Revert "Revert "ANDROID: vfs: Add setattr2 for filesystems with per mount permissions""

This reverts commit 584c54745dab64b304485ea16e0dff1811e5598a.

Signed-off-by: Amit Pundir <amit.pundir@linaro.org>

7 files changed, 37 insertions, 16 deletions

diff --git a/fs/attr.c b/fs/attr.c
index b4bbdbd4c8ca..b92f2be05a66 100644
--- a/fs/attr.c
+++ b/fs/attr.c
@@ -220,7 +220,7 @@ EXPORT_SYMBOL(setattr_copy);
  * the file open for write, as there can be no conflicting delegation in
  * that case.
  */
-int notify_change(struct dentry * dentry, struct iattr * attr, struct inode **delegated_inode)
+int notify_change2(struct vfsmount *mnt, struct dentry * dentry, struct iattr * attr, struct inode **delegated_inode)
 {
 	struct inode *inode = dentry->d_inode;
 	umode_t mode = inode->i_mode;
@@ -332,7 +332,9 @@ int notify_change(struct dentry * dentry, struct iattr * attr, struct inode **de
 	if (error)
 		return error;
 
-	if (inode->i_op->setattr)
+	if (mnt && inode->i_op->setattr2)
+		error = inode->i_op->setattr2(mnt, dentry, attr);
+	else if (inode->i_op->setattr)
 		error = inode->i_op->setattr(dentry, attr);
 	else
 		error = simple_setattr(dentry, attr);
@@ -345,4 +347,10 @@ int notify_change(struct dentry * dentry, struct iattr * attr, struct inode **de
 
 	return error;
 }
+EXPORT_SYMBOL_GPL(notify_change2);
+
+int notify_change(struct dentry * dentry, struct iattr * attr, struct inode **delegated_inode)
+{
+	return notify_change2(NULL, dentry, attr, delegated_inode);
+}
 EXPORT_SYMBOL(notify_change);
diff --git a/fs/coredump.c b/fs/coredump.c
index 478a0d810136..4944844da983 100644
--- a/fs/coredump.c
+++ b/fs/coredump.c
@@ -777,7 +777,7 @@ void do_coredump(const kernel_siginfo_t *siginfo)
 			goto close_fail;
 		if (!(cprm.file->f_mode & FMODE_CAN_WRITE))
 			goto close_fail;
-		if (do_truncate(cprm.file->f_path.dentry, 0, 0, cprm.file))
+		if (do_truncate2(cprm.file->f_path.mnt, cprm.file->f_path.dentry, 0, 0, cprm.file))
 			goto close_fail;
 	}
 
diff --git a/fs/inode.c b/fs/inode.c
index 93d9252a00ab..10e21db3b0cd 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -1822,7 +1822,7 @@ int dentry_needs_remove_privs(struct dentry *dentry)
 	return mask;
 }
 
-static int __remove_privs(struct dentry *dentry, int kill)
+static int __remove_privs(struct vfsmount *mnt, struct dentry *dentry, int kill)
 {
 	struct iattr newattrs;
 
@@ -1831,7 +1831,7 @@ static int __remove_privs(struct dentry *dentry, int kill)
 	 * Note we call this on write, so notify_change will not
 	 * encounter any conflicting delegations:
 	 */
-	return notify_change(dentry, &newattrs, NULL);
+	return notify_change2(mnt, dentry, &newattrs, NULL);
 }
 
 /*
@@ -1858,7 +1858,7 @@ int file_remove_privs(struct file *file)
 	if (kill < 0)
 		return kill;
 	if (kill)
-		error = __remove_privs(dentry, kill);
+		error = __remove_privs(file->f_path.mnt, dentry, kill);
 	if (!error)
 		inode_has_no_xattr(inode);
 
diff --git a/fs/namei.c b/fs/namei.c
index 196379d18194..41a4dee3e858 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -2968,7 +2968,7 @@ static int handle_truncate(struct file *filp)
 	if (!error)
 		error = security_path_truncate(path);
 	if (!error) {
-		error = do_truncate(path->dentry, 0,
+		error = do_truncate2(path->mnt, path->dentry, 0,
 				    ATTR_MTIME|ATTR_CTIME|ATTR_OPEN,
 				    filp);
 	}
diff --git a/fs/open.c b/fs/open.c
index 719b320ede52..2a2a75a6888f 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -35,8 +35,8 @@
 
 #include "internal.h"
 
-int do_truncate(struct dentry *dentry, loff_t length, unsigned int time_attrs,
-	struct file *filp)
+int do_truncate2(struct vfsmount *mnt, struct dentry *dentry, loff_t length,
+		unsigned int time_attrs, struct file *filp)
 {
 	int ret;
 	struct iattr newattrs;
@@ -61,17 +61,24 @@ int do_truncate(struct dentry *dentry, loff_t length, unsigned int time_attrs,
 
 	inode_lock(dentry->d_inode);
 	/* Note any delegations or leases have already been broken: */
-	ret = notify_change(dentry, &newattrs, NULL);
+	ret = notify_change2(mnt, dentry, &newattrs, NULL);
 	inode_unlock(dentry->d_inode);
 	return ret;
 }
+int do_truncate(struct dentry *dentry, loff_t length, unsigned int time_attrs,
+	struct file *filp)
+{
+	return do_truncate2(NULL, dentry, length, time_attrs, filp);
+}
 
 long vfs_truncate(const struct path *path, loff_t length)
 {
 	struct inode *inode;
+	struct vfsmount *mnt;
 	long error;
 
 	inode = path->dentry->d_inode;
+	mnt = path->mnt;
 
 	/* For directories it's -EISDIR, for other non-regulars - -EINVAL */
 	if (S_ISDIR(inode->i_mode))
@@ -107,7 +114,7 @@ long vfs_truncate(const struct path *path, loff_t length)
 	if (!error)
 		error = security_path_truncate(path);
 	if (!error)
-		error = do_truncate(path->dentry, length, 0, NULL);
+		error = do_truncate2(mnt, path->dentry, length, 0, NULL);
 
 put_write_and_out:
 	put_write_access(inode);
@@ -156,6 +163,7 @@ long do_sys_ftruncate(unsigned int fd, loff_t length, int small)
 {
 	struct inode *inode;
 	struct dentry *dentry;
+	struct vfsmount *mnt;
 	struct fd f;
 	int error;
 
@@ -172,6 +180,7 @@ long do_sys_ftruncate(unsigned int fd, loff_t length, int small)
 		small = 0;
 
 	dentry = f.file->f_path.dentry;
+	mnt = f.file->f_path.mnt;
 	inode = dentry->d_inode;
 	error = -EINVAL;
 	if (!S_ISREG(inode->i_mode) || !(f.file->f_mode & FMODE_WRITE))
@@ -192,7 +201,7 @@ long do_sys_ftruncate(unsigned int fd, loff_t length, int small)
 	if (!error)
 		error = security_path_truncate(&f.file->f_path);
 	if (!error)
-		error = do_truncate(dentry, length, ATTR_MTIME|ATTR_CTIME, f.file);
+		error = do_truncate2(mnt, dentry, length, ATTR_MTIME|ATTR_CTIME, f.file);
 	sb_end_write(inode->i_sb);
 out_putf:
 	fdput(f);
@@ -558,7 +567,7 @@ retry_deleg:
 		goto out_unlock;
 	newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO);
 	newattrs.ia_valid = ATTR_MODE | ATTR_CTIME;
-	error = notify_change(path->dentry, &newattrs, &delegated_inode);
+	error = notify_change2(path->mnt, path->dentry, &newattrs, &delegated_inode);
 out_unlock:
 	inode_unlock(inode);
 	if (delegated_inode) {
@@ -649,7 +658,7 @@ retry_deleg:
 	inode_lock(inode);
 	error = security_path_chown(path, uid, gid);
 	if (!error)
-		error = notify_change(path->dentry, &newattrs, &delegated_inode);
+		error = notify_change2(path->mnt, path->dentry, &newattrs, &delegated_inode);
 	inode_unlock(inode);
 	if (delegated_inode) {
 		error = break_deleg_wait(&delegated_inode);
diff --git a/fs/utimes.c b/fs/utimes.c
index 1d17ce98cb80..534fa3cc517f 100644
--- a/fs/utimes.c
+++ b/fs/utimes.c
@@ -57,7 +57,7 @@ static int utimes_common(const struct path *path, struct timespec64 *times)
 	}
 retry_deleg:
 	inode_lock(inode);
-	error = notify_change(path->dentry, &newattrs, &delegated_inode);
+	error = notify_change2(path->mnt, path->dentry, &newattrs, &delegated_inode);
 	inode_unlock(inode);
 	if (delegated_inode) {
 		error = break_deleg_wait(&delegated_inode);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 234b67cd7ba1..4746526230bb 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1893,7 +1893,8 @@ struct inode_operations {
 	int (*rename) (struct inode *, struct dentry *,
 			struct inode *, struct dentry *, unsigned int);
 	int (*setattr) (struct dentry *, struct iattr *);
-	int (*getattr) (const struct path *, struct kstat *, u32, unsigned int);
+	int (*setattr2) (struct vfsmount *, struct dentry *, struct iattr *);
+        int (*getattr) (const struct path *, struct kstat *, u32, unsigned int);
 	ssize_t (*listxattr) (struct dentry *, char *, size_t);
 	int (*fiemap)(struct inode *, struct fiemap_extent_info *, u64 start,
 		      u64 len);
@@ -2558,6 +2559,8 @@ static_assert(offsetof(struct filename, iname) % sizeof(long) == 0);
 extern long vfs_truncate(const struct path *, loff_t);
 extern int do_truncate(struct dentry *, loff_t start, unsigned int time_attrs,
 		       struct file *filp);
+extern int do_truncate2(struct vfsmount *, struct dentry *, loff_t start,
+			unsigned int time_attrs, struct file *filp);
 extern int vfs_fallocate(struct file *file, int mode, loff_t offset,
 			loff_t len);
 extern long do_sys_open(int dfd, const char __user *filename, int flags,
@@ -2907,6 +2910,7 @@ static inline int bmap(struct inode *inode,  sector_t *block)
 #endif
 
 extern int notify_change(struct dentry *, struct iattr *, struct inode **);
+extern int notify_change2(struct vfsmount *, struct dentry *, struct iattr *, struct inode **);
 extern int inode_permission(struct inode *, int);
 extern int generic_permission(struct inode *, int);
 extern int __check_sticky(struct inode *dir, struct inode *inode);