1b2e48d32a8605928c3609262d94853c3a76 Mon Sep 17 00:00:00 2001
From: Al Viro <viro@zeniv.linux.org.uk>
Date: Wed, 2 Mar 2011 10:15:26 -0500
Subject: [PATCH 7/8] udf: fix i_nlink limit

(256 << sizeof(x)) - 1 is not the maximal possible value of x...
In reality, the maximal allowed value for UDF FileLinkCount is
65535.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 fs/udf/namei.c | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/fs/udf/namei.c b/fs/udf/namei.c
index 2be0f9eb86d2..b7c338d5e9df 100644
--- a/fs/udf/namei.c
+++ b/fs/udf/namei.c
@@ -32,6 +32,8 @@
 #include <linux/crc-itu-t.h>
 #include <linux/exportfs.h>
 
+enum { UDF_MAX_LINKS = 0xffff };
+
 static inline int udf_match(int len1, const unsigned char *name1, int len2,
 			    const unsigned char *name2)
 {
@@ -650,7 +652,7 @@ static int udf_mkdir(struct inode *dir, struct dentry *dentry, int mode)
 	struct udf_inode_info *iinfo;
 
 	err = -EMLINK;
-	if (dir->i_nlink >= (256 << sizeof(dir->i_nlink)) - 1)
+	if (dir->i_nlink >= UDF_MAX_LINKS)
 		goto out;
 
 	err = -EIO;
@@ -1034,9 +1036,8 @@ static int udf_link(struct dentry *old_dentry, struct inode *dir,
 	struct fileIdentDesc cfi, *fi;
 	int err;
 
-	if (inode->i_nlink >= (256 << sizeof(inode->i_nlink)) - 1) {
+	if (inode->i_nlink >= UDF_MAX_LINKS)
 		return -EMLINK;
-	}
 
 	fi = udf_add_entry(dir, dentry, &fibh, &cfi, &err);
 	if (!fi) {
@@ -1131,9 +1132,7 @@ static int udf_rename(struct inode *old_dir, struct dentry *old_dentry,
 			goto end_rename;
 
 		retval = -EMLINK;
-		if (!new_inode &&
-			new_dir->i_nlink >=
-				(256 << sizeof(new_dir->i_nlink)) - 1)
+		if (!new_inode && new_dir->i_nlink >= UDF_MAX_LINKS)
 			goto end_rename;
 	}
 	if (!nfi) {

From 69102e9b4b61f56a26717659ec2e572a6b18458d Mon Sep 17 00:00:00 2001
From: Al Viro <viro@zeniv.linux.org.uk>
Date: Wed, 2 Mar 2011 23:46:51 -0500
Subject: [PATCH 8/8] hfs: fix rename() over non-empty directory

merge hfs_unlink() and hfs_rmdir(), while we are at it.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 fs/hfs/dir.c | 52 ++++++++++++++--------------------------------------
 1 file changed, 14 insertions(+), 38 deletions(-)

diff --git a/fs/hfs/dir.c b/fs/hfs/dir.c
index afa66aaa2237..b4d70b13be92 100644
--- a/fs/hfs/dir.c
+++ b/fs/hfs/dir.c
@@ -238,46 +238,22 @@ static int hfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
 }
 
 /*
- * hfs_unlink()
+ * hfs_remove()
  *
- * This is the unlink() entry in the inode_operations structure for
- * regular HFS directories.  The purpose is to delete an existing
- * file, given the inode for the parent directory and the name
- * (and its length) of the existing file.
+ * This serves as both unlink() and rmdir() in the inode_operations
+ * structure for regular HFS directories.  The purpose is to delete
+ * an existing child, given the inode for the parent directory and
+ * the name (and its length) of the existing directory.
+ *
+ * HFS does not have hardlinks, so both rmdir and unlink set the
+ * link count to 0.  The only difference is the emptiness check.
  */
-static int hfs_unlink(struct inode *dir, struct dentry *dentry)
+static int hfs_remove(struct inode *dir, struct dentry *dentry)
 {
-	struct inode *inode;
+	struct inode *inode = dentry->d_inode;
 	int res;
 
-	inode = dentry->d_inode;
-	res = hfs_cat_delete(inode->i_ino, dir, &dentry->d_name);
-	if (res)
-		return res;
-
-	drop_nlink(inode);
-	hfs_delete_inode(inode);
-	inode->i_ctime = CURRENT_TIME_SEC;
-	mark_inode_dirty(inode);
-
-	return res;
-}
-
-/*
- * hfs_rmdir()
- *
- * This is the rmdir() entry in the inode_operations structure for
- * regular HFS directories.  The purpose is to delete an existing
- * directory, given the inode for the parent directory and the name
- * (and its length) of the existing directory.
- */
-static int hfs_rmdir(struct inode *dir, struct dentry *dentry)
-{
-	struct inode *inode;
-	int res;
-
-	inode = dentry->d_inode;
-	if (inode->i_size != 2)
+	if (S_ISDIR(inode->i_mode) && inode->i_size != 2)
 		return -ENOTEMPTY;
 	res = hfs_cat_delete(inode->i_ino, dir, &dentry->d_name);
 	if (res)
@@ -307,7 +283,7 @@ static int hfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 
 	/* Unlink destination if it already exists */
 	if (new_dentry->d_inode) {
-		res = hfs_unlink(new_dir, new_dentry);
+		res = hfs_remove(new_dir, new_dentry);
 		if (res)
 			return res;
 	}
@@ -332,9 +308,9 @@ const struct file_operations hfs_dir_operations = {
 const struct inode_operations hfs_dir_inode_operations = {
 	.create		= hfs_create,
 	.lookup		= hfs_lookup,
-	.unlink		= hfs_unlink,
+	.unlink		= hfs_remove,
 	.mkdir		= hfs_mkdir,
-	.rmdir		= hfs_rmdir,
+	.rmdir		= hfs_remove,
 	.rename		= hfs_rename,
 	.setattr	= hfs_inode_setattr,
 };