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

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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>
This commit is contained in:
Daniel Rosenberg 2016-10-26 16:33:11 -07:00
parent 21fc44e40a
commit 1cbf8e31e3
7 changed files with 34 additions and 15 deletions
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12
fs/attr.c
View file

@ -187,7 +187,7 @@ 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;
@ -262,7 +262,9 @@ 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);
@ -275,4 +277,10 @@ 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);

2
fs/coredump.c
View file

@ -695,7 +695,7 @@ 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;
}

6
fs/inode.c
View file

@ -1715,7 +1715,7 @@ int dentry_needs_remove_privs(struct dentry *dentry)
}
EXPORT_SYMBOL(dentry_needs_remove_privs);
static int __remove_privs(struct dentry *dentry, int kill)
static int __remove_privs(struct vfsmount *mnt, struct dentry *dentry, int kill)
{
struct iattr newattrs;
@ -1724,7 +1724,7 @@ 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);
}
/*
@ -1746,7 +1746,7 @@ 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);

2
fs/namei.c
View file

@ -2760,7 +2760,7 @@ 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);
}

21
fs/open.c
View file

@ -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,
mutex_lock(&dentry->d_inode->i_mutex);
/* Note any delegations or leases have already been broken: */
ret = notify_change(dentry, &newattrs, NULL);
ret = notify_change2(mnt, dentry, &newattrs, NULL);
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)
{
@ -108,7 +113,7 @@ 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);
@ -157,6 +162,7 @@ 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;
@ -173,6 +179,7 @@ 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))
@ -192,7 +199,7 @@ 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);
@ -522,7 +529,7 @@ 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:
mutex_unlock(&inode->i_mutex);
if (delegated_inode) {
@ -602,7 +609,7 @@ retry_deleg:
mutex_lock(&inode->i_mutex);
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);
mutex_unlock(&inode->i_mutex);
if (delegated_inode) {
error = break_deleg_wait(&delegated_inode);

2
fs/utimes.c
View file

@ -104,7 +104,7 @@ static int utimes_common(struct path *path, struct timespec *times)
}
retry_deleg:
mutex_lock(&inode->i_mutex);
error = notify_change(path->dentry, &newattrs, &delegated_inode);
error = notify_change2(path->mnt, path->dentry, &newattrs, &delegated_inode);
mutex_unlock(&inode->i_mutex);
if (delegated_inode) {
error = break_deleg_wait(&delegated_inode);

4
include/linux/fs.h
View file

@ -1661,6 +1661,7 @@ struct inode_operations {
int (*rename2) (struct inode *, struct dentry *,
struct inode *, struct dentry *, unsigned int);
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);
@ -2226,6 +2227,8 @@ 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 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,
@ -2450,6 +2453,7 @@ 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 inode_permission2(struct vfsmount *, struct inode *, int);
extern int __inode_permission(struct inode *, int);