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

This allows filesystems to use their mount private data to
influence the permssions they use in setattr2. It has
been separated into a new call to avoid disrupting current
setattr users.

Change-Id: I19959038309284448f1b7f232d579674ef546385
Signed-off-by: Daniel Rosenberg <drosen@google.com>

diff --git a/fs/attr.c b/fs/attr.c
index e3d53bf..60589ac 100644 (file)
--- a/fs/attr.c
+++ b/fs/attr.c
@@ -222,7 +222,7 @@ 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;
@@ -329,7 +329,9 @@ 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);
@@ -342,4 +344,10 @@ int notify_change(struct dentry * dentry, struct iattr * attr, struct inode **de
 
        return error;
 }
+EXPORT_SYMBOL(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 1e2c87a..d9b3ba0 100644 (file)
--- a/fs/coredump.c
+++ b/fs/coredump.c
@@ -742,7 +742,7 @@ void do_coredump(const 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 8c86c80..cb767b7 100644 (file)
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -1787,7 +1787,7 @@ 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;
 
@@ -1796,7 +1796,7 @@ 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);
 }
 
 /*
@@ -1818,7 +1818,7 @@ 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 734cef5..265a914 100644 (file)
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -2986,7 +2986,7 @@ 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 d0e955b..1976c5f 100644 (file)
--- a/fs/open.c
+++ b/fs/open.c
@@ -34,8 +34,8 @@
 
 #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;
@@ -60,10 +60,15 @@ 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)
 {
@@ -117,7 +122,7 @@ 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(upperdentry->d_inode);
@@ -166,6 +171,7 @@ 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;
 
@@ -182,6 +188,7 @@ 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))
@@ -202,7 +209,7 @@ 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);
@@ -549,7 +556,7 @@ 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) {
@@ -640,7 +647,7 @@ 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 69d4b6b..1039ef7 100644 (file)
--- a/fs/utimes.c
+++ b/fs/utimes.c
@@ -88,7 +88,7 @@ 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 08e951c..162c7b9 100644 (file)
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1769,7 +1769,8 @@ 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);
@@ -2418,6 +2419,8 @@ struct filename {
 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,
@@ -2729,6 +2732,7 @@ extern void emergency_remount(void);
 extern sector_t bmap(struct inode *, sector_t);
 #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);