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Date: Thu, 15 Jul 2021 15:40:18 +0200
From: Jan Kara <jack@...e.cz>
To: <linux-fsdevel@...r.kernel.org>
Cc: <linux-ext4@...r.kernel.org>,
Christoph Hellwig <hch@...radead.org>,
"Darrick J. Wong" <djwong@...nel.org>, Ted Tso <tytso@....edu>,
Dave Chinner <david@...morbit.com>,
Matthew Wilcox <willy@...radead.org>, <linux-mm@...ck.org>,
<linux-xfs@...r.kernel.org>,
linux-f2fs-devel@...ts.sourceforge.net, linux-cifs@...r.kernel.org,
ceph-devel@...r.kernel.org, Jan Kara <jack@...e.cz>,
Christoph Hellwig <hch@....de>
Subject: [PATCH 08/14] xfs: Convert to use invalidate_lock
Use invalidate_lock instead of XFS internal i_mmap_lock. The intended
purpose of invalidate_lock is exactly the same. Note that the locking in
__xfs_filemap_fault() slightly changes as filemap_fault() already takes
invalidate_lock.
Reviewed-by: Christoph Hellwig <hch@....de>
Reviewed-by: Darrick J. Wong <djwong@...nel.org>
CC: <linux-xfs@...r.kernel.org>
CC: "Darrick J. Wong" <djwong@...nel.org>
Signed-off-by: Jan Kara <jack@...e.cz>
---
fs/xfs/xfs_file.c | 13 +++++++-----
fs/xfs/xfs_inode.c | 50 ++++++++++++++++++++++++----------------------
fs/xfs/xfs_inode.h | 1 -
fs/xfs/xfs_super.c | 2 --
4 files changed, 34 insertions(+), 32 deletions(-)
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index cc3cfb12df53..3dfbdcdb0d1c 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -1302,7 +1302,7 @@ xfs_file_llseek(
*
* mmap_lock (MM)
* sb_start_pagefault(vfs, freeze)
- * i_mmaplock (XFS - truncate serialisation)
+ * invalidate_lock (vfs/XFS_MMAPLOCK - truncate serialisation)
* page_lock (MM)
* i_lock (XFS - extent map serialisation)
*/
@@ -1323,24 +1323,27 @@ __xfs_filemap_fault(
file_update_time(vmf->vma->vm_file);
}
- xfs_ilock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
if (IS_DAX(inode)) {
pfn_t pfn;
+ xfs_ilock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
ret = dax_iomap_fault(vmf, pe_size, &pfn, NULL,
(write_fault && !vmf->cow_page) ?
&xfs_direct_write_iomap_ops :
&xfs_read_iomap_ops);
if (ret & VM_FAULT_NEEDDSYNC)
ret = dax_finish_sync_fault(vmf, pe_size, pfn);
+ xfs_iunlock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
} else {
- if (write_fault)
+ if (write_fault) {
+ xfs_ilock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
ret = iomap_page_mkwrite(vmf,
&xfs_buffered_write_iomap_ops);
- else
+ xfs_iunlock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
+ } else {
ret = filemap_fault(vmf);
+ }
}
- xfs_iunlock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
if (write_fault)
sb_end_pagefault(inode->i_sb);
diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
index 359e2cd44ad7..d6a8ac76b45d 100644
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c
@@ -132,7 +132,7 @@ xfs_ilock_attr_map_shared(
/*
* 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
+ * multi-reader locks: invalidate_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,
@@ -140,23 +140,23 @@ xfs_ilock_attr_map_shared(
*
* Basic locking order:
*
- * i_rwsem -> i_mmap_lock -> page_lock -> i_ilock
+ * i_rwsem -> invalidate_lock -> page_lock -> i_ilock
*
* mmap_lock locking order:
*
* i_rwsem -> page lock -> mmap_lock
- * mmap_lock -> i_mmap_lock -> page_lock
+ * mmap_lock -> invalidate_lock -> page_lock
*
* The difference in mmap_lock 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_lock
- * in get_user_pages() to map the user pages into the kernel address space for
- * direct IO. Similarly the i_rwsem cannot be taken inside a page fault because
- * page faults already hold the mmap_lock.
+ * invalidate_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_lock in get_user_pages() to map the user pages into the kernel address
+ * space for direct IO. Similarly the i_rwsem cannot be taken inside a page
+ * fault because page faults already hold the mmap_lock.
*
* Hence to serialise fully against both syscall and mmap based IO, we need to
- * 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
+ * take both the i_rwsem and the invalidate_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).
*/
@@ -188,10 +188,13 @@ xfs_ilock(
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_MMAPLOCK_EXCL) {
+ down_write_nested(&VFS_I(ip)->i_mapping->invalidate_lock,
+ XFS_MMAPLOCK_DEP(lock_flags));
+ } else if (lock_flags & XFS_MMAPLOCK_SHARED) {
+ down_read_nested(&VFS_I(ip)->i_mapping->invalidate_lock,
+ XFS_MMAPLOCK_DEP(lock_flags));
+ }
if (lock_flags & XFS_ILOCK_EXCL)
mrupdate_nested(&ip->i_lock, XFS_ILOCK_DEP(lock_flags));
@@ -240,10 +243,10 @@ xfs_ilock_nowait(
}
if (lock_flags & XFS_MMAPLOCK_EXCL) {
- if (!mrtryupdate(&ip->i_mmaplock))
+ if (!down_write_trylock(&VFS_I(ip)->i_mapping->invalidate_lock))
goto out_undo_iolock;
} else if (lock_flags & XFS_MMAPLOCK_SHARED) {
- if (!mrtryaccess(&ip->i_mmaplock))
+ if (!down_read_trylock(&VFS_I(ip)->i_mapping->invalidate_lock))
goto out_undo_iolock;
}
@@ -258,9 +261,9 @@ xfs_ilock_nowait(
out_undo_mmaplock:
if (lock_flags & XFS_MMAPLOCK_EXCL)
- mrunlock_excl(&ip->i_mmaplock);
+ up_write(&VFS_I(ip)->i_mapping->invalidate_lock);
else if (lock_flags & XFS_MMAPLOCK_SHARED)
- mrunlock_shared(&ip->i_mmaplock);
+ up_read(&VFS_I(ip)->i_mapping->invalidate_lock);
out_undo_iolock:
if (lock_flags & XFS_IOLOCK_EXCL)
up_write(&VFS_I(ip)->i_rwsem);
@@ -307,9 +310,9 @@ xfs_iunlock(
up_read(&VFS_I(ip)->i_rwsem);
if (lock_flags & XFS_MMAPLOCK_EXCL)
- mrunlock_excl(&ip->i_mmaplock);
+ up_write(&VFS_I(ip)->i_mapping->invalidate_lock);
else if (lock_flags & XFS_MMAPLOCK_SHARED)
- mrunlock_shared(&ip->i_mmaplock);
+ up_read(&VFS_I(ip)->i_mapping->invalidate_lock);
if (lock_flags & XFS_ILOCK_EXCL)
mrunlock_excl(&ip->i_lock);
@@ -335,7 +338,7 @@ xfs_ilock_demote(
if (lock_flags & XFS_ILOCK_EXCL)
mrdemote(&ip->i_lock);
if (lock_flags & XFS_MMAPLOCK_EXCL)
- mrdemote(&ip->i_mmaplock);
+ downgrade_write(&VFS_I(ip)->i_mapping->invalidate_lock);
if (lock_flags & XFS_IOLOCK_EXCL)
downgrade_write(&VFS_I(ip)->i_rwsem);
@@ -375,9 +378,8 @@ xfs_isilocked(
}
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);
+ return __xfs_rwsem_islocked(&VFS_I(ip)->i_rwsem,
+ (lock_flags & XFS_IOLOCK_SHARED));
}
if (lock_flags & (XFS_IOLOCK_EXCL | XFS_IOLOCK_SHARED)) {
diff --git a/fs/xfs/xfs_inode.h b/fs/xfs/xfs_inode.h
index 4b5202ae8ebb..e0ae905554e2 100644
--- a/fs/xfs/xfs_inode.h
+++ b/fs/xfs/xfs_inode.h
@@ -40,7 +40,6 @@ 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_mmaplock; /* inode mmap IO lock */
atomic_t i_pincount; /* inode pin count */
/*
diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index 2c9e26a44546..102cbd606633 100644
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c
@@ -709,8 +709,6 @@ 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);
}
--
2.26.2
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