diff options
Diffstat (limited to 'fs/xfs')
| -rw-r--r-- | fs/xfs/xfs_inode.c | 128 | ||||
| -rw-r--r-- | fs/xfs/xfs_inode.h | 29 | ||||
| -rw-r--r-- | fs/xfs/xfs_super.c | 2 |
3 files changed, 121 insertions, 38 deletions
diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c index daafa1f6d260..ac24818f7b2d 100644 --- a/fs/xfs/xfs_inode.c +++ b/fs/xfs/xfs_inode.c @@ -117,24 +117,34 @@ xfs_ilock_attr_map_shared( } /* - * The xfs inode contains 2 locks: a multi-reader lock called the - * i_iolock and a multi-reader lock called the i_lock. This routine - * allows either or both of the locks to be obtained. + * The xfs inode contains 3 multi-reader locks: the i_iolock the i_mmap_lock and + * the i_lock. This routine allows various combinations of the locks to be + * obtained. * - * The 2 locks should always be ordered so that the IO lock is - * obtained first in order to prevent deadlock. + * The 3 locks should always be ordered so that the IO lock is obtained first, + * the mmap lock second and the ilock last in order to prevent deadlock. * - * ip -- the inode being locked - * lock_flags -- this parameter indicates the inode's locks - * to be locked. It can be: - * XFS_IOLOCK_SHARED, - * XFS_IOLOCK_EXCL, - * XFS_ILOCK_SHARED, - * XFS_ILOCK_EXCL, - * XFS_IOLOCK_SHARED | XFS_ILOCK_SHARED, - * XFS_IOLOCK_SHARED | XFS_ILOCK_EXCL, - * XFS_IOLOCK_EXCL | XFS_ILOCK_SHARED, - * XFS_IOLOCK_EXCL | XFS_ILOCK_EXCL + * Basic locking order: + * + * i_iolock -> i_mmap_lock -> page_lock -> i_ilock + * + * mmap_sem locking order: + * + * i_iolock -> page lock -> mmap_sem + * mmap_sem -> i_mmap_lock -> page_lock + * + * The difference in mmap_sem locking order mean that we cannot hold the + * i_mmap_lock over syscall based read(2)/write(2) based IO. These IO paths can + * fault in pages during copy in/out (for buffered IO) or require the mmap_sem + * in get_user_pages() to map the user pages into the kernel address space for + * direct IO. Similarly the i_iolock cannot be taken inside a page fault because + * page faults already hold the mmap_sem. + * + * Hence to serialise fully against both syscall and mmap based IO, we need to + * take both the i_iolock and the i_mmap_lock. These locks should *only* be both + * taken in places where we need to invalidate the page cache in a race + * free manner (e.g. truncate, hole punch and other extent manipulation + * functions). */ void xfs_ilock( @@ -150,6 +160,8 @@ xfs_ilock( */ ASSERT((lock_flags & (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL)) != (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL)); + ASSERT((lock_flags & (XFS_MMAPLOCK_SHARED | XFS_MMAPLOCK_EXCL)) != + (XFS_MMAPLOCK_SHARED | XFS_MMAPLOCK_EXCL)); ASSERT((lock_flags & (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL)) != (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL)); ASSERT((lock_flags & ~(XFS_LOCK_MASK | XFS_LOCK_DEP_MASK)) == 0); @@ -159,6 +171,11 @@ xfs_ilock( else if (lock_flags & XFS_IOLOCK_SHARED) mraccess_nested(&ip->i_iolock, XFS_IOLOCK_DEP(lock_flags)); + if (lock_flags & XFS_MMAPLOCK_EXCL) + mrupdate_nested(&ip->i_mmaplock, XFS_MMAPLOCK_DEP(lock_flags)); + else if (lock_flags & XFS_MMAPLOCK_SHARED) + mraccess_nested(&ip->i_mmaplock, XFS_MMAPLOCK_DEP(lock_flags)); + if (lock_flags & XFS_ILOCK_EXCL) mrupdate_nested(&ip->i_lock, XFS_ILOCK_DEP(lock_flags)); else if (lock_flags & XFS_ILOCK_SHARED) @@ -191,6 +208,8 @@ xfs_ilock_nowait( */ ASSERT((lock_flags & (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL)) != (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL)); + ASSERT((lock_flags & (XFS_MMAPLOCK_SHARED | XFS_MMAPLOCK_EXCL)) != + (XFS_MMAPLOCK_SHARED | XFS_MMAPLOCK_EXCL)); ASSERT((lock_flags & (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL)) != (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL)); ASSERT((lock_flags & ~(XFS_LOCK_MASK | XFS_LOCK_DEP_MASK)) == 0); @@ -202,21 +221,35 @@ xfs_ilock_nowait( if (!mrtryaccess(&ip->i_iolock)) goto out; } + + if (lock_flags & XFS_MMAPLOCK_EXCL) { + if (!mrtryupdate(&ip->i_mmaplock)) + goto out_undo_iolock; + } else if (lock_flags & XFS_MMAPLOCK_SHARED) { + if (!mrtryaccess(&ip->i_mmaplock)) + goto out_undo_iolock; + } + if (lock_flags & XFS_ILOCK_EXCL) { if (!mrtryupdate(&ip->i_lock)) - goto out_undo_iolock; + goto out_undo_mmaplock; } else if (lock_flags & XFS_ILOCK_SHARED) { if (!mrtryaccess(&ip->i_lock)) - goto out_undo_iolock; + goto out_undo_mmaplock; } return 1; - out_undo_iolock: +out_undo_mmaplock: + if (lock_flags & XFS_MMAPLOCK_EXCL) + mrunlock_excl(&ip->i_mmaplock); + else if (lock_flags & XFS_MMAPLOCK_SHARED) + mrunlock_shared(&ip->i_mmaplock); +out_undo_iolock: if (lock_flags & XFS_IOLOCK_EXCL) mrunlock_excl(&ip->i_iolock); else if (lock_flags & XFS_IOLOCK_SHARED) mrunlock_shared(&ip->i_iolock); - out: +out: return 0; } @@ -244,6 +277,8 @@ xfs_iunlock( */ ASSERT((lock_flags & (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL)) != (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL)); + ASSERT((lock_flags & (XFS_MMAPLOCK_SHARED | XFS_MMAPLOCK_EXCL)) != + (XFS_MMAPLOCK_SHARED | XFS_MMAPLOCK_EXCL)); ASSERT((lock_flags & (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL)) != (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL)); ASSERT((lock_flags & ~(XFS_LOCK_MASK | XFS_LOCK_DEP_MASK)) == 0); @@ -254,6 +289,11 @@ xfs_iunlock( else if (lock_flags & XFS_IOLOCK_SHARED) mrunlock_shared(&ip->i_iolock); + if (lock_flags & XFS_MMAPLOCK_EXCL) + mrunlock_excl(&ip->i_mmaplock); + else if (lock_flags & XFS_MMAPLOCK_SHARED) + mrunlock_shared(&ip->i_mmaplock); + if (lock_flags & XFS_ILOCK_EXCL) mrunlock_excl(&ip->i_lock); else if (lock_flags & XFS_ILOCK_SHARED) @@ -271,11 +311,14 @@ xfs_ilock_demote( xfs_inode_t *ip, uint lock_flags) { - ASSERT(lock_flags & (XFS_IOLOCK_EXCL|XFS_ILOCK_EXCL)); - ASSERT((lock_flags & ~(XFS_IOLOCK_EXCL|XFS_ILOCK_EXCL)) == 0); + ASSERT(lock_flags & (XFS_IOLOCK_EXCL|XFS_MMAPLOCK_EXCL|XFS_ILOCK_EXCL)); + ASSERT((lock_flags & + ~(XFS_IOLOCK_EXCL|XFS_MMAPLOCK_EXCL|XFS_ILOCK_EXCL)) == 0); if (lock_flags & XFS_ILOCK_EXCL) mrdemote(&ip->i_lock); + if (lock_flags & XFS_MMAPLOCK_EXCL) + mrdemote(&ip->i_mmaplock); if (lock_flags & XFS_IOLOCK_EXCL) mrdemote(&ip->i_iolock); @@ -294,6 +337,12 @@ xfs_isilocked( return rwsem_is_locked(&ip->i_lock.mr_lock); } + if (lock_flags & (XFS_MMAPLOCK_EXCL|XFS_MMAPLOCK_SHARED)) { + if (!(lock_flags & XFS_MMAPLOCK_SHARED)) + return !!ip->i_mmaplock.mr_writer; + return rwsem_is_locked(&ip->i_mmaplock.mr_lock); + } + if (lock_flags & (XFS_IOLOCK_EXCL|XFS_IOLOCK_SHARED)) { if (!(lock_flags & XFS_IOLOCK_SHARED)) return !!ip->i_iolock.mr_writer; @@ -314,14 +363,27 @@ int xfs_lock_delays; #endif /* - * Bump the subclass so xfs_lock_inodes() acquires each lock with - * a different value + * Bump the subclass so xfs_lock_inodes() acquires each lock with a different + * value. This shouldn't be called for page fault locking, but we also need to + * ensure we don't overrun the number of lockdep subclasses for the iolock or + * mmaplock as that is limited to 12 by the mmap lock lockdep annotations. */ static inline int xfs_lock_inumorder(int lock_mode, int subclass) { - if (lock_mode & (XFS_IOLOCK_SHARED|XFS_IOLOCK_EXCL)) + if (lock_mode & (XFS_IOLOCK_SHARED|XFS_IOLOCK_EXCL)) { + ASSERT(subclass + XFS_LOCK_INUMORDER < + (1 << (XFS_MMAPLOCK_SHIFT - XFS_IOLOCK_SHIFT))); lock_mode |= (subclass + XFS_LOCK_INUMORDER) << XFS_IOLOCK_SHIFT; + } + + if (lock_mode & (XFS_MMAPLOCK_SHARED|XFS_MMAPLOCK_EXCL)) { + ASSERT(subclass + XFS_LOCK_INUMORDER < + (1 << (XFS_ILOCK_SHIFT - XFS_MMAPLOCK_SHIFT))); + lock_mode |= (subclass + XFS_LOCK_INUMORDER) << + XFS_MMAPLOCK_SHIFT; + } + if (lock_mode & (XFS_ILOCK_SHARED|XFS_ILOCK_EXCL)) lock_mode |= (subclass + XFS_LOCK_INUMORDER) << XFS_ILOCK_SHIFT; @@ -440,10 +502,10 @@ again: } /* - * xfs_lock_two_inodes() can only be used to lock one type of lock - * at a time - the iolock or the ilock, but not both at once. If - * we lock both at once, lockdep will report false positives saying - * we have violated locking orders. + * xfs_lock_two_inodes() can only be used to lock one type of lock at a time - + * the iolock, the mmaplock or the ilock, but not more than one at a time. If we + * lock more than one at a time, lockdep will report false positives saying we + * have violated locking orders. */ void xfs_lock_two_inodes( @@ -455,8 +517,12 @@ xfs_lock_two_inodes( int attempts = 0; xfs_log_item_t *lp; - if (lock_mode & (XFS_IOLOCK_SHARED|XFS_IOLOCK_EXCL)) - ASSERT((lock_mode & (XFS_ILOCK_SHARED|XFS_ILOCK_EXCL)) == 0); + if (lock_mode & (XFS_IOLOCK_SHARED|XFS_IOLOCK_EXCL)) { + ASSERT(!(lock_mode & (XFS_MMAPLOCK_SHARED|XFS_MMAPLOCK_EXCL))); + ASSERT(!(lock_mode & (XFS_ILOCK_SHARED|XFS_ILOCK_EXCL))); + } else if (lock_mode & (XFS_MMAPLOCK_SHARED|XFS_MMAPLOCK_EXCL)) + ASSERT(!(lock_mode & (XFS_ILOCK_SHARED|XFS_ILOCK_EXCL))); + ASSERT(ip0->i_ino != ip1->i_ino); if (ip0->i_ino > ip1->i_ino) { diff --git a/fs/xfs/xfs_inode.h b/fs/xfs/xfs_inode.h index 86cd6b39bed7..f65ab8176c2f 100644 --- a/fs/xfs/xfs_inode.h +++ b/fs/xfs/xfs_inode.h @@ -56,6 +56,7 @@ typedef struct xfs_inode { struct xfs_inode_log_item *i_itemp; /* logging information */ mrlock_t i_lock; /* inode lock */ mrlock_t i_iolock; /* inode IO lock */ + mrlock_t i_mmaplock; /* inode mmap IO lock */ atomic_t i_pincount; /* inode pin count */ spinlock_t i_flags_lock; /* inode i_flags lock */ /* Miscellaneous state. */ @@ -263,15 +264,20 @@ static inline int xfs_isiflocked(struct xfs_inode *ip) #define XFS_IOLOCK_SHARED (1<<1) #define XFS_ILOCK_EXCL (1<<2) #define XFS_ILOCK_SHARED (1<<3) +#define XFS_MMAPLOCK_EXCL (1<<4) +#define XFS_MMAPLOCK_SHARED (1<<5) #define XFS_LOCK_MASK (XFS_IOLOCK_EXCL | XFS_IOLOCK_SHARED \ - | XFS_ILOCK_EXCL | XFS_ILOCK_SHARED) + | XFS_ILOCK_EXCL | XFS_ILOCK_SHARED \ + | XFS_MMAPLOCK_EXCL | XFS_MMAPLOCK_SHARED) #define XFS_LOCK_FLAGS \ { XFS_IOLOCK_EXCL, "IOLOCK_EXCL" }, \ { XFS_IOLOCK_SHARED, "IOLOCK_SHARED" }, \ { XFS_ILOCK_EXCL, "ILOCK_EXCL" }, \ - { XFS_ILOCK_SHARED, "ILOCK_SHARED" } + { XFS_ILOCK_SHARED, "ILOCK_SHARED" }, \ + { XFS_MMAPLOCK_EXCL, "MMAPLOCK_EXCL" }, \ + { XFS_MMAPLOCK_SHARED, "MMAPLOCK_SHARED" } /* @@ -302,17 +308,26 @@ static inline int xfs_isiflocked(struct xfs_inode *ip) #define XFS_IOLOCK_SHIFT 16 #define XFS_IOLOCK_PARENT (XFS_LOCK_PARENT << XFS_IOLOCK_SHIFT) +#define XFS_MMAPLOCK_SHIFT 20 + #define XFS_ILOCK_SHIFT 24 #define XFS_ILOCK_PARENT (XFS_LOCK_PARENT << XFS_ILOCK_SHIFT) #define XFS_ILOCK_RTBITMAP (XFS_LOCK_RTBITMAP << XFS_ILOCK_SHIFT) #define XFS_ILOCK_RTSUM (XFS_LOCK_RTSUM << XFS_ILOCK_SHIFT) -#define XFS_IOLOCK_DEP_MASK 0x00ff0000 +#define XFS_IOLOCK_DEP_MASK 0x000f0000 +#define XFS_MMAPLOCK_DEP_MASK 0x00f00000 #define XFS_ILOCK_DEP_MASK 0xff000000 -#define XFS_LOCK_DEP_MASK (XFS_IOLOCK_DEP_MASK | XFS_ILOCK_DEP_MASK) - -#define XFS_IOLOCK_DEP(flags) (((flags) & XFS_IOLOCK_DEP_MASK) >> XFS_IOLOCK_SHIFT) -#define XFS_ILOCK_DEP(flags) (((flags) & XFS_ILOCK_DEP_MASK) >> XFS_ILOCK_SHIFT) +#define XFS_LOCK_DEP_MASK (XFS_IOLOCK_DEP_MASK | \ + XFS_MMAPLOCK_DEP_MASK | \ + XFS_ILOCK_DEP_MASK) + +#define XFS_IOLOCK_DEP(flags) (((flags) & XFS_IOLOCK_DEP_MASK) \ + >> XFS_IOLOCK_SHIFT) +#define XFS_MMAPLOCK_DEP(flags) (((flags) & XFS_MMAPLOCK_DEP_MASK) \ + >> XFS_MMAPLOCK_SHIFT) +#define XFS_ILOCK_DEP(flags) (((flags) & XFS_ILOCK_DEP_MASK) \ + >> XFS_ILOCK_SHIFT) /* * For multiple groups support: if S_ISGID bit is set in the parent diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c index 8fcc4ccc5c79..50c6fd3bd362 100644 --- a/fs/xfs/xfs_super.c +++ b/fs/xfs/xfs_super.c @@ -986,6 +986,8 @@ xfs_fs_inode_init_once( atomic_set(&ip->i_pincount, 0); spin_lock_init(&ip->i_flags_lock); + mrlock_init(&ip->i_mmaplock, MRLOCK_ALLOW_EQUAL_PRI|MRLOCK_BARRIER, + "xfsino", ip->i_ino); mrlock_init(&ip->i_lock, MRLOCK_ALLOW_EQUAL_PRI|MRLOCK_BARRIER, "xfsino", ip->i_ino); } |