Commit 790eac56 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 

Pull second set of VFS changes from Al Viro:
 "Assorted f_pos race fixes, making do_splice_direct() safe to call with
  i_mutex on parent, O_TMPFILE support, Jeff's locks.c series,
  ->d_hash/->d_compare calling conventions changes from Linus, misc
  stuff all over the place."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (63 commits)
  Document ->tmpfile()
  ext4: ->tmpfile() support
  vfs: export lseek_execute() to modules
  lseek_execute() doesn't need an inode passed to it
  block_dev: switch to fixed_size_llseek()
  cpqphp_sysfs: switch to fixed_size_llseek()
  tile-srom: switch to fixed_size_llseek()
  proc_powerpc: switch to fixed_size_llseek()
  ubi/cdev: switch to fixed_size_llseek()
  pci/proc: switch to fixed_size_llseek()
  isapnp: switch to fixed_size_llseek()
  lpfc: switch to fixed_size_llseek()
  locks: give the blocked_hash its own spinlock
  locks: add a new "lm_owner_key" lock operation
  locks: turn the blocked_list into a hashtable
  locks: convert fl_link to a hlist_node
  locks: avoid taking global lock if possible when waking up blocked waiters
  locks: protect most of the file_lock handling with i_lock
  locks: encapsulate the fl_link list handling
  locks: make "added" in __posix_lock_file a bool
  ...
parents 0b0585c3 48bde8d3

Documentation/filesystems/Locking

+24 −11
Original line number Original line Diff line number Diff line
@@ -11,10 +11,8 @@ be able to use diff(1). 
prototypes:

prototypes:

	int (*d_revalidate)(struct dentry *, unsigned int);

	int (*d_revalidate)(struct dentry *, unsigned int);

	int (*d_weak_revalidate)(struct dentry *, unsigned int);

	int (*d_weak_revalidate)(struct dentry *, unsigned int);

	int (*d_hash)(const struct dentry *, const struct inode *,

	int (*d_hash)(const struct dentry *, struct qstr *);

			struct qstr *);

	int (*d_compare)(const struct dentry *, const struct dentry *,

	int (*d_compare)(const struct dentry *, const struct inode *,

			const struct dentry *, const struct inode *,

			unsigned int, const char *, const struct qstr *);

			unsigned int, const char *, const struct qstr *);

	int (*d_delete)(struct dentry *);

	int (*d_delete)(struct dentry *);

	void (*d_release)(struct dentry *);

	void (*d_release)(struct dentry *);
@@ -66,6 +64,7 @@ prototypes: 
	int (*atomic_open)(struct inode *, struct dentry *,

	int (*atomic_open)(struct inode *, struct dentry *,

				struct file *, unsigned open_flag,

				struct file *, unsigned open_flag,

				umode_t create_mode, int *opened);

				umode_t create_mode, int *opened);

	int (*tmpfile) (struct inode *, struct dentry *, umode_t);





locking rules:

locking rules:

	all may block

	all may block
@@ -93,6 +92,7 @@ removexattr: yes 
fiemap:		no

fiemap:		no

update_time:	no

update_time:	no

atomic_open:	yes

atomic_open:	yes

tmpfile:	no





	Additionally, ->rmdir(), ->unlink() and ->rename() have ->i_mutex on

	Additionally, ->rmdir(), ->unlink() and ->rename() have ->i_mutex on

victim.

victim.
@@ -344,25 +344,38 @@ prototypes: 








locking rules:

locking rules:

			file_lock_lock	may block

			inode->i_lock	may block

fl_copy_lock:		yes		no

fl_copy_lock:		yes		no

fl_release_private:	maybe		no

fl_release_private:	maybe		no





----------------------- lock_manager_operations ---------------------------

----------------------- lock_manager_operations ---------------------------

prototypes:

prototypes:

	int (*lm_compare_owner)(struct file_lock *, struct file_lock *);

	int (*lm_compare_owner)(struct file_lock *, struct file_lock *);

	unsigned long (*lm_owner_key)(struct file_lock *);

	void (*lm_notify)(struct file_lock *);  /* unblock callback */

	void (*lm_notify)(struct file_lock *);  /* unblock callback */

	int (*lm_grant)(struct file_lock *, struct file_lock *, int);

	int (*lm_grant)(struct file_lock *, struct file_lock *, int);

	void (*lm_break)(struct file_lock *); /* break_lease callback */

	void (*lm_break)(struct file_lock *); /* break_lease callback */

	int (*lm_change)(struct file_lock **, int);

	int (*lm_change)(struct file_lock **, int);





locking rules:

locking rules:

			file_lock_lock	may block



lm_compare_owner:	yes		no

			inode->i_lock	blocked_lock_lock	may block

lm_notify:		yes		no

lm_compare_owner:	yes[1]		maybe			no

lm_grant:		no		no

lm_owner_key		yes[1]		yes			no

lm_break:		yes		no

lm_notify:		yes		yes			no

lm_change		yes		no

lm_grant:		no		no			no

lm_break:		yes		no			no

lm_change		yes		no			no



[1]:	->lm_compare_owner and ->lm_owner_key are generally called with

*an* inode->i_lock held. It may not be the i_lock of the inode

associated with either file_lock argument! This is the case with deadlock

detection, since the code has to chase down the owners of locks that may

be entirely unrelated to the one on which the lock is being acquired.

For deadlock detection however, the blocked_lock_lock is also held. The

fact that these locks are held ensures that the file_locks do not

disappear out from under you while doing the comparison or generating an

owner key.





--------------------------- buffer_head -----------------------------------

--------------------------- buffer_head -----------------------------------

prototypes:

prototypes:

Documentation/filesystems/vfs.txt

+13 −11
Original line number Original line Diff line number Diff line
@@ -360,6 +360,8 @@ struct inode_operations { 
	int (*removexattr) (struct dentry *, const char *);

	int (*removexattr) (struct dentry *, const char *);

	void (*update_time)(struct inode *, struct timespec *, int);

	void (*update_time)(struct inode *, struct timespec *, int);

	int (*atomic_open)(struct inode *, struct dentry *,

	int (*atomic_open)(struct inode *, struct dentry *,

	int (*tmpfile) (struct inode *, struct dentry *, umode_t);

} ____cacheline_aligned;

				struct file *, unsigned open_flag,

				struct file *, unsigned open_flag,

				umode_t create_mode, int *opened);

				umode_t create_mode, int *opened);

};

};
@@ -472,6 +474,9 @@ otherwise noted. 
  	component is negative or needs lookup.  Cached positive dentries are

  	component is negative or needs lookup.  Cached positive dentries are

  	still handled by f_op->open().

  	still handled by f_op->open().





  tmpfile: called in the end of O_TMPFILE open().  Optional, equivalent to

	atomically creating, opening and unlinking a file in given directory.



The Address Space Object

The Address Space Object

========================

========================
@@ -901,10 +906,8 @@ defined: 
struct dentry_operations {

struct dentry_operations {

	int (*d_revalidate)(struct dentry *, unsigned int);

	int (*d_revalidate)(struct dentry *, unsigned int);

	int (*d_weak_revalidate)(struct dentry *, unsigned int);

	int (*d_weak_revalidate)(struct dentry *, unsigned int);

	int (*d_hash)(const struct dentry *, const struct inode *,

	int (*d_hash)(const struct dentry *, struct qstr *);

			struct qstr *);

	int (*d_compare)(const struct dentry *, const struct dentry *,

	int (*d_compare)(const struct dentry *, const struct inode *,

			const struct dentry *, const struct inode *,

			unsigned int, const char *, const struct qstr *);

			unsigned int, const char *, const struct qstr *);

	int (*d_delete)(const struct dentry *);

	int (*d_delete)(const struct dentry *);

	void (*d_release)(struct dentry *);

	void (*d_release)(struct dentry *);
@@ -949,25 +952,24 @@ struct dentry_operations { 




  d_hash: called when the VFS adds a dentry to the hash table. The first

  d_hash: called when the VFS adds a dentry to the hash table. The first

	dentry passed to d_hash is the parent directory that the name is

	dentry passed to d_hash is the parent directory that the name is

	to be hashed into. The inode is the dentry's inode.

	to be hashed into.





	Same locking and synchronisation rules as d_compare regarding

	Same locking and synchronisation rules as d_compare regarding

	what is safe to dereference etc.

	what is safe to dereference etc.





  d_compare: called to compare a dentry name with a given name. The first

  d_compare: called to compare a dentry name with a given name. The first

	dentry is the parent of the dentry to be compared, the second is

	dentry is the parent of the dentry to be compared, the second is

	the parent's inode, then the dentry and inode (may be NULL) of the

	the child dentry. len and name string are properties of the dentry

	child dentry. len and name string are properties of the dentry to be

	to be compared. qstr is the name to compare it with.

	compared. qstr is the name to compare it with.





	Must be constant and idempotent, and should not take locks if

	Must be constant and idempotent, and should not take locks if

	possible, and should not or store into the dentry or inodes.

	possible, and should not or store into the dentry.

	Should not dereference pointers outside the dentry or inodes without

	Should not dereference pointers outside the dentry without

	lots of care (eg.  d_parent, d_inode, d_name should not be used).

	lots of care (eg.  d_parent, d_inode, d_name should not be used).





	However, our vfsmount is pinned, and RCU held, so the dentries and

	However, our vfsmount is pinned, and RCU held, so the dentries and

	inodes won't disappear, neither will our sb or filesystem module.

	inodes won't disappear, neither will our sb or filesystem module.

	->i_sb and ->d_sb may be used.

	->d_sb may be used.





	It is a tricky calling convention because it needs to be called under

	It is a tricky calling convention because it needs to be called under

	"rcu-walk", ie. without any locks or references on things.

	"rcu-walk", ie. without any locks or references on things.

arch/alpha/include/uapi/asm/fcntl.h

+1 −0
Original line number Original line Diff line number Diff line
@@ -32,6 +32,7 @@ 
#define O_SYNC		(__O_SYNC|O_DSYNC)

#define O_SYNC		(__O_SYNC|O_DSYNC)





#define O_PATH		040000000

#define O_PATH		040000000

#define O_TMPFILE	0100000000





#define F_GETLK		7

#define F_GETLK		7

#define F_SETLK		8

#define F_SETLK		8

arch/arc/kernel/troubleshoot.c

+1 −1
Original line number Original line Diff line number Diff line
@@ -101,7 +101,7 @@ static void show_faulting_vma(unsigned long address, char *buf) 
		if (file) {

		if (file) {

			struct path *path = &file->f_path;

			struct path *path = &file->f_path;

			nm = d_path(path, buf, PAGE_SIZE - 1);

			nm = d_path(path, buf, PAGE_SIZE - 1);

			inode = vma->vm_file->f_path.dentry->d_inode;

			inode = file_inode(vma->vm_file);

			dev = inode->i_sb->s_dev;

			dev = inode->i_sb->s_dev;

			ino = inode->i_ino;

			ino = inode->i_ino;

		}

		}

arch/parisc/include/uapi/asm/fcntl.h

+1 −0
Original line number Original line Diff line number Diff line
@@ -20,6 +20,7 @@ 
#define O_INVISIBLE	004000000 /* invisible I/O, for DMAPI/XDSM */

#define O_INVISIBLE	004000000 /* invisible I/O, for DMAPI/XDSM */





#define O_PATH		020000000

#define O_PATH		020000000

#define O_TMPFILE	040000000





#define F_GETLK64	8

#define F_GETLK64	8

#define F_SETLK64	9

#define F_SETLK64	9

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