* [PATCH 1/5] locking/lockdep: Provide a type check for lock_is_held
2016-11-29 17:28 an iomap-based direct I/O implementation V4 Christoph Hellwig
@ 2016-11-29 17:28 ` Christoph Hellwig
2016-11-29 17:28 ` [PATCH 2/5] xfs: remove i_iolock and use i_rwsem in the VFS inode instead Christoph Hellwig
` (5 subsequent siblings)
6 siblings, 0 replies; 8+ messages in thread
From: Christoph Hellwig @ 2016-11-29 17:28 UTC (permalink / raw)
To: linux-xfs; +Cc: axboe, linux-fsdevel, Peter Zijlstra
From: Peter Zijlstra <peterz@infradead.org>
Christoph requested lockdep_assert_held() variants that distinguish
between held-for-read or held-for-write.
Provide:
int lock_is_held_type(struct lockdep_map *lock, int read)
which takes the same argument as lock_acquire(.read) and matches it to
the held_lock instance.
Use of this function should be gated by the debug_locks variable. When
that is 0 the return value of the lock_is_held_type() function is
undefined. This is done to allow both negative and positive tests for
holding locks.
By default we provide (positive) lockdep_assert_held{,_exclusive,_read}()
macros.
Requested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
include/linux/lockdep.h | 25 +++++++++++++++++++++++--
kernel/locking/lockdep.c | 20 ++++++++++++--------
2 files changed, 35 insertions(+), 10 deletions(-)
diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h
index c1458fe..1e327bb 100644
--- a/include/linux/lockdep.h
+++ b/include/linux/lockdep.h
@@ -338,9 +338,18 @@ extern void lock_acquire(struct lockdep_map *lock, unsigned int subclass,
extern void lock_release(struct lockdep_map *lock, int nested,
unsigned long ip);
-#define lockdep_is_held(lock) lock_is_held(&(lock)->dep_map)
+/*
+ * Same "read" as for lock_acquire(), except -1 means any.
+ */
+extern int lock_is_held_type(struct lockdep_map *lock, int read);
+
+static inline int lock_is_held(struct lockdep_map *lock)
+{
+ return lock_is_held_type(lock, -1);
+}
-extern int lock_is_held(struct lockdep_map *lock);
+#define lockdep_is_held(lock) lock_is_held(&(lock)->dep_map)
+#define lockdep_is_held_type(lock, r) lock_is_held_type(&(lock)->dep_map, (r))
extern void lock_set_class(struct lockdep_map *lock, const char *name,
struct lock_class_key *key, unsigned int subclass,
@@ -372,6 +381,14 @@ extern void lock_unpin_lock(struct lockdep_map *lock, struct pin_cookie);
WARN_ON(debug_locks && !lockdep_is_held(l)); \
} while (0)
+#define lockdep_assert_held_exclusive(l) do { \
+ WARN_ON(debug_locks && !lockdep_is_held_type(l, 0)); \
+ } while (0)
+
+#define lockdep_assert_held_read(l) do { \
+ WARN_ON(debug_locks && !lockdep_is_held_type(l, 1)); \
+ } while (0)
+
#define lockdep_assert_held_once(l) do { \
WARN_ON_ONCE(debug_locks && !lockdep_is_held(l)); \
} while (0)
@@ -428,7 +445,11 @@ struct lock_class_key { };
#define lockdep_depth(tsk) (0)
+#define lockdep_is_held_type(l, r) (1)
+
#define lockdep_assert_held(l) do { (void)(l); } while (0)
+#define lockdep_assert_held_exclusive(l) do { (void)(l); } while (0)
+#define lockdep_assert_held_read(l) do { (void)(l); } while (0)
#define lockdep_assert_held_once(l) do { (void)(l); } while (0)
#define lockdep_recursing(tsk) (0)
diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index 589d763..cff580a 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -3188,7 +3188,7 @@ print_lock_nested_lock_not_held(struct task_struct *curr,
return 0;
}
-static int __lock_is_held(struct lockdep_map *lock);
+static int __lock_is_held(struct lockdep_map *lock, int read);
/*
* This gets called for every mutex_lock*()/spin_lock*() operation.
@@ -3329,7 +3329,7 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
}
chain_key = iterate_chain_key(chain_key, class_idx);
- if (nest_lock && !__lock_is_held(nest_lock))
+ if (nest_lock && !__lock_is_held(nest_lock, -1))
return print_lock_nested_lock_not_held(curr, hlock, ip);
if (!validate_chain(curr, lock, hlock, chain_head, chain_key))
@@ -3576,7 +3576,7 @@ __lock_release(struct lockdep_map *lock, int nested, unsigned long ip)
return 1;
}
-static int __lock_is_held(struct lockdep_map *lock)
+static int __lock_is_held(struct lockdep_map *lock, int read)
{
struct task_struct *curr = current;
int i;
@@ -3584,8 +3584,12 @@ static int __lock_is_held(struct lockdep_map *lock)
for (i = 0; i < curr->lockdep_depth; i++) {
struct held_lock *hlock = curr->held_locks + i;
- if (match_held_lock(hlock, lock))
- return 1;
+ if (match_held_lock(hlock, lock)) {
+ if (read == -1 || hlock->read == read)
+ return 1;
+
+ return 0;
+ }
}
return 0;
@@ -3769,7 +3773,7 @@ void lock_release(struct lockdep_map *lock, int nested,
}
EXPORT_SYMBOL_GPL(lock_release);
-int lock_is_held(struct lockdep_map *lock)
+int lock_is_held_type(struct lockdep_map *lock, int read)
{
unsigned long flags;
int ret = 0;
@@ -3781,13 +3785,13 @@ int lock_is_held(struct lockdep_map *lock)
check_flags(flags);
current->lockdep_recursion = 1;
- ret = __lock_is_held(lock);
+ ret = __lock_is_held(lock, read);
current->lockdep_recursion = 0;
raw_local_irq_restore(flags);
return ret;
}
-EXPORT_SYMBOL_GPL(lock_is_held);
+EXPORT_SYMBOL_GPL(lock_is_held_type);
struct pin_cookie lock_pin_lock(struct lockdep_map *lock)
{
--
2.1.4
^ permalink raw reply related [flat|nested] 8+ messages in thread* [PATCH 2/5] xfs: remove i_iolock and use i_rwsem in the VFS inode instead
2016-11-29 17:28 an iomap-based direct I/O implementation V4 Christoph Hellwig
2016-11-29 17:28 ` [PATCH 1/5] locking/lockdep: Provide a type check for lock_is_held Christoph Hellwig
@ 2016-11-29 17:28 ` Christoph Hellwig
2016-11-29 17:28 ` [PATCH 3/5] fs: make sb_init_dio_done_wq available outside of direct-io.c Christoph Hellwig
` (4 subsequent siblings)
6 siblings, 0 replies; 8+ messages in thread
From: Christoph Hellwig @ 2016-11-29 17:28 UTC (permalink / raw)
To: linux-xfs; +Cc: axboe, linux-fsdevel
This patch drops the XFS-own i_iolock and uses the VFS i_rwsem which
recently replaced i_mutex instead. This means we only have to take
one looks instead of two in many fast path operations, and we can
also shrink the xfs_inode structure. Thanks to the xfs_ilock family
there is very little churn, the only thing of note is that we need
to switch to use the lock_two_directory helper for taking the i_rwsem
on two inodes in a few places to make sure our lock order matches
the one used in the VFS.
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
fs/xfs/xfs_aops.c | 7 ++--
fs/xfs/xfs_bmap_util.c | 12 +++----
fs/xfs/xfs_dir2_readdir.c | 2 --
fs/xfs/xfs_file.c | 79 +++++++++++++--------------------------------
fs/xfs/xfs_icache.c | 6 ++--
fs/xfs/xfs_inode.c | 82 +++++++++++++++++++----------------------------
fs/xfs/xfs_inode.h | 7 ++--
fs/xfs/xfs_ioctl.c | 2 +-
fs/xfs/xfs_iops.c | 14 ++++----
fs/xfs/xfs_pnfs.c | 7 +---
fs/xfs/xfs_pnfs.h | 4 +--
fs/xfs/xfs_reflink.c | 14 +++-----
fs/xfs/xfs_super.c | 2 +-
fs/xfs/xfs_symlink.c | 7 ++--
14 files changed, 86 insertions(+), 159 deletions(-)
diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c
index ab266d6..e8f6c2b 100644
--- a/fs/xfs/xfs_aops.c
+++ b/fs/xfs/xfs_aops.c
@@ -1585,7 +1585,6 @@ xfs_vm_bmap(
struct xfs_inode *ip = XFS_I(inode);
trace_xfs_vm_bmap(XFS_I(inode));
- xfs_ilock(ip, XFS_IOLOCK_SHARED);
/*
* The swap code (ab-)uses ->bmap to get a block mapping and then
@@ -1593,12 +1592,10 @@ xfs_vm_bmap(
* that on reflinks inodes, so we have to skip out here. And yes,
* 0 is the magic code for a bmap error..
*/
- if (xfs_is_reflink_inode(ip)) {
- xfs_iunlock(ip, XFS_IOLOCK_SHARED);
+ if (xfs_is_reflink_inode(ip))
return 0;
- }
+
filemap_write_and_wait(mapping);
- xfs_iunlock(ip, XFS_IOLOCK_SHARED);
return generic_block_bmap(mapping, block, xfs_get_blocks);
}
diff --git a/fs/xfs/xfs_bmap_util.c b/fs/xfs/xfs_bmap_util.c
index 0670a8b..b9abce5 100644
--- a/fs/xfs/xfs_bmap_util.c
+++ b/fs/xfs/xfs_bmap_util.c
@@ -1935,8 +1935,8 @@ xfs_swap_extents(
* page cache safely. Once we have done this we can take the ilocks and
* do the rest of the checks.
*/
- lock_flags = XFS_IOLOCK_EXCL | XFS_MMAPLOCK_EXCL;
- xfs_lock_two_inodes(ip, tip, XFS_IOLOCK_EXCL);
+ lock_two_nondirectories(VFS_I(ip), VFS_I(tip));
+ lock_flags = XFS_MMAPLOCK_EXCL;
xfs_lock_two_inodes(ip, tip, XFS_MMAPLOCK_EXCL);
/* Verify that both files have the same format */
@@ -2076,15 +2076,13 @@ xfs_swap_extents(
trace_xfs_swap_extent_after(ip, 0);
trace_xfs_swap_extent_after(tip, 1);
+out_unlock:
xfs_iunlock(ip, lock_flags);
xfs_iunlock(tip, lock_flags);
+ unlock_two_nondirectories(VFS_I(ip), VFS_I(tip));
return error;
out_trans_cancel:
xfs_trans_cancel(tp);
-
-out_unlock:
- xfs_iunlock(ip, lock_flags);
- xfs_iunlock(tip, lock_flags);
- return error;
+ goto out_unlock;
}
diff --git a/fs/xfs/xfs_dir2_readdir.c b/fs/xfs/xfs_dir2_readdir.c
index 2981698..003a99b 100644
--- a/fs/xfs/xfs_dir2_readdir.c
+++ b/fs/xfs/xfs_dir2_readdir.c
@@ -677,7 +677,6 @@ xfs_readdir(
args.dp = dp;
args.geo = dp->i_mount->m_dir_geo;
- xfs_ilock(dp, XFS_IOLOCK_SHARED);
if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL)
rval = xfs_dir2_sf_getdents(&args, ctx);
else if ((rval = xfs_dir2_isblock(&args, &v)))
@@ -686,7 +685,6 @@ xfs_readdir(
rval = xfs_dir2_block_getdents(&args, ctx);
else
rval = xfs_dir2_leaf_getdents(&args, ctx, bufsize);
- xfs_iunlock(dp, XFS_IOLOCK_SHARED);
return rval;
}
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index d818c16..d054b73 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -48,40 +48,6 @@
static const struct vm_operations_struct xfs_file_vm_ops;
/*
- * Locking primitives for read and write IO paths to ensure we consistently use
- * and order the inode->i_mutex, ip->i_lock and ip->i_iolock.
- */
-static inline void
-xfs_rw_ilock(
- struct xfs_inode *ip,
- int type)
-{
- if (type & XFS_IOLOCK_EXCL)
- inode_lock(VFS_I(ip));
- xfs_ilock(ip, type);
-}
-
-static inline void
-xfs_rw_iunlock(
- struct xfs_inode *ip,
- int type)
-{
- xfs_iunlock(ip, type);
- if (type & XFS_IOLOCK_EXCL)
- inode_unlock(VFS_I(ip));
-}
-
-static inline void
-xfs_rw_ilock_demote(
- struct xfs_inode *ip,
- int type)
-{
- xfs_ilock_demote(ip, type);
- if (type & XFS_IOLOCK_EXCL)
- inode_unlock(VFS_I(ip));
-}
-
-/*
* Clear the specified ranges to zero through either the pagecache or DAX.
* Holes and unwritten extents will be left as-is as they already are zeroed.
*/
@@ -273,7 +239,7 @@ xfs_file_dio_aio_read(
file_accessed(iocb->ki_filp);
- xfs_rw_ilock(ip, XFS_IOLOCK_SHARED);
+ xfs_ilock(ip, XFS_IOLOCK_SHARED);
if (mapping->nrpages) {
ret = filemap_write_and_wait_range(mapping, iocb->ki_pos, end);
if (ret)
@@ -299,7 +265,7 @@ xfs_file_dio_aio_read(
}
out_unlock:
- xfs_rw_iunlock(ip, XFS_IOLOCK_SHARED);
+ xfs_iunlock(ip, XFS_IOLOCK_SHARED);
return ret;
}
@@ -317,9 +283,9 @@ xfs_file_dax_read(
if (!count)
return 0; /* skip atime */
- xfs_rw_ilock(ip, XFS_IOLOCK_SHARED);
+ xfs_ilock(ip, XFS_IOLOCK_SHARED);
ret = dax_iomap_rw(iocb, to, &xfs_iomap_ops);
- xfs_rw_iunlock(ip, XFS_IOLOCK_SHARED);
+ xfs_iunlock(ip, XFS_IOLOCK_SHARED);
file_accessed(iocb->ki_filp);
return ret;
@@ -335,9 +301,9 @@ xfs_file_buffered_aio_read(
trace_xfs_file_buffered_read(ip, iov_iter_count(to), iocb->ki_pos);
- xfs_rw_ilock(ip, XFS_IOLOCK_SHARED);
+ xfs_ilock(ip, XFS_IOLOCK_SHARED);
ret = generic_file_read_iter(iocb, to);
- xfs_rw_iunlock(ip, XFS_IOLOCK_SHARED);
+ xfs_iunlock(ip, XFS_IOLOCK_SHARED);
return ret;
}
@@ -418,15 +384,18 @@ xfs_file_aio_write_checks(
if (error <= 0)
return error;
- error = xfs_break_layouts(inode, iolock, true);
+ error = xfs_break_layouts(inode, iolock);
if (error)
return error;
- /* For changing security info in file_remove_privs() we need i_mutex */
+ /*
+ * For changing security info in file_remove_privs() we need i_rwsem
+ * exclusively.
+ */
if (*iolock == XFS_IOLOCK_SHARED && !IS_NOSEC(inode)) {
- xfs_rw_iunlock(ip, *iolock);
+ xfs_iunlock(ip, *iolock);
*iolock = XFS_IOLOCK_EXCL;
- xfs_rw_ilock(ip, *iolock);
+ xfs_ilock(ip, *iolock);
goto restart;
}
/*
@@ -451,9 +420,9 @@ xfs_file_aio_write_checks(
spin_unlock(&ip->i_flags_lock);
if (!drained_dio) {
if (*iolock == XFS_IOLOCK_SHARED) {
- xfs_rw_iunlock(ip, *iolock);
+ xfs_iunlock(ip, *iolock);
*iolock = XFS_IOLOCK_EXCL;
- xfs_rw_ilock(ip, *iolock);
+ xfs_ilock(ip, *iolock);
iov_iter_reexpand(from, count);
}
/*
@@ -559,7 +528,7 @@ xfs_file_dio_aio_write(
iolock = XFS_IOLOCK_SHARED;
}
- xfs_rw_ilock(ip, iolock);
+ xfs_ilock(ip, iolock);
ret = xfs_file_aio_write_checks(iocb, from, &iolock);
if (ret)
@@ -591,7 +560,7 @@ xfs_file_dio_aio_write(
if (unaligned_io)
inode_dio_wait(inode);
else if (iolock == XFS_IOLOCK_EXCL) {
- xfs_rw_ilock_demote(ip, XFS_IOLOCK_EXCL);
+ xfs_ilock_demote(ip, XFS_IOLOCK_EXCL);
iolock = XFS_IOLOCK_SHARED;
}
@@ -621,7 +590,7 @@ xfs_file_dio_aio_write(
iov_iter_advance(from, ret);
}
out:
- xfs_rw_iunlock(ip, iolock);
+ xfs_iunlock(ip, iolock);
/*
* No fallback to buffered IO on errors for XFS, direct IO will either
@@ -643,7 +612,7 @@ xfs_file_dax_write(
size_t count;
loff_t pos;
- xfs_rw_ilock(ip, iolock);
+ xfs_ilock(ip, iolock);
ret = xfs_file_aio_write_checks(iocb, from, &iolock);
if (ret)
goto out;
@@ -652,15 +621,13 @@ xfs_file_dax_write(
count = iov_iter_count(from);
trace_xfs_file_dax_write(ip, count, pos);
-
ret = dax_iomap_rw(iocb, from, &xfs_iomap_ops);
if (ret > 0 && iocb->ki_pos > i_size_read(inode)) {
i_size_write(inode, iocb->ki_pos);
error = xfs_setfilesize(ip, pos, ret);
}
-
out:
- xfs_rw_iunlock(ip, iolock);
+ xfs_iunlock(ip, iolock);
return error ? error : ret;
}
@@ -677,7 +644,7 @@ xfs_file_buffered_aio_write(
int enospc = 0;
int iolock = XFS_IOLOCK_EXCL;
- xfs_rw_ilock(ip, iolock);
+ xfs_ilock(ip, iolock);
ret = xfs_file_aio_write_checks(iocb, from, &iolock);
if (ret)
@@ -721,7 +688,7 @@ xfs_file_buffered_aio_write(
current->backing_dev_info = NULL;
out:
- xfs_rw_iunlock(ip, iolock);
+ xfs_iunlock(ip, iolock);
return ret;
}
@@ -797,7 +764,7 @@ xfs_file_fallocate(
return -EOPNOTSUPP;
xfs_ilock(ip, iolock);
- error = xfs_break_layouts(inode, &iolock, false);
+ error = xfs_break_layouts(inode, &iolock);
if (error)
goto out_unlock;
diff --git a/fs/xfs/xfs_icache.c b/fs/xfs/xfs_icache.c
index 9c3e5c6..ff4d631 100644
--- a/fs/xfs/xfs_icache.c
+++ b/fs/xfs/xfs_icache.c
@@ -70,8 +70,6 @@ xfs_inode_alloc(
ASSERT(!xfs_isiflocked(ip));
ASSERT(ip->i_ino == 0);
- mrlock_init(&ip->i_iolock, MRLOCK_BARRIER, "xfsio", ip->i_ino);
-
/* initialise the xfs inode */
ip->i_ino = ino;
ip->i_mount = mp;
@@ -394,8 +392,8 @@ xfs_iget_cache_hit(
xfs_inode_clear_reclaim_tag(pag, ip->i_ino);
inode->i_state = I_NEW;
- ASSERT(!rwsem_is_locked(&ip->i_iolock.mr_lock));
- mrlock_init(&ip->i_iolock, MRLOCK_BARRIER, "xfsio", ip->i_ino);
+ ASSERT(!rwsem_is_locked(&inode->i_rwsem));
+ init_rwsem(&inode->i_rwsem);
spin_unlock(&ip->i_flags_lock);
spin_unlock(&pag->pag_ici_lock);
diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
index 4e560e6..e9ab42d 100644
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c
@@ -142,31 +142,31 @@ xfs_ilock_attr_map_shared(
}
/*
- * 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.
+ * In addition to i_rwsem in the VFS inode, the xfs inode contains 2
+ * multi-reader locks: i_mmap_lock and the i_lock. This routine allows
+ * various combinations of the locks to be obtained.
*
* 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.
*
* Basic locking order:
*
- * i_iolock -> i_mmap_lock -> page_lock -> i_ilock
+ * i_rwsem -> i_mmap_lock -> page_lock -> i_ilock
*
* mmap_sem locking order:
*
- * i_iolock -> page lock -> mmap_sem
+ * i_rwsem -> 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
+ * direct IO. Similarly the i_rwsem 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
+ * take both the i_rwsem 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).
@@ -191,10 +191,13 @@ xfs_ilock(
(XFS_ILOCK_SHARED | XFS_ILOCK_EXCL));
ASSERT((lock_flags & ~(XFS_LOCK_MASK | XFS_LOCK_SUBCLASS_MASK)) == 0);
- if (lock_flags & XFS_IOLOCK_EXCL)
- mrupdate_nested(&ip->i_iolock, XFS_IOLOCK_DEP(lock_flags));
- else if (lock_flags & XFS_IOLOCK_SHARED)
- mraccess_nested(&ip->i_iolock, XFS_IOLOCK_DEP(lock_flags));
+ if (lock_flags & XFS_IOLOCK_EXCL) {
+ down_write_nested(&VFS_I(ip)->i_rwsem,
+ XFS_IOLOCK_DEP(lock_flags));
+ } else if (lock_flags & XFS_IOLOCK_SHARED) {
+ down_read_nested(&VFS_I(ip)->i_rwsem,
+ XFS_IOLOCK_DEP(lock_flags));
+ }
if (lock_flags & XFS_MMAPLOCK_EXCL)
mrupdate_nested(&ip->i_mmaplock, XFS_MMAPLOCK_DEP(lock_flags));
@@ -240,10 +243,10 @@ xfs_ilock_nowait(
ASSERT((lock_flags & ~(XFS_LOCK_MASK | XFS_LOCK_SUBCLASS_MASK)) == 0);
if (lock_flags & XFS_IOLOCK_EXCL) {
- if (!mrtryupdate(&ip->i_iolock))
+ if (!down_write_trylock(&VFS_I(ip)->i_rwsem))
goto out;
} else if (lock_flags & XFS_IOLOCK_SHARED) {
- if (!mrtryaccess(&ip->i_iolock))
+ if (!down_read_trylock(&VFS_I(ip)->i_rwsem))
goto out;
}
@@ -271,9 +274,9 @@ xfs_ilock_nowait(
mrunlock_shared(&ip->i_mmaplock);
out_undo_iolock:
if (lock_flags & XFS_IOLOCK_EXCL)
- mrunlock_excl(&ip->i_iolock);
+ up_write(&VFS_I(ip)->i_rwsem);
else if (lock_flags & XFS_IOLOCK_SHARED)
- mrunlock_shared(&ip->i_iolock);
+ up_read(&VFS_I(ip)->i_rwsem);
out:
return 0;
}
@@ -310,9 +313,9 @@ xfs_iunlock(
ASSERT(lock_flags != 0);
if (lock_flags & XFS_IOLOCK_EXCL)
- mrunlock_excl(&ip->i_iolock);
+ up_write(&VFS_I(ip)->i_rwsem);
else if (lock_flags & XFS_IOLOCK_SHARED)
- mrunlock_shared(&ip->i_iolock);
+ up_read(&VFS_I(ip)->i_rwsem);
if (lock_flags & XFS_MMAPLOCK_EXCL)
mrunlock_excl(&ip->i_mmaplock);
@@ -345,7 +348,7 @@ xfs_ilock_demote(
if (lock_flags & XFS_MMAPLOCK_EXCL)
mrdemote(&ip->i_mmaplock);
if (lock_flags & XFS_IOLOCK_EXCL)
- mrdemote(&ip->i_iolock);
+ downgrade_write(&VFS_I(ip)->i_rwsem);
trace_xfs_ilock_demote(ip, lock_flags, _RET_IP_);
}
@@ -370,8 +373,9 @@ xfs_isilocked(
if (lock_flags & (XFS_IOLOCK_EXCL|XFS_IOLOCK_SHARED)) {
if (!(lock_flags & XFS_IOLOCK_SHARED))
- return !!ip->i_iolock.mr_writer;
- return rwsem_is_locked(&ip->i_iolock.mr_lock);
+ return !debug_locks ||
+ lockdep_is_held_type(&VFS_I(ip)->i_rwsem, 0);
+ return rwsem_is_locked(&VFS_I(ip)->i_rwsem);
}
ASSERT(0);
@@ -421,11 +425,7 @@ xfs_lock_inumorder(int lock_mode, int subclass)
if (lock_mode & (XFS_IOLOCK_SHARED|XFS_IOLOCK_EXCL)) {
ASSERT(subclass <= XFS_IOLOCK_MAX_SUBCLASS);
- ASSERT(xfs_lockdep_subclass_ok(subclass +
- XFS_IOLOCK_PARENT_VAL));
class += subclass << XFS_IOLOCK_SHIFT;
- if (lock_mode & XFS_IOLOCK_PARENT)
- class += XFS_IOLOCK_PARENT_VAL << XFS_IOLOCK_SHIFT;
}
if (lock_mode & (XFS_MMAPLOCK_SHARED|XFS_MMAPLOCK_EXCL)) {
@@ -477,8 +477,6 @@ xfs_lock_inodes(
XFS_ILOCK_EXCL));
ASSERT(!(lock_mode & (XFS_IOLOCK_SHARED | XFS_MMAPLOCK_SHARED |
XFS_ILOCK_SHARED)));
- ASSERT(!(lock_mode & XFS_IOLOCK_EXCL) ||
- inodes <= XFS_IOLOCK_MAX_SUBCLASS + 1);
ASSERT(!(lock_mode & XFS_MMAPLOCK_EXCL) ||
inodes <= XFS_MMAPLOCK_MAX_SUBCLASS + 1);
ASSERT(!(lock_mode & XFS_ILOCK_EXCL) ||
@@ -581,10 +579,8 @@ 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_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_IOLOCK_SHARED|XFS_IOLOCK_EXCL)));
+ 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);
@@ -715,7 +711,6 @@ xfs_lookup(
if (XFS_FORCED_SHUTDOWN(dp->i_mount))
return -EIO;
- xfs_ilock(dp, XFS_IOLOCK_SHARED);
error = xfs_dir_lookup(NULL, dp, name, &inum, ci_name);
if (error)
goto out_unlock;
@@ -724,14 +719,12 @@ xfs_lookup(
if (error)
goto out_free_name;
- xfs_iunlock(dp, XFS_IOLOCK_SHARED);
return 0;
out_free_name:
if (ci_name)
kmem_free(ci_name->name);
out_unlock:
- xfs_iunlock(dp, XFS_IOLOCK_SHARED);
*ipp = NULL;
return error;
}
@@ -1215,8 +1208,7 @@ xfs_create(
if (error)
goto out_release_inode;
- xfs_ilock(dp, XFS_IOLOCK_EXCL | XFS_ILOCK_EXCL |
- XFS_IOLOCK_PARENT | XFS_ILOCK_PARENT);
+ xfs_ilock(dp, XFS_ILOCK_EXCL | XFS_ILOCK_PARENT);
unlock_dp_on_error = true;
xfs_defer_init(&dfops, &first_block);
@@ -1252,7 +1244,7 @@ xfs_create(
* the transaction cancel unlocking dp so don't do it explicitly in the
* error path.
*/
- xfs_trans_ijoin(tp, dp, XFS_IOLOCK_EXCL | XFS_ILOCK_EXCL);
+ xfs_trans_ijoin(tp, dp, XFS_ILOCK_EXCL);
unlock_dp_on_error = false;
error = xfs_dir_createname(tp, dp, name, ip->i_ino,
@@ -1325,7 +1317,7 @@ xfs_create(
xfs_qm_dqrele(pdqp);
if (unlock_dp_on_error)
- xfs_iunlock(dp, XFS_IOLOCK_EXCL | XFS_ILOCK_EXCL);
+ xfs_iunlock(dp, XFS_ILOCK_EXCL);
return error;
}
@@ -1466,11 +1458,10 @@ xfs_link(
if (error)
goto std_return;
- xfs_ilock(tdp, XFS_IOLOCK_EXCL | XFS_IOLOCK_PARENT);
xfs_lock_two_inodes(sip, tdp, XFS_ILOCK_EXCL);
xfs_trans_ijoin(tp, sip, XFS_ILOCK_EXCL);
- xfs_trans_ijoin(tp, tdp, XFS_IOLOCK_EXCL | XFS_ILOCK_EXCL);
+ xfs_trans_ijoin(tp, tdp, XFS_ILOCK_EXCL);
/*
* If we are using project inheritance, we only allow hard link
@@ -2579,10 +2570,9 @@ xfs_remove(
goto std_return;
}
- xfs_ilock(dp, XFS_IOLOCK_EXCL | XFS_IOLOCK_PARENT);
xfs_lock_two_inodes(dp, ip, XFS_ILOCK_EXCL);
- xfs_trans_ijoin(tp, dp, XFS_IOLOCK_EXCL | XFS_ILOCK_EXCL);
+ xfs_trans_ijoin(tp, dp, XFS_ILOCK_EXCL);
xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
/*
@@ -2963,12 +2953,6 @@ xfs_rename(
* whether the target directory is the same as the source
* directory, we can lock from 2 to 4 inodes.
*/
- if (!new_parent)
- xfs_ilock(src_dp, XFS_IOLOCK_EXCL | XFS_IOLOCK_PARENT);
- else
- xfs_lock_two_inodes(src_dp, target_dp,
- XFS_IOLOCK_EXCL | XFS_IOLOCK_PARENT);
-
xfs_lock_inodes(inodes, num_inodes, XFS_ILOCK_EXCL);
/*
@@ -2976,9 +2960,9 @@ xfs_rename(
* we can rely on either trans_commit or trans_cancel to unlock
* them.
*/
- xfs_trans_ijoin(tp, src_dp, XFS_IOLOCK_EXCL | XFS_ILOCK_EXCL);
+ xfs_trans_ijoin(tp, src_dp, XFS_ILOCK_EXCL);
if (new_parent)
- xfs_trans_ijoin(tp, target_dp, XFS_IOLOCK_EXCL | XFS_ILOCK_EXCL);
+ xfs_trans_ijoin(tp, target_dp, XFS_ILOCK_EXCL);
xfs_trans_ijoin(tp, src_ip, XFS_ILOCK_EXCL);
if (target_ip)
xfs_trans_ijoin(tp, target_ip, XFS_ILOCK_EXCL);
diff --git a/fs/xfs/xfs_inode.h b/fs/xfs/xfs_inode.h
index 71e8a81..10dcf27 100644
--- a/fs/xfs/xfs_inode.h
+++ b/fs/xfs/xfs_inode.h
@@ -56,7 +56,6 @@ typedef struct xfs_inode {
/* Transaction and locking information. */
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 */
@@ -333,7 +332,7 @@ static inline void xfs_ifunlock(struct xfs_inode *ip)
* IOLOCK values
*
* 0-3 subclass value
- * 4-7 PARENT subclass values
+ * 4-7 unused
*
* MMAPLOCK values
*
@@ -348,10 +347,8 @@ static inline void xfs_ifunlock(struct xfs_inode *ip)
*
*/
#define XFS_IOLOCK_SHIFT 16
-#define XFS_IOLOCK_PARENT_VAL 4
-#define XFS_IOLOCK_MAX_SUBCLASS (XFS_IOLOCK_PARENT_VAL - 1)
+#define XFS_IOLOCK_MAX_SUBCLASS 3
#define XFS_IOLOCK_DEP_MASK 0x000f0000
-#define XFS_IOLOCK_PARENT (XFS_IOLOCK_PARENT_VAL << XFS_IOLOCK_SHIFT)
#define XFS_MMAPLOCK_SHIFT 20
#define XFS_MMAPLOCK_NUMORDER 0
diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c
index a391975..fc563b8 100644
--- a/fs/xfs/xfs_ioctl.c
+++ b/fs/xfs/xfs_ioctl.c
@@ -639,7 +639,7 @@ xfs_ioc_space(
return error;
xfs_ilock(ip, iolock);
- error = xfs_break_layouts(inode, &iolock, false);
+ error = xfs_break_layouts(inode, &iolock);
if (error)
goto out_unlock;
diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c
index 405a65c..c962999 100644
--- a/fs/xfs/xfs_iops.c
+++ b/fs/xfs/xfs_iops.c
@@ -983,15 +983,13 @@ xfs_vn_setattr(
struct xfs_inode *ip = XFS_I(d_inode(dentry));
uint iolock = XFS_IOLOCK_EXCL;
- xfs_ilock(ip, iolock);
- error = xfs_break_layouts(d_inode(dentry), &iolock, true);
- if (!error) {
- xfs_ilock(ip, XFS_MMAPLOCK_EXCL);
- iolock |= XFS_MMAPLOCK_EXCL;
+ error = xfs_break_layouts(d_inode(dentry), &iolock);
+ if (error)
+ return error;
- error = xfs_vn_setattr_size(dentry, iattr);
- }
- xfs_iunlock(ip, iolock);
+ xfs_ilock(ip, XFS_MMAPLOCK_EXCL);
+ error = xfs_setattr_size(ip, iattr);
+ xfs_iunlock(ip, XFS_MMAPLOCK_EXCL);
} else {
error = xfs_vn_setattr_nonsize(dentry, iattr);
}
diff --git a/fs/xfs/xfs_pnfs.c b/fs/xfs/xfs_pnfs.c
index 93a7aaf..2f2dc3c 100644
--- a/fs/xfs/xfs_pnfs.c
+++ b/fs/xfs/xfs_pnfs.c
@@ -32,8 +32,7 @@
int
xfs_break_layouts(
struct inode *inode,
- uint *iolock,
- bool with_imutex)
+ uint *iolock)
{
struct xfs_inode *ip = XFS_I(inode);
int error;
@@ -42,12 +41,8 @@ xfs_break_layouts(
while ((error = break_layout(inode, false) == -EWOULDBLOCK)) {
xfs_iunlock(ip, *iolock);
- if (with_imutex && (*iolock & XFS_IOLOCK_EXCL))
- inode_unlock(inode);
error = break_layout(inode, true);
*iolock = XFS_IOLOCK_EXCL;
- if (with_imutex)
- inode_lock(inode);
xfs_ilock(ip, *iolock);
}
diff --git a/fs/xfs/xfs_pnfs.h b/fs/xfs/xfs_pnfs.h
index e8339f7..b587cb9 100644
--- a/fs/xfs/xfs_pnfs.h
+++ b/fs/xfs/xfs_pnfs.h
@@ -8,10 +8,10 @@ int xfs_fs_map_blocks(struct inode *inode, loff_t offset, u64 length,
int xfs_fs_commit_blocks(struct inode *inode, struct iomap *maps, int nr_maps,
struct iattr *iattr);
-int xfs_break_layouts(struct inode *inode, uint *iolock, bool with_imutex);
+int xfs_break_layouts(struct inode *inode, uint *iolock);
#else
static inline int
-xfs_break_layouts(struct inode *inode, uint *iolock, bool with_imutex)
+xfs_break_layouts(struct inode *inode, uint *iolock)
{
return 0;
}
diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c
index becf246..88fd03c 100644
--- a/fs/xfs/xfs_reflink.c
+++ b/fs/xfs/xfs_reflink.c
@@ -1251,13 +1251,11 @@ xfs_reflink_remap_range(
return -EIO;
/* Lock both files against IO */
- if (same_inode) {
- xfs_ilock(src, XFS_IOLOCK_EXCL);
+ lock_two_nondirectories(inode_in, inode_out);
+ if (same_inode)
xfs_ilock(src, XFS_MMAPLOCK_EXCL);
- } else {
- xfs_lock_two_inodes(src, dest, XFS_IOLOCK_EXCL);
+ else
xfs_lock_two_inodes(src, dest, XFS_MMAPLOCK_EXCL);
- }
/* Don't touch certain kinds of inodes */
ret = -EPERM;
@@ -1402,11 +1400,9 @@ xfs_reflink_remap_range(
out_unlock:
xfs_iunlock(src, XFS_MMAPLOCK_EXCL);
- xfs_iunlock(src, XFS_IOLOCK_EXCL);
- if (src->i_ino != dest->i_ino) {
+ if (!same_inode)
xfs_iunlock(dest, XFS_MMAPLOCK_EXCL);
- xfs_iunlock(dest, XFS_IOLOCK_EXCL);
- }
+ unlock_two_nondirectories(inode_in, inode_out);
if (ret)
trace_xfs_reflink_remap_range_error(dest, ret, _RET_IP_);
return ret;
diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index ade4691..563d1d1 100644
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c
@@ -943,7 +943,7 @@ xfs_fs_destroy_inode(
trace_xfs_destroy_inode(ip);
- ASSERT(!rwsem_is_locked(&ip->i_iolock.mr_lock));
+ ASSERT(!rwsem_is_locked(&inode->i_rwsem));
XFS_STATS_INC(ip->i_mount, vn_rele);
XFS_STATS_INC(ip->i_mount, vn_remove);
diff --git a/fs/xfs/xfs_symlink.c b/fs/xfs/xfs_symlink.c
index 58142ae..f2cb45e 100644
--- a/fs/xfs/xfs_symlink.c
+++ b/fs/xfs/xfs_symlink.c
@@ -238,8 +238,7 @@ xfs_symlink(
if (error)
goto out_release_inode;
- xfs_ilock(dp, XFS_IOLOCK_EXCL | XFS_ILOCK_EXCL |
- XFS_IOLOCK_PARENT | XFS_ILOCK_PARENT);
+ xfs_ilock(dp, XFS_ILOCK_EXCL | XFS_ILOCK_PARENT);
unlock_dp_on_error = true;
/*
@@ -287,7 +286,7 @@ xfs_symlink(
* the transaction cancel unlocking dp so don't do it explicitly in the
* error path.
*/
- xfs_trans_ijoin(tp, dp, XFS_IOLOCK_EXCL | XFS_ILOCK_EXCL);
+ xfs_trans_ijoin(tp, dp, XFS_ILOCK_EXCL);
unlock_dp_on_error = false;
/*
@@ -412,7 +411,7 @@ xfs_symlink(
xfs_qm_dqrele(pdqp);
if (unlock_dp_on_error)
- xfs_iunlock(dp, XFS_IOLOCK_EXCL | XFS_ILOCK_EXCL);
+ xfs_iunlock(dp, XFS_ILOCK_EXCL);
return error;
}
--
2.1.4
^ permalink raw reply related [flat|nested] 8+ messages in thread* [PATCH 3/5] fs: make sb_init_dio_done_wq available outside of direct-io.c
2016-11-29 17:28 an iomap-based direct I/O implementation V4 Christoph Hellwig
2016-11-29 17:28 ` [PATCH 1/5] locking/lockdep: Provide a type check for lock_is_held Christoph Hellwig
2016-11-29 17:28 ` [PATCH 2/5] xfs: remove i_iolock and use i_rwsem in the VFS inode instead Christoph Hellwig
@ 2016-11-29 17:28 ` Christoph Hellwig
2016-11-29 17:28 ` [PATCH 4/5] iomap: implement direct I/O Christoph Hellwig
` (3 subsequent siblings)
6 siblings, 0 replies; 8+ messages in thread
From: Christoph Hellwig @ 2016-11-29 17:28 UTC (permalink / raw)
To: linux-xfs; +Cc: axboe, linux-fsdevel
We want to use the per-sb completion workqueue from the new iomap
direct I/O code.
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
fs/direct-io.c | 2 +-
fs/internal.h | 3 +++
2 files changed, 4 insertions(+), 1 deletion(-)
diff --git a/fs/direct-io.c b/fs/direct-io.c
index fb9aa16..19aa448 100644
--- a/fs/direct-io.c
+++ b/fs/direct-io.c
@@ -554,7 +554,7 @@ static inline int dio_bio_reap(struct dio *dio, struct dio_submit *sdio)
* filesystems that don't need it and also allows us to create the workqueue
* late enough so the we can include s_id in the name of the workqueue.
*/
-static int sb_init_dio_done_wq(struct super_block *sb)
+int sb_init_dio_done_wq(struct super_block *sb)
{
struct workqueue_struct *old;
struct workqueue_struct *wq = alloc_workqueue("dio/%s",
diff --git a/fs/internal.h b/fs/internal.h
index f4da334..4fcf517 100644
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -184,3 +184,6 @@ typedef loff_t (*iomap_actor_t)(struct inode *inode, loff_t pos, loff_t len,
loff_t iomap_apply(struct inode *inode, loff_t pos, loff_t length,
unsigned flags, struct iomap_ops *ops, void *data,
iomap_actor_t actor);
+
+/* direct-io.c: */
+int sb_init_dio_done_wq(struct super_block *sb);
--
2.1.4
^ permalink raw reply related [flat|nested] 8+ messages in thread* [PATCH 4/5] iomap: implement direct I/O
2016-11-29 17:28 an iomap-based direct I/O implementation V4 Christoph Hellwig
` (2 preceding siblings ...)
2016-11-29 17:28 ` [PATCH 3/5] fs: make sb_init_dio_done_wq available outside of direct-io.c Christoph Hellwig
@ 2016-11-29 17:28 ` Christoph Hellwig
2016-11-29 17:28 ` [PATCH 5/5] xfs: use iomap_dio_rw Christoph Hellwig
` (2 subsequent siblings)
6 siblings, 0 replies; 8+ messages in thread
From: Christoph Hellwig @ 2016-11-29 17:28 UTC (permalink / raw)
To: linux-xfs; +Cc: axboe, linux-fsdevel
This adds a full fledget direct I/O implementation using the iomap
interface. Full fledged in this case means all features are supported:
AIO, vectored I/O, any iov_iter type including kernel pointers, bvecs
and pipes, support for hole filling and async apending writes. It does
not mean supporting all the warts of the old generic code. We expect
i_rwsem to be held over the duration of the call, and we expect to
maintain i_dio_count ourselves, and we pass on any kinds of mapping
to the file system for now.
The algorithm used is very simple: We use iomap_apply to iterate over
the range of the I/O, and then we use the new bio_iov_iter_get_pages
helper to lock down the user range for the size of the extent.
bio_iov_iter_get_pages can currently lock down twice as many pages as
the old direct I/O code did, which means that we will have a better
batch factor for everything but overwrites of badly fragmented files.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com>
---
fs/iomap.c | 373 ++++++++++++++++++++++++++++++++++++++++++++++++++
include/linux/iomap.h | 11 ++
2 files changed, 384 insertions(+)
diff --git a/fs/iomap.c b/fs/iomap.c
index 13dd413..93d36fd 100644
--- a/fs/iomap.c
+++ b/fs/iomap.c
@@ -24,6 +24,7 @@
#include <linux/uio.h>
#include <linux/backing-dev.h>
#include <linux/buffer_head.h>
+#include <linux/task_io_accounting_ops.h>
#include <linux/dax.h>
#include "internal.h"
@@ -584,3 +585,375 @@ int iomap_fiemap(struct inode *inode, struct fiemap_extent_info *fi,
return 0;
}
EXPORT_SYMBOL_GPL(iomap_fiemap);
+
+/*
+ * Private flags for iomap_dio, must not overlap with the public ones in
+ * iomap.h:
+ */
+#define IOMAP_DIO_WRITE (1 << 30)
+#define IOMAP_DIO_DIRTY (1 << 31)
+
+struct iomap_dio {
+ struct kiocb *iocb;
+ iomap_dio_end_io_t *end_io;
+ loff_t i_size;
+ loff_t size;
+ atomic_t ref;
+ unsigned flags;
+ int error;
+
+ union {
+ /* used during submission and for synchronous completion: */
+ struct {
+ struct iov_iter *iter;
+ struct task_struct *waiter;
+ struct request_queue *last_queue;
+ blk_qc_t cookie;
+ } submit;
+
+ /* used for aio completion: */
+ struct {
+ struct work_struct work;
+ } aio;
+ };
+};
+
+static ssize_t iomap_dio_complete(struct iomap_dio *dio)
+{
+ struct kiocb *iocb = dio->iocb;
+ ssize_t ret;
+
+ if (dio->end_io) {
+ ret = dio->end_io(iocb,
+ dio->error ? dio->error : dio->size,
+ dio->flags);
+ } else {
+ ret = dio->error;
+ }
+
+ if (likely(!ret)) {
+ ret = dio->size;
+ /* check for short read */
+ if (iocb->ki_pos + ret > dio->i_size &&
+ !(dio->flags & IOMAP_DIO_WRITE))
+ ret = dio->i_size - iocb->ki_pos;
+ iocb->ki_pos += ret;
+ }
+
+ inode_dio_end(file_inode(iocb->ki_filp));
+ kfree(dio);
+
+ return ret;
+}
+
+static void iomap_dio_complete_work(struct work_struct *work)
+{
+ struct iomap_dio *dio = container_of(work, struct iomap_dio, aio.work);
+ struct kiocb *iocb = dio->iocb;
+ bool is_write = (dio->flags & IOMAP_DIO_WRITE);
+ ssize_t ret;
+
+ ret = iomap_dio_complete(dio);
+ if (is_write && ret > 0)
+ ret = generic_write_sync(iocb, ret);
+ iocb->ki_complete(iocb, ret, 0);
+}
+
+/*
+ * Set an error in the dio if none is set yet. We have to use cmpxchg
+ * as the submission context and the completion context(s) can race to
+ * update the error.
+ */
+static inline void iomap_dio_set_error(struct iomap_dio *dio, int ret)
+{
+ cmpxchg(&dio->error, 0, ret);
+}
+
+static void iomap_dio_bio_end_io(struct bio *bio)
+{
+ struct iomap_dio *dio = bio->bi_private;
+ bool should_dirty = (dio->flags & IOMAP_DIO_DIRTY);
+
+ if (bio->bi_error)
+ iomap_dio_set_error(dio, bio->bi_error);
+
+ if (atomic_dec_and_test(&dio->ref)) {
+ if (is_sync_kiocb(dio->iocb)) {
+ struct task_struct *waiter = dio->submit.waiter;
+
+ WRITE_ONCE(dio->submit.waiter, NULL);
+ wake_up_process(waiter);
+ } else if (dio->flags & IOMAP_DIO_WRITE) {
+ struct inode *inode = file_inode(dio->iocb->ki_filp);
+
+ INIT_WORK(&dio->aio.work, iomap_dio_complete_work);
+ queue_work(inode->i_sb->s_dio_done_wq, &dio->aio.work);
+ } else {
+ iomap_dio_complete_work(&dio->aio.work);
+ }
+ }
+
+ if (should_dirty) {
+ bio_check_pages_dirty(bio);
+ } else {
+ struct bio_vec *bvec;
+ int i;
+
+ bio_for_each_segment_all(bvec, bio, i)
+ put_page(bvec->bv_page);
+ bio_put(bio);
+ }
+}
+
+static blk_qc_t
+iomap_dio_zero(struct iomap_dio *dio, struct iomap *iomap, loff_t pos,
+ unsigned len)
+{
+ struct page *page = ZERO_PAGE(0);
+ struct bio *bio;
+
+ bio = bio_alloc(GFP_KERNEL, 1);
+ bio->bi_bdev = iomap->bdev;
+ bio->bi_iter.bi_sector =
+ iomap->blkno + ((pos - iomap->offset) >> 9);
+ bio->bi_private = dio;
+ bio->bi_end_io = iomap_dio_bio_end_io;
+
+ get_page(page);
+ if (bio_add_page(bio, page, len, 0) != len)
+ BUG();
+ bio_set_op_attrs(bio, REQ_OP_WRITE, WRITE_ODIRECT);
+
+ atomic_inc(&dio->ref);
+ return submit_bio(bio);
+}
+
+static loff_t
+iomap_dio_actor(struct inode *inode, loff_t pos, loff_t length,
+ void *data, struct iomap *iomap)
+{
+ struct iomap_dio *dio = data;
+ unsigned blkbits = blksize_bits(bdev_logical_block_size(iomap->bdev));
+ unsigned fs_block_size = (1 << inode->i_blkbits), pad;
+ unsigned align = iov_iter_alignment(dio->submit.iter);
+ struct iov_iter iter;
+ struct bio *bio;
+ bool need_zeroout = false;
+ int nr_pages, ret;
+
+ if ((pos | length | align) & ((1 << blkbits) - 1))
+ return -EINVAL;
+
+ switch (iomap->type) {
+ case IOMAP_HOLE:
+ if (WARN_ON_ONCE(dio->flags & IOMAP_DIO_WRITE))
+ return -EIO;
+ /*FALLTHRU*/
+ case IOMAP_UNWRITTEN:
+ if (!(dio->flags & IOMAP_DIO_WRITE)) {
+ iov_iter_zero(length, dio->submit.iter);
+ dio->size += length;
+ return length;
+ }
+ dio->flags |= IOMAP_DIO_UNWRITTEN;
+ need_zeroout = true;
+ break;
+ case IOMAP_MAPPED:
+ if (iomap->flags & IOMAP_F_SHARED)
+ dio->flags |= IOMAP_DIO_COW;
+ if (iomap->flags & IOMAP_F_NEW)
+ need_zeroout = true;
+ break;
+ default:
+ WARN_ON_ONCE(1);
+ return -EIO;
+ }
+
+ /*
+ * Operate on a partial iter trimmed to the extent we were called for.
+ * We'll update the iter in the dio once we're done with this extent.
+ */
+ iter = *dio->submit.iter;
+ iov_iter_truncate(&iter, length);
+
+ nr_pages = iov_iter_npages(&iter, BIO_MAX_PAGES);
+ if (nr_pages <= 0)
+ return nr_pages;
+
+ if (need_zeroout) {
+ /* zero out from the start of the block to the write offset */
+ pad = pos & (fs_block_size - 1);
+ if (pad)
+ iomap_dio_zero(dio, iomap, pos - pad, pad);
+ }
+
+ do {
+ if (dio->error)
+ return 0;
+
+ bio = bio_alloc(GFP_KERNEL, nr_pages);
+ bio->bi_bdev = iomap->bdev;
+ bio->bi_iter.bi_sector =
+ iomap->blkno + ((pos - iomap->offset) >> 9);
+ bio->bi_private = dio;
+ bio->bi_end_io = iomap_dio_bio_end_io;
+
+ ret = bio_iov_iter_get_pages(bio, &iter);
+ if (unlikely(ret)) {
+ bio_put(bio);
+ return ret;
+ }
+
+ if (dio->flags & IOMAP_DIO_WRITE) {
+ bio_set_op_attrs(bio, REQ_OP_WRITE, WRITE_ODIRECT);
+ task_io_account_write(bio->bi_iter.bi_size);
+ } else {
+ bio_set_op_attrs(bio, REQ_OP_READ, 0);
+ if (dio->flags & IOMAP_DIO_DIRTY)
+ bio_set_pages_dirty(bio);
+ }
+
+ dio->size += bio->bi_iter.bi_size;
+ pos += bio->bi_iter.bi_size;
+
+ nr_pages = iov_iter_npages(&iter, BIO_MAX_PAGES);
+
+ atomic_inc(&dio->ref);
+
+ dio->submit.last_queue = bdev_get_queue(iomap->bdev);
+ dio->submit.cookie = submit_bio(bio);
+ } while (nr_pages);
+
+ if (need_zeroout) {
+ /* zero out from the end of the write to the end of the block */
+ pad = pos & (fs_block_size - 1);
+ if (pad)
+ iomap_dio_zero(dio, iomap, pos, fs_block_size - pad);
+ }
+
+ iov_iter_advance(dio->submit.iter, length);
+ return length;
+}
+
+ssize_t
+iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter, struct iomap_ops *ops,
+ iomap_dio_end_io_t end_io)
+{
+ struct address_space *mapping = iocb->ki_filp->f_mapping;
+ struct inode *inode = file_inode(iocb->ki_filp);
+ size_t count = iov_iter_count(iter);
+ loff_t pos = iocb->ki_pos, end = iocb->ki_pos + count - 1, ret = 0;
+ unsigned int flags = IOMAP_DIRECT;
+ struct blk_plug plug;
+ struct iomap_dio *dio;
+
+ lockdep_assert_held(&inode->i_rwsem);
+
+ if (!count)
+ return 0;
+
+ dio = kmalloc(sizeof(*dio), GFP_KERNEL);
+ if (!dio)
+ return -ENOMEM;
+
+ dio->iocb = iocb;
+ atomic_set(&dio->ref, 1);
+ dio->size = 0;
+ dio->i_size = i_size_read(inode);
+ dio->end_io = end_io;
+ dio->error = 0;
+ dio->flags = 0;
+
+ dio->submit.iter = iter;
+ if (is_sync_kiocb(iocb)) {
+ dio->submit.waiter = current;
+ dio->submit.cookie = BLK_QC_T_NONE;
+ dio->submit.last_queue = NULL;
+ }
+
+ if (iov_iter_rw(iter) == READ) {
+ if (pos >= dio->i_size)
+ goto out_free_dio;
+
+ if (iter->type == ITER_IOVEC)
+ dio->flags |= IOMAP_DIO_DIRTY;
+ } else {
+ dio->flags |= IOMAP_DIO_WRITE;
+ flags |= IOMAP_WRITE;
+ }
+
+ if (mapping->nrpages) {
+ ret = filemap_write_and_wait_range(mapping, iocb->ki_pos, end);
+ if (ret)
+ goto out_free_dio;
+
+ ret = invalidate_inode_pages2_range(mapping,
+ iocb->ki_pos >> PAGE_SHIFT, end >> PAGE_SHIFT);
+ WARN_ON_ONCE(ret);
+ ret = 0;
+ }
+
+ inode_dio_begin(inode);
+
+ blk_start_plug(&plug);
+ do {
+ ret = iomap_apply(inode, pos, count, flags, ops, dio,
+ iomap_dio_actor);
+ if (ret <= 0) {
+ /* magic error code to fall back to buffered I/O */
+ if (ret == -ENOTBLK)
+ ret = 0;
+ break;
+ }
+ pos += ret;
+ } while ((count = iov_iter_count(iter)) > 0);
+ blk_finish_plug(&plug);
+
+ if (ret < 0)
+ iomap_dio_set_error(dio, ret);
+
+ if (ret >= 0 && iov_iter_rw(iter) == WRITE && !is_sync_kiocb(iocb) &&
+ !inode->i_sb->s_dio_done_wq) {
+ ret = sb_init_dio_done_wq(inode->i_sb);
+ if (ret < 0)
+ iomap_dio_set_error(dio, ret);
+ }
+
+ if (!atomic_dec_and_test(&dio->ref)) {
+ if (!is_sync_kiocb(iocb))
+ return -EIOCBQUEUED;
+
+ for (;;) {
+ set_current_state(TASK_UNINTERRUPTIBLE);
+ if (!READ_ONCE(dio->submit.waiter))
+ break;
+
+ if (!(iocb->ki_flags & IOCB_HIPRI) ||
+ !dio->submit.last_queue ||
+ !blk_poll(dio->submit.last_queue,
+ dio->submit.cookie))
+ io_schedule();
+ }
+ __set_current_state(TASK_RUNNING);
+ }
+
+ /*
+ * Try again to invalidate clean pages which might have been cached by
+ * non-direct readahead, or faulted in by get_user_pages() if the source
+ * of the write was an mmap'ed region of the file we're writing. Either
+ * one is a pretty crazy thing to do, so we don't support it 100%. If
+ * this invalidation fails, tough, the write still worked...
+ */
+ if (iov_iter_rw(iter) == WRITE && mapping->nrpages) {
+ ret = invalidate_inode_pages2_range(mapping,
+ iocb->ki_pos >> PAGE_SHIFT, end >> PAGE_SHIFT);
+ WARN_ON_ONCE(ret);
+ }
+
+ return iomap_dio_complete(dio);
+
+out_free_dio:
+ kfree(dio);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(iomap_dio_rw);
diff --git a/include/linux/iomap.h b/include/linux/iomap.h
index f185156..a4c94b8 100644
--- a/include/linux/iomap.h
+++ b/include/linux/iomap.h
@@ -50,6 +50,7 @@ struct iomap {
#define IOMAP_ZERO (1 << 1) /* zeroing operation, may skip holes */
#define IOMAP_REPORT (1 << 2) /* report extent status, e.g. FIEMAP */
#define IOMAP_FAULT (1 << 3) /* mapping for page fault */
+#define IOMAP_DIRECT (1 << 4) /* direct I/O */
struct iomap_ops {
/*
@@ -83,4 +84,14 @@ int iomap_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf,
int iomap_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
loff_t start, loff_t len, struct iomap_ops *ops);
+/*
+ * Flags for direct I/O ->end_io:
+ */
+#define IOMAP_DIO_UNWRITTEN (1 << 0) /* covers unwritten extent(s) */
+#define IOMAP_DIO_COW (1 << 1) /* covers COW extent(s) */
+typedef int (iomap_dio_end_io_t)(struct kiocb *iocb, ssize_t ret,
+ unsigned flags);
+ssize_t iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter,
+ struct iomap_ops *ops, iomap_dio_end_io_t end_io);
+
#endif /* LINUX_IOMAP_H */
--
2.1.4
^ permalink raw reply related [flat|nested] 8+ messages in thread* [PATCH 5/5] xfs: use iomap_dio_rw
2016-11-29 17:28 an iomap-based direct I/O implementation V4 Christoph Hellwig
` (3 preceding siblings ...)
2016-11-29 17:28 ` [PATCH 4/5] iomap: implement direct I/O Christoph Hellwig
@ 2016-11-29 17:28 ` Christoph Hellwig
2016-11-29 22:22 ` an iomap-based direct I/O implementation V4 Jens Axboe
2016-11-29 23:18 ` Darrick J. Wong
6 siblings, 0 replies; 8+ messages in thread
From: Christoph Hellwig @ 2016-11-29 17:28 UTC (permalink / raw)
To: linux-xfs; +Cc: axboe, linux-fsdevel
Straight switch over to using iomap for direct I/O - we already have the
non-COW dio path in write_begin for DAX and files with extent size hints,
so nothing to add there. The COW path is ported over from the old
get_blocks version and a bit of a mess, but I have some work in progress
to make it look more like the buffered I/O COW path.
This gets rid of xfs_get_blocks_direct and the last caller of
xfs_get_blocks with the create flag set, so all that code can be removed.
Last but not least I've removed a comment in xfs_filemap_fault that
refers to xfs_get_blocks entirely instead of updating it - while the
reference is correct, the whole DAX fault path looks different than
the non-DAX one, so it seems rather pointless.
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
fs/iomap.c | 2 +-
fs/xfs/xfs_aops.c | 291 ++---------------------------------------------------
fs/xfs/xfs_aops.h | 6 --
fs/xfs/xfs_file.c | 149 +++++++++++----------------
fs/xfs/xfs_iomap.c | 50 +++++++--
5 files changed, 111 insertions(+), 387 deletions(-)
diff --git a/fs/iomap.c b/fs/iomap.c
index 93d36fd..fc24462 100644
--- a/fs/iomap.c
+++ b/fs/iomap.c
@@ -591,7 +591,7 @@ EXPORT_SYMBOL_GPL(iomap_fiemap);
* iomap.h:
*/
#define IOMAP_DIO_WRITE (1 << 30)
-#define IOMAP_DIO_DIRTY (1 << 31)
+#define IOMAP_DIO_DIRTY (1 << 31)
struct iomap_dio {
struct kiocb *iocb;
diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c
index e8f6c2b..265000a 100644
--- a/fs/xfs/xfs_aops.c
+++ b/fs/xfs/xfs_aops.c
@@ -37,11 +37,6 @@
#include <linux/pagevec.h>
#include <linux/writeback.h>
-/* flags for direct write completions */
-#define XFS_DIO_FLAG_UNWRITTEN (1 << 0)
-#define XFS_DIO_FLAG_APPEND (1 << 1)
-#define XFS_DIO_FLAG_COW (1 << 2)
-
/*
* structure owned by writepages passed to individual writepage calls
*/
@@ -1176,45 +1171,6 @@ xfs_vm_releasepage(
}
/*
- * When we map a DIO buffer, we may need to pass flags to
- * xfs_end_io_direct_write to tell it what kind of write IO we are doing.
- *
- * Note that for DIO, an IO to the highest supported file block offset (i.e.
- * 2^63 - 1FSB bytes) will result in the offset + count overflowing a signed 64
- * bit variable. Hence if we see this overflow, we have to assume that the IO is
- * extending the file size. We won't know for sure until IO completion is run
- * and the actual max write offset is communicated to the IO completion
- * routine.
- */
-static void
-xfs_map_direct(
- struct inode *inode,
- struct buffer_head *bh_result,
- struct xfs_bmbt_irec *imap,
- xfs_off_t offset,
- bool is_cow)
-{
- uintptr_t *flags = (uintptr_t *)&bh_result->b_private;
- xfs_off_t size = bh_result->b_size;
-
- trace_xfs_get_blocks_map_direct(XFS_I(inode), offset, size,
- ISUNWRITTEN(imap) ? XFS_IO_UNWRITTEN : is_cow ? XFS_IO_COW :
- XFS_IO_OVERWRITE, imap);
-
- if (ISUNWRITTEN(imap)) {
- *flags |= XFS_DIO_FLAG_UNWRITTEN;
- set_buffer_defer_completion(bh_result);
- } else if (is_cow) {
- *flags |= XFS_DIO_FLAG_COW;
- set_buffer_defer_completion(bh_result);
- }
- if (offset + size > i_size_read(inode) || offset + size < 0) {
- *flags |= XFS_DIO_FLAG_APPEND;
- set_buffer_defer_completion(bh_result);
- }
-}
-
-/*
* If this is O_DIRECT or the mpage code calling tell them how large the mapping
* is, so that we can avoid repeated get_blocks calls.
*
@@ -1254,51 +1210,12 @@ xfs_map_trim_size(
bh_result->b_size = mapping_size;
}
-/* Bounce unaligned directio writes to the page cache. */
static int
-xfs_bounce_unaligned_dio_write(
- struct xfs_inode *ip,
- xfs_fileoff_t offset_fsb,
- struct xfs_bmbt_irec *imap)
-{
- struct xfs_bmbt_irec irec;
- xfs_fileoff_t delta;
- bool shared;
- bool x;
- int error;
-
- irec = *imap;
- if (offset_fsb > irec.br_startoff) {
- delta = offset_fsb - irec.br_startoff;
- irec.br_blockcount -= delta;
- irec.br_startblock += delta;
- irec.br_startoff = offset_fsb;
- }
- error = xfs_reflink_trim_around_shared(ip, &irec, &shared, &x);
- if (error)
- return error;
-
- /*
- * We're here because we're trying to do a directio write to a
- * region that isn't aligned to a filesystem block. If any part
- * of the extent is shared, fall back to buffered mode to handle
- * the RMW. This is done by returning -EREMCHG ("remote addr
- * changed"), which is caught further up the call stack.
- */
- if (shared) {
- trace_xfs_reflink_bounce_dio_write(ip, imap);
- return -EREMCHG;
- }
- return 0;
-}
-
-STATIC int
-__xfs_get_blocks(
+xfs_get_blocks(
struct inode *inode,
sector_t iblock,
struct buffer_head *bh_result,
- int create,
- bool direct)
+ int create)
{
struct xfs_inode *ip = XFS_I(inode);
struct xfs_mount *mp = ip->i_mount;
@@ -1309,10 +1226,8 @@ __xfs_get_blocks(
int nimaps = 1;
xfs_off_t offset;
ssize_t size;
- int new = 0;
- bool is_cow = false;
- BUG_ON(create && !direct);
+ BUG_ON(create);
if (XFS_FORCED_SHUTDOWN(mp))
return -EIO;
@@ -1321,7 +1236,7 @@ __xfs_get_blocks(
ASSERT(bh_result->b_size >= (1 << inode->i_blkbits));
size = bh_result->b_size;
- if (!create && offset >= i_size_read(inode))
+ if (offset >= i_size_read(inode))
return 0;
/*
@@ -1336,73 +1251,12 @@ __xfs_get_blocks(
end_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)offset + size);
offset_fsb = XFS_B_TO_FSBT(mp, offset);
- if (create && direct && xfs_is_reflink_inode(ip)) {
- is_cow = xfs_reflink_find_cow_mapping(ip, offset, &imap);
- ASSERT(!is_cow || !isnullstartblock(imap.br_startblock));
- }
-
- if (!is_cow) {
- error = xfs_bmapi_read(ip, offset_fsb, end_fsb - offset_fsb,
- &imap, &nimaps, XFS_BMAPI_ENTIRE);
- /*
- * Truncate an overwrite extent if there's a pending CoW
- * reservation before the end of this extent. This
- * forces us to come back to get_blocks to take care of
- * the CoW.
- */
- if (create && direct && nimaps &&
- imap.br_startblock != HOLESTARTBLOCK &&
- imap.br_startblock != DELAYSTARTBLOCK &&
- !ISUNWRITTEN(&imap))
- xfs_reflink_trim_irec_to_next_cow(ip, offset_fsb,
- &imap);
- }
+ error = xfs_bmapi_read(ip, offset_fsb, end_fsb - offset_fsb,
+ &imap, &nimaps, XFS_BMAPI_ENTIRE);
if (error)
goto out_unlock;
- /*
- * The only time we can ever safely find delalloc blocks on direct I/O
- * is a dio write to post-eof speculative preallocation. All other
- * scenarios are indicative of a problem or misuse (such as mixing
- * direct and mapped I/O).
- *
- * The file may be unmapped by the time we get here so we cannot
- * reliably fail the I/O based on mapping. Instead, fail the I/O if this
- * is a read or a write within eof. Otherwise, carry on but warn as a
- * precuation if the file happens to be mapped.
- */
- if (direct && imap.br_startblock == DELAYSTARTBLOCK) {
- if (!create || offset < i_size_read(VFS_I(ip))) {
- WARN_ON_ONCE(1);
- error = -EIO;
- goto out_unlock;
- }
- WARN_ON_ONCE(mapping_mapped(VFS_I(ip)->i_mapping));
- }
-
- /* for DAX, we convert unwritten extents directly */
- if (create &&
- (!nimaps ||
- (imap.br_startblock == HOLESTARTBLOCK ||
- imap.br_startblock == DELAYSTARTBLOCK) ||
- (IS_DAX(inode) && ISUNWRITTEN(&imap)))) {
- /*
- * xfs_iomap_write_direct() expects the shared lock. It
- * is unlocked on return.
- */
- if (lockmode == XFS_ILOCK_EXCL)
- xfs_ilock_demote(ip, lockmode);
-
- error = xfs_iomap_write_direct(ip, offset, size,
- &imap, nimaps);
- if (error)
- return error;
- new = 1;
-
- trace_xfs_get_blocks_alloc(ip, offset, size,
- ISUNWRITTEN(&imap) ? XFS_IO_UNWRITTEN
- : XFS_IO_DELALLOC, &imap);
- } else if (nimaps) {
+ if (nimaps) {
trace_xfs_get_blocks_found(ip, offset, size,
ISUNWRITTEN(&imap) ? XFS_IO_UNWRITTEN
: XFS_IO_OVERWRITE, &imap);
@@ -1412,12 +1266,6 @@ __xfs_get_blocks(
goto out_unlock;
}
- if (IS_DAX(inode) && create) {
- ASSERT(!ISUNWRITTEN(&imap));
- /* zeroing is not needed at a higher layer */
- new = 0;
- }
-
/* trim mapping down to size requested */
xfs_map_trim_size(inode, iblock, bh_result, &imap, offset, size);
@@ -1427,43 +1275,14 @@ __xfs_get_blocks(
*/
if (imap.br_startblock != HOLESTARTBLOCK &&
imap.br_startblock != DELAYSTARTBLOCK &&
- (create || !ISUNWRITTEN(&imap))) {
- if (create && direct && !is_cow) {
- error = xfs_bounce_unaligned_dio_write(ip, offset_fsb,
- &imap);
- if (error)
- return error;
- }
-
+ !ISUNWRITTEN(&imap))
xfs_map_buffer(inode, bh_result, &imap, offset);
- if (ISUNWRITTEN(&imap))
- set_buffer_unwritten(bh_result);
- /* direct IO needs special help */
- if (create)
- xfs_map_direct(inode, bh_result, &imap, offset, is_cow);
- }
/*
* If this is a realtime file, data may be on a different device.
* to that pointed to from the buffer_head b_bdev currently.
*/
bh_result->b_bdev = xfs_find_bdev_for_inode(inode);
-
- /*
- * If we previously allocated a block out beyond eof and we are now
- * coming back to use it then we will need to flag it as new even if it
- * has a disk address.
- *
- * With sub-block writes into unwritten extents we also need to mark
- * the buffer as new so that the unwritten parts of the buffer gets
- * correctly zeroed.
- */
- if (create &&
- ((!buffer_mapped(bh_result) && !buffer_uptodate(bh_result)) ||
- (offset >= i_size_read(inode)) ||
- (new || ISUNWRITTEN(&imap))))
- set_buffer_new(bh_result);
-
return 0;
out_unlock:
@@ -1471,100 +1290,6 @@ __xfs_get_blocks(
return error;
}
-int
-xfs_get_blocks(
- struct inode *inode,
- sector_t iblock,
- struct buffer_head *bh_result,
- int create)
-{
- return __xfs_get_blocks(inode, iblock, bh_result, create, false);
-}
-
-int
-xfs_get_blocks_direct(
- struct inode *inode,
- sector_t iblock,
- struct buffer_head *bh_result,
- int create)
-{
- return __xfs_get_blocks(inode, iblock, bh_result, create, true);
-}
-
-/*
- * Complete a direct I/O write request.
- *
- * xfs_map_direct passes us some flags in the private data to tell us what to
- * do. If no flags are set, then the write IO is an overwrite wholly within
- * the existing allocated file size and so there is nothing for us to do.
- *
- * Note that in this case the completion can be called in interrupt context,
- * whereas if we have flags set we will always be called in task context
- * (i.e. from a workqueue).
- */
-int
-xfs_end_io_direct_write(
- struct kiocb *iocb,
- loff_t offset,
- ssize_t size,
- void *private)
-{
- struct inode *inode = file_inode(iocb->ki_filp);
- struct xfs_inode *ip = XFS_I(inode);
- uintptr_t flags = (uintptr_t)private;
- int error = 0;
-
- trace_xfs_end_io_direct_write(ip, offset, size);
-
- if (XFS_FORCED_SHUTDOWN(ip->i_mount))
- return -EIO;
-
- if (size <= 0)
- return size;
-
- /*
- * The flags tell us whether we are doing unwritten extent conversions
- * or an append transaction that updates the on-disk file size. These
- * cases are the only cases where we should *potentially* be needing
- * to update the VFS inode size.
- */
- if (flags == 0) {
- ASSERT(offset + size <= i_size_read(inode));
- return 0;
- }
-
- /*
- * We need to update the in-core inode size here so that we don't end up
- * with the on-disk inode size being outside the in-core inode size. We
- * have no other method of updating EOF for AIO, so always do it here
- * if necessary.
- *
- * We need to lock the test/set EOF update as we can be racing with
- * other IO completions here to update the EOF. Failing to serialise
- * here can result in EOF moving backwards and Bad Things Happen when
- * that occurs.
- */
- spin_lock(&ip->i_flags_lock);
- if (offset + size > i_size_read(inode))
- i_size_write(inode, offset + size);
- spin_unlock(&ip->i_flags_lock);
-
- if (flags & XFS_DIO_FLAG_COW)
- error = xfs_reflink_end_cow(ip, offset, size);
- if (flags & XFS_DIO_FLAG_UNWRITTEN) {
- trace_xfs_end_io_direct_write_unwritten(ip, offset, size);
-
- error = xfs_iomap_write_unwritten(ip, offset, size);
- }
- if (flags & XFS_DIO_FLAG_APPEND) {
- trace_xfs_end_io_direct_write_append(ip, offset, size);
-
- error = xfs_setfilesize(ip, offset, size);
- }
-
- return error;
-}
-
STATIC ssize_t
xfs_vm_direct_IO(
struct kiocb *iocb,
diff --git a/fs/xfs/xfs_aops.h b/fs/xfs/xfs_aops.h
index 34dc00d..cc174ec 100644
--- a/fs/xfs/xfs_aops.h
+++ b/fs/xfs/xfs_aops.h
@@ -55,12 +55,6 @@ struct xfs_ioend {
extern const struct address_space_operations xfs_address_space_operations;
-int xfs_get_blocks(struct inode *inode, sector_t offset,
- struct buffer_head *map_bh, int create);
-int xfs_get_blocks_direct(struct inode *inode, sector_t offset,
- struct buffer_head *map_bh, int create);
-int xfs_end_io_direct_write(struct kiocb *iocb, loff_t offset,
- ssize_t size, void *private);
int xfs_setfilesize(struct xfs_inode *ip, xfs_off_t offset, size_t size);
extern void xfs_count_page_state(struct page *, int *, int *);
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index d054b73..f5effa6 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -210,62 +210,21 @@ xfs_file_dio_aio_read(
struct kiocb *iocb,
struct iov_iter *to)
{
- struct address_space *mapping = iocb->ki_filp->f_mapping;
- struct inode *inode = mapping->host;
- struct xfs_inode *ip = XFS_I(inode);
- loff_t isize = i_size_read(inode);
+ struct xfs_inode *ip = XFS_I(file_inode(iocb->ki_filp));
size_t count = iov_iter_count(to);
- loff_t end = iocb->ki_pos + count - 1;
- struct iov_iter data;
- struct xfs_buftarg *target;
- ssize_t ret = 0;
+ ssize_t ret;
trace_xfs_file_direct_read(ip, count, iocb->ki_pos);
if (!count)
return 0; /* skip atime */
- if (XFS_IS_REALTIME_INODE(ip))
- target = ip->i_mount->m_rtdev_targp;
- else
- target = ip->i_mount->m_ddev_targp;
-
- /* DIO must be aligned to device logical sector size */
- if ((iocb->ki_pos | count) & target->bt_logical_sectormask) {
- if (iocb->ki_pos == isize)
- return 0;
- return -EINVAL;
- }
-
file_accessed(iocb->ki_filp);
xfs_ilock(ip, XFS_IOLOCK_SHARED);
- if (mapping->nrpages) {
- ret = filemap_write_and_wait_range(mapping, iocb->ki_pos, end);
- if (ret)
- goto out_unlock;
-
- /*
- * Invalidate whole pages. This can return an error if we fail
- * to invalidate a page, but this should never happen on XFS.
- * Warn if it does fail.
- */
- ret = invalidate_inode_pages2_range(mapping,
- iocb->ki_pos >> PAGE_SHIFT, end >> PAGE_SHIFT);
- WARN_ON_ONCE(ret);
- ret = 0;
- }
-
- data = *to;
- ret = __blockdev_direct_IO(iocb, inode, target->bt_bdev, &data,
- xfs_get_blocks_direct, NULL, NULL, 0);
- if (ret >= 0) {
- iocb->ki_pos += ret;
- iov_iter_advance(to, ret);
- }
-
-out_unlock:
+ ret = iomap_dio_rw(iocb, to, &xfs_iomap_ops, NULL);
xfs_iunlock(ip, XFS_IOLOCK_SHARED);
+
return ret;
}
@@ -465,6 +424,58 @@ xfs_file_aio_write_checks(
return 0;
}
+static int
+xfs_dio_write_end_io(
+ struct kiocb *iocb,
+ ssize_t size,
+ unsigned flags)
+{
+ struct inode *inode = file_inode(iocb->ki_filp);
+ struct xfs_inode *ip = XFS_I(inode);
+ loff_t offset = iocb->ki_pos;
+ bool update_size = false;
+ int error = 0;
+
+ trace_xfs_end_io_direct_write(ip, offset, size);
+
+ if (XFS_FORCED_SHUTDOWN(ip->i_mount))
+ return -EIO;
+
+ if (size <= 0)
+ return size;
+
+ /*
+ * We need to update the in-core inode size here so that we don't end up
+ * with the on-disk inode size being outside the in-core inode size. We
+ * have no other method of updating EOF for AIO, so always do it here
+ * if necessary.
+ *
+ * We need to lock the test/set EOF update as we can be racing with
+ * other IO completions here to update the EOF. Failing to serialise
+ * here can result in EOF moving backwards and Bad Things Happen when
+ * that occurs.
+ */
+ spin_lock(&ip->i_flags_lock);
+ if (offset + size > i_size_read(inode)) {
+ i_size_write(inode, offset + size);
+ update_size = true;
+ }
+ spin_unlock(&ip->i_flags_lock);
+
+ if (flags & IOMAP_DIO_COW) {
+ error = xfs_reflink_end_cow(ip, offset, size);
+ if (error)
+ return error;
+ }
+
+ if (flags & IOMAP_DIO_UNWRITTEN)
+ error = xfs_iomap_write_unwritten(ip, offset, size);
+ else if (update_size)
+ error = xfs_setfilesize(ip, offset, size);
+
+ return error;
+}
+
/*
* xfs_file_dio_aio_write - handle direct IO writes
*
@@ -504,9 +515,7 @@ xfs_file_dio_aio_write(
int unaligned_io = 0;
int iolock;
size_t count = iov_iter_count(from);
- loff_t end;
- struct iov_iter data;
- struct xfs_buftarg *target = XFS_IS_REALTIME_INODE(ip) ?
+ struct xfs_buftarg *target = XFS_IS_REALTIME_INODE(ip) ?
mp->m_rtdev_targp : mp->m_ddev_targp;
/* DIO must be aligned to device logical sector size */
@@ -534,23 +543,6 @@ xfs_file_dio_aio_write(
if (ret)
goto out;
count = iov_iter_count(from);
- end = iocb->ki_pos + count - 1;
-
- if (mapping->nrpages) {
- ret = filemap_write_and_wait_range(mapping, iocb->ki_pos, end);
- if (ret)
- goto out;
-
- /*
- * Invalidate whole pages. This can return an error if we fail
- * to invalidate a page, but this should never happen on XFS.
- * Warn if it does fail.
- */
- ret = invalidate_inode_pages2_range(mapping,
- iocb->ki_pos >> PAGE_SHIFT, end >> PAGE_SHIFT);
- WARN_ON_ONCE(ret);
- ret = 0;
- }
/*
* If we are doing unaligned IO, wait for all other IO to drain,
@@ -573,22 +565,7 @@ xfs_file_dio_aio_write(
goto out;
}
- data = *from;
- ret = __blockdev_direct_IO(iocb, inode, target->bt_bdev, &data,
- xfs_get_blocks_direct, xfs_end_io_direct_write,
- NULL, DIO_ASYNC_EXTEND);
-
- /* see generic_file_direct_write() for why this is necessary */
- if (mapping->nrpages) {
- invalidate_inode_pages2_range(mapping,
- iocb->ki_pos >> PAGE_SHIFT,
- end >> PAGE_SHIFT);
- }
-
- if (ret > 0) {
- iocb->ki_pos += ret;
- iov_iter_advance(from, ret);
- }
+ ret = iomap_dio_rw(iocb, from, &xfs_iomap_ops, xfs_dio_write_end_io);
out:
xfs_iunlock(ip, iolock);
@@ -1468,15 +1445,9 @@ xfs_filemap_fault(
return xfs_filemap_page_mkwrite(vma, vmf);
xfs_ilock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
- if (IS_DAX(inode)) {
- /*
- * we do not want to trigger unwritten extent conversion on read
- * faults - that is unnecessary overhead and would also require
- * changes to xfs_get_blocks_direct() to map unwritten extent
- * ioend for conversion on read-only mappings.
- */
+ if (IS_DAX(inode))
ret = dax_iomap_fault(vma, vmf, &xfs_iomap_ops);
- } else
+ else
ret = filemap_fault(vma, vmf);
xfs_iunlock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c
index 15a83813..0d14742 100644
--- a/fs/xfs/xfs_iomap.c
+++ b/fs/xfs/xfs_iomap.c
@@ -950,6 +950,19 @@ static inline bool imap_needs_alloc(struct inode *inode,
(IS_DAX(inode) && ISUNWRITTEN(imap));
}
+static inline bool need_excl_ilock(struct xfs_inode *ip, unsigned flags)
+{
+ /*
+ * COW writes will allocate delalloc space, so we need to make sure
+ * to take the lock exclusively here.
+ */
+ if (xfs_is_reflink_inode(ip) && (flags & (IOMAP_WRITE | IOMAP_ZERO)))
+ return true;
+ if ((flags & IOMAP_DIRECT) && (flags & IOMAP_WRITE))
+ return true;
+ return false;
+}
+
static int
xfs_file_iomap_begin(
struct inode *inode,
@@ -969,18 +982,14 @@ xfs_file_iomap_begin(
if (XFS_FORCED_SHUTDOWN(mp))
return -EIO;
- if ((flags & IOMAP_WRITE) && !IS_DAX(inode) &&
- !xfs_get_extsz_hint(ip)) {
+ if (((flags & (IOMAP_WRITE | IOMAP_DIRECT)) == IOMAP_WRITE) &&
+ !IS_DAX(inode) && !xfs_get_extsz_hint(ip)) {
/* Reserve delalloc blocks for regular writeback. */
return xfs_file_iomap_begin_delay(inode, offset, length, flags,
iomap);
}
- /*
- * COW writes will allocate delalloc space, so we need to make sure
- * to take the lock exclusively here.
- */
- if ((flags & (IOMAP_WRITE | IOMAP_ZERO)) && xfs_is_reflink_inode(ip)) {
+ if (need_excl_ilock(ip, flags)) {
lockmode = XFS_ILOCK_EXCL;
xfs_ilock(ip, XFS_ILOCK_EXCL);
} else {
@@ -993,17 +1002,41 @@ xfs_file_iomap_begin(
offset_fsb = XFS_B_TO_FSBT(mp, offset);
end_fsb = XFS_B_TO_FSB(mp, offset + length);
+ if (xfs_is_reflink_inode(ip) &&
+ (flags & IOMAP_WRITE) && (flags & IOMAP_DIRECT)) {
+ shared = xfs_reflink_find_cow_mapping(ip, offset, &imap);
+ if (shared) {
+ xfs_iunlock(ip, lockmode);
+ goto alloc_done;
+ }
+ ASSERT(!isnullstartblock(imap.br_startblock));
+ }
+
error = xfs_bmapi_read(ip, offset_fsb, end_fsb - offset_fsb, &imap,
&nimaps, 0);
if (error)
goto out_unlock;
- if (flags & IOMAP_REPORT) {
+ if ((flags & IOMAP_REPORT) ||
+ (xfs_is_reflink_inode(ip) &&
+ (flags & IOMAP_WRITE) && (flags & IOMAP_DIRECT))) {
/* Trim the mapping to the nearest shared extent boundary. */
error = xfs_reflink_trim_around_shared(ip, &imap, &shared,
&trimmed);
if (error)
goto out_unlock;
+
+ /*
+ * We're here because we're trying to do a directio write to a
+ * region that isn't aligned to a filesystem block. If the
+ * extent is shared, fall back to buffered mode to handle the
+ * RMW.
+ */
+ if (!(flags & IOMAP_REPORT) && shared) {
+ trace_xfs_reflink_bounce_dio_write(ip, &imap);
+ error = -EREMCHG;
+ goto out_unlock;
+ }
}
if ((flags & (IOMAP_WRITE | IOMAP_ZERO)) && xfs_is_reflink_inode(ip)) {
@@ -1038,6 +1071,7 @@ xfs_file_iomap_begin(
if (error)
return error;
+alloc_done:
iomap->flags = IOMAP_F_NEW;
trace_xfs_iomap_alloc(ip, offset, length, 0, &imap);
} else {
--
2.1.4
^ permalink raw reply related [flat|nested] 8+ messages in thread* Re: an iomap-based direct I/O implementation V4
2016-11-29 17:28 an iomap-based direct I/O implementation V4 Christoph Hellwig
` (4 preceding siblings ...)
2016-11-29 17:28 ` [PATCH 5/5] xfs: use iomap_dio_rw Christoph Hellwig
@ 2016-11-29 22:22 ` Jens Axboe
2016-11-29 23:18 ` Darrick J. Wong
6 siblings, 0 replies; 8+ messages in thread
From: Jens Axboe @ 2016-11-29 22:22 UTC (permalink / raw)
To: Christoph Hellwig, linux-xfs; +Cc: linux-fsdevel
On 11/29/2016 10:28 AM, Christoph Hellwig wrote:
> Hi all,
>
> this series adds a new direct I/O implementation based on the iomap
> interface, and switches XFS to use it.
>
> The first two patches are a resend of my earlier series to remove the
> XFS iolock. They are needed for the lockdep assert in the new iomap
> code.
>
> The rest implements a new iomap_dio_rw direct I/O implementation and
> switches XFS to use it.
>
> It requires a patch from the block tree which we'll need to cherry-pick
> into the XFS tree to avoid pulling in the whole block tree:
>
> 9cd56d91 ("block: add bio_iov_iter_get_pages()")
>
> To make everyones lifer easie I also have a git tree that includes this
> cherry pick:
>
> git://git.infradead.org/users/hch/vfs.git iomap-dio.4
>
> Note that with this patch I see somewhat increased failure rates on
> generic/209. This is not because of any locking or invalidation changes
> in this series, but just because it's always been fundamentally race,
> and the new direct I/O code is a lot faster, which causes the direct
> writes in this test to race significantly more often with readahead.
Ran some testing here, and it seems to perform well. Lower CPU
utilization, or increased performance in the cases where we are maxing
out the CPUs.
You can add my Tested-by to the series.
--
Jens Axboe
^ permalink raw reply [flat|nested] 8+ messages in thread* Re: an iomap-based direct I/O implementation V4
2016-11-29 17:28 an iomap-based direct I/O implementation V4 Christoph Hellwig
` (5 preceding siblings ...)
2016-11-29 22:22 ` an iomap-based direct I/O implementation V4 Jens Axboe
@ 2016-11-29 23:18 ` Darrick J. Wong
6 siblings, 0 replies; 8+ messages in thread
From: Darrick J. Wong @ 2016-11-29 23:18 UTC (permalink / raw)
To: Christoph Hellwig; +Cc: linux-xfs, axboe, linux-fsdevel
On Tue, Nov 29, 2016 at 06:28:11PM +0100, Christoph Hellwig wrote:
> Hi all,
>
> this series adds a new direct I/O implementation based on the iomap
> interface, and switches XFS to use it.
>
> The first two patches are a resend of my earlier series to remove the
> XFS iolock. They are needed for the lockdep assert in the new iomap
> code.
>
> The rest implements a new iomap_dio_rw direct I/O implementation and
> switches XFS to use it.
>
> It requires a patch from the block tree which we'll need to cherry-pick
> into the XFS tree to avoid pulling in the whole block tree:
>
> 9cd56d91 ("block: add bio_iov_iter_get_pages()")
>
> To make everyones lifer easie I also have a git tree that includes this
> cherry pick:
>
> git://git.infradead.org/users/hch/vfs.git iomap-dio.4
>
> Note that with this patch I see somewhat increased failure rates on
> generic/209. This is not because of any locking or invalidation changes
> in this series, but just because it's always been fundamentally race,
> and the new direct I/O code is a lot faster, which causes the direct
> writes in this test to race significantly more often with readahead.
I looked through the patches and didn't have any questions, so:
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
--D
>
>
> Changes since V3:
> - untangle from the block tree
>
> Changes since V2:
> - added a few comments to unconfuse reviewers
> - added a iomap_dio_set_error helper
> - dropped support for not filling holes on writes
> - pulled in a more recent block tree (blk_poll -> blk_mq_poll)
>
> Changes since V1:
> - dropped the bio_iov_iter_get_pages patch, now merged in the block tree
> - rebased on top of a merge of the XFS tree with the block tree
> - stopped using WRITE_ODIRECT which has been removed in the block tree
> --
> To unsubscribe from this list: send the line "unsubscribe linux-xfs" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
^ permalink raw reply [flat|nested] 8+ messages in thread