evie/android_kernel_oneplus_msm8998
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locks: helper functions for delegation breaking

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We'll need the same logic for rename and link.

Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
J. Bruce Fields 2012-08-28 07:50:40 -07:00 • committed by Al Viro
parent b21996e36c
commit 5a14696c17
2 changed files with 40 additions and 12 deletions
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13
fs/namei.c
View file

@ -3650,14 +3650,9 @@ int vfs_unlink(struct inode *dir, struct dentry *dentry, struct inode **delegate
else { else {
error = security_inode_unlink(dir, dentry); error = security_inode_unlink(dir, dentry);
if (!error) { if (!error) {
error = break_deleg(target, O_WRONLY|O_NONBLOCK); error = try_break_deleg(target, delegated_inode);
if (error) { if (error)
if (error == -EWOULDBLOCK && delegated_inode) {
*delegated_inode = target;
ihold(target);
}
goto out; goto out;
}
error = dir->i_op->unlink(dir, dentry); error = dir->i_op->unlink(dir, dentry);
if (!error) if (!error)
dont_mount(dentry); dont_mount(dentry);
@ -3727,9 +3722,7 @@ exit2:
iput(inode); /* truncate the inode here */ iput(inode); /* truncate the inode here */
inode = NULL; inode = NULL;
if (delegated_inode) { if (delegated_inode) {
error = break_deleg(delegated_inode, O_WRONLY); error = break_deleg_wait(&delegated_inode);
iput(delegated_inode);
delegated_inode = NULL;
if (!error) if (!error)
goto retry_deleg; goto retry_deleg;
} }

39
include/linux/fs.h
View file

@ -1905,6 +1905,9 @@ extern bool fs_fully_visible(struct file_system_type *);
extern int current_umask(void); extern int current_umask(void);
extern void ihold(struct inode * inode);
extern void iput(struct inode *);
/* /sys/fs */ /* /sys/fs */
extern struct kobject *fs_kobj; extern struct kobject *fs_kobj;
@ -1972,6 +1975,28 @@ static inline int break_deleg(struct inode *inode, unsigned int mode)
return 0; return 0;
} }
static inline int try_break_deleg(struct inode *inode, struct inode **delegated_inode)
{
int ret;
ret = break_deleg(inode, O_WRONLY|O_NONBLOCK);
if (ret == -EWOULDBLOCK && delegated_inode) {
*delegated_inode = inode;
ihold(inode);
}
return ret;
}
static inline int break_deleg_wait(struct inode **delegated_inode)
{
int ret;
ret = break_deleg(*delegated_inode, O_WRONLY);
iput(*delegated_inode);
*delegated_inode = NULL;
return ret;
}
#else /* !CONFIG_FILE_LOCKING */ #else /* !CONFIG_FILE_LOCKING */
static inline int locks_mandatory_locked(struct inode *inode) static inline int locks_mandatory_locked(struct inode *inode)
{ {
@ -2015,6 +2040,18 @@ static inline int break_deleg(struct inode *inode, unsigned int mode)
{ {
return 0; return 0;
} }
static inline int try_break_deleg(struct inode *inode, struct inode **delegated_inode)
{
return 0;
}
static inline int break_deleg_wait(struct inode **delegated_inode)
{
BUG();
return 0;
}
#endif /* CONFIG_FILE_LOCKING */ #endif /* CONFIG_FILE_LOCKING */
/* fs/open.c */ /* fs/open.c */
@ -2350,8 +2387,6 @@ extern loff_t vfs_llseek(struct file *file, loff_t offset, int whence);
extern int inode_init_always(struct super_block *, struct inode *); extern int inode_init_always(struct super_block *, struct inode *);
extern void inode_init_once(struct inode *); extern void inode_init_once(struct inode *);
extern void address_space_init_once(struct address_space *mapping); extern void address_space_init_once(struct address_space *mapping);
extern void ihold(struct inode * inode);
extern void iput(struct inode *);
extern struct inode * igrab(struct inode *); extern struct inode * igrab(struct inode *);
extern ino_t iunique(struct super_block *, ino_t); extern ino_t iunique(struct super_block *, ino_t);
extern int inode_needs_sync(struct inode *inode); extern int inode_needs_sync(struct inode *inode);