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 66fa6251c398d7584042c7169967f54bfed4278e..64fc5985c598e3bd9b0e07654e6d899de1ea0c97 100644 (file)
--- a/fs/attr.c
+++ b/fs/attr.c
@@ -167,7 +167,7 @@ void setattr_copy(struct inode *inode, const struct iattr *attr)
 }
 EXPORT_SYMBOL(setattr_copy);
 
-int notify_change(struct dentry * dentry, struct iattr * attr)
+int notify_change2(struct vfsmount *mnt, struct dentry * dentry, struct iattr * attr)
 {
        struct inode *inode = dentry->d_inode;
        umode_t mode = inode->i_mode;
@@ -239,7 +239,9 @@ int notify_change(struct dentry * dentry, struct iattr * attr)
        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);
@@ -252,4 +254,10 @@ int notify_change(struct dentry * dentry, struct iattr * attr)
 
        return error;
 }
+EXPORT_SYMBOL(notify_change2);
+
+int notify_change(struct dentry * dentry, struct iattr * attr)
+{
+       return notify_change2(NULL, dentry, attr);
+}
 EXPORT_SYMBOL(notify_change);

diff --git a/fs/coredump.c b/fs/coredump.c
index 1d402ce5b72f63bcbc1c8d58439aa69a0decea05..c0fba3ff9275d225106ed42846be1e65e3a58207 100644 (file)
--- a/fs/coredump.c
+++ b/fs/coredump.c
@@ -644,7 +644,7 @@ void do_coredump(siginfo_t *siginfo)
                        goto close_fail;
                if (!cprm.file->f_op || !cprm.file->f_op->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 ec45268e3dcae555cfd05f45cacd9258e472766a..c1c76f2227c88594255cf303c2d1bc9abc88eb22 100644 (file)
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -1613,12 +1613,12 @@ int should_remove_suid(struct dentry *dentry)
 }
 EXPORT_SYMBOL(should_remove_suid);
 
-static int __remove_suid(struct dentry *dentry, int kill)
+static int __remove_suid(struct vfsmount *mnt, struct dentry *dentry, int kill)
 {
        struct iattr newattrs;
 
        newattrs.ia_valid = ATTR_FORCE | kill;
-       return notify_change(dentry, &newattrs);
+       return notify_change2(mnt, dentry, &newattrs);
 }
 
 int file_remove_suid(struct file *file)
@@ -1641,7 +1641,7 @@ int file_remove_suid(struct file *file)
        if (killpriv)
                error = security_inode_killpriv(dentry);
        if (!error && killsuid)
-               error = __remove_suid(dentry, killsuid);
+               error = __remove_suid(file->f_path.mnt, dentry, killsuid);
        if (!error && (inode->i_sb->s_flags & MS_NOSEC))
                inode->i_flags |= S_NOSEC;
 

diff --git a/fs/open.c b/fs/open.c
index 4198b0616c83ec91d23e0f4e0d19b9915d79de47..142b177d037977d632264fb2d2ec67fc49d345b7 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;
@@ -57,10 +57,15 @@ int do_truncate(struct dentry *dentry, loff_t length, unsigned int time_attrs,
                newattrs.ia_valid |= ret | ATTR_FORCE;
 
        mutex_lock(&dentry->d_inode->i_mutex);
-       ret = notify_change(dentry, &newattrs);
+       ret = notify_change2(mnt, dentry, &newattrs);
        mutex_unlock(&dentry->d_inode->i_mutex);
        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(struct path *path, loff_t length)
 {
@@ -105,7 +110,7 @@ long vfs_truncate(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);
@@ -154,6 +159,7 @@ static 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;
 
@@ -170,6 +176,7 @@ static 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))
@@ -189,7 +196,7 @@ static 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);
@@ -482,7 +489,7 @@ static int chmod_common(struct path *path, umode_t mode)
                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);
+       error = notify_change2(path->mnt, path->dentry, &newattrs);
 out_unlock:
        mutex_unlock(&inode->i_mutex);
        mnt_drop_write(path->mnt);
@@ -556,7 +563,7 @@ static int chown_common(struct path *path, uid_t user, gid_t group)
        mutex_lock(&inode->i_mutex);
        error = security_path_chown(path, uid, gid);
        if (!error)
-               error = notify_change(path->dentry, &newattrs);
+               error = notify_change2(path->mnt, path->dentry, &newattrs);
        mutex_unlock(&inode->i_mutex);
 
        return error;

diff --git a/fs/utimes.c b/fs/utimes.c
index 67250973d966f309ed9921abd6278fb5bdfcf858..7216a079d56908bc75cb7c9b8efa87f8e8201e16 100644 (file)
--- a/fs/utimes.c
+++ b/fs/utimes.c
@@ -102,7 +102,7 @@ static int utimes_common(struct path *path, struct timespec *times)
                }
        }
        mutex_lock(&inode->i_mutex);
-       error = notify_change(path->dentry, &newattrs);
+       error = notify_change2(path->mnt, path->dentry, &newattrs);
        mutex_unlock(&inode->i_mutex);
 
 mnt_drop_write_and_out:

diff --git a/include/linux/fs.h b/include/linux/fs.h
index 6238c7307ecd5d78d1e638ffa89d47b73abf4754..87229a3950f4dccbc72ed3353a25ac7a39d419b7 100644 (file)
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1594,6 +1594,7 @@ struct inode_operations {
        int (*rename) (struct inode *, struct dentry *,
                        struct inode *, struct dentry *);
        int (*setattr) (struct dentry *, struct iattr *);
+       int (*setattr2) (struct vfsmount *, struct dentry *, struct iattr *);
        int (*getattr) (struct vfsmount *mnt, struct dentry *, struct kstat *);
        int (*setxattr) (struct dentry *, const char *,const void *,size_t,int);
        ssize_t (*getxattr) (struct dentry *, const char *, void *, size_t);
@@ -2038,6 +2039,8 @@ struct filename {
 extern long vfs_truncate(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 do_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,
@@ -2247,6 +2250,7 @@ extern int intr_sync(int *);
 extern sector_t bmap(struct inode *, sector_t);
 #endif
 extern int notify_change(struct dentry *, struct iattr *);
+extern int notify_change2(struct vfsmount *, struct dentry *, struct iattr *);
 extern int inode_permission(struct inode *, int);
 extern int inode_permission2(struct vfsmount *, struct inode *, int);
 extern int generic_permission(struct inode *, int);