mmap locking API: convert mmap_sem comments

Convert comments that reference mmap_sem to reference mmap_lock instead.

[akpm@linux-foundation.org: fix up linux-next leftovers]
[akpm@linux-foundation.org: s/lockaphore/lock/, per Vlastimil]
[akpm@linux-foundation.org: more linux-next fixups, per Michel]

Signed-off-by: Michel Lespinasse <walken@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Laurent Dufour <ldufour@linux.ibm.com>
Cc: Liam Howlett <Liam.Howlett@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ying Han <yinghan@google.com>
Link: http://lkml.kernel.org/r/20200520052908.204642-13-walken@google.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

11 files changed, 34 insertions, 34 deletions

diff --git a/fs/coredump.c b/fs/coredump.c
index 9fde263af452..7237f07ff6be 100644
--- a/fs/coredump.c
+++ b/fs/coredump.c
@@ -393,7 +393,7 @@ static int zap_threads(struct task_struct *tsk, struct mm_struct *mm,
 	 *	of ->siglock provides a memory barrier.
 	 *
 	 * do_exit:
-	 *	The caller holds mm->mmap_sem. This means that the task which
+	 *	The caller holds mm->mmap_lock. This means that the task which
 	 *	uses this mm can't pass exit_mm(), so it can't exit or clear
 	 *	its ->mm.
 	 *
@@ -401,7 +401,7 @@ static int zap_threads(struct task_struct *tsk, struct mm_struct *mm,
 	 *	It does list_replace_rcu(&leader->tasks, &current->tasks),
 	 *	we must see either old or new leader, this does not matter.
 	 *	However, it can change p->sighand, so lock_task_sighand(p)
-	 *	must be used. Since p->mm != NULL and we hold ->mmap_sem
+	 *	must be used. Since p->mm != NULL and we hold ->mmap_lock
 	 *	it can't fail.
 	 *
 	 *	Note also that "g" can be the old leader with ->mm == NULL
diff --git a/fs/exec.c b/fs/exec.c
index 105b91d191eb..e6e8a9a70327 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -1091,7 +1091,7 @@ static int exec_mmap(struct mm_struct *mm)
 		/*
 		 * Make sure that if there is a core dump in progress
 		 * for the old mm, we get out and die instead of going
-		 * through with the exec.  We must hold mmap_sem around
+		 * through with the exec.  We must hold mmap_lock around
 		 * checking core_state and changing tsk->mm.
 		 */
 		mmap_read_lock(old_mm);
diff --git a/fs/ext2/file.c b/fs/ext2/file.c
index b4de9a0f170d..60378ddf1424 100644
--- a/fs/ext2/file.c
+++ b/fs/ext2/file.c
@@ -79,7 +79,7 @@ out_unlock:
 /*
  * The lock ordering for ext2 DAX fault paths is:
  *
- * mmap_sem (MM)
+ * mmap_lock (MM)
  *   sb_start_pagefault (vfs, freeze)
  *     ext2_inode_info->dax_sem
  *       address_space->i_mmap_rwsem or page_lock (mutually exclusive in DAX)
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index a29e8ea1a7ab..c668f6b42374 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -93,11 +93,11 @@ static struct inode *ext4_get_journal_inode(struct super_block *sb,
  * i_mmap_rwsem (inode->i_mmap_rwsem)!
  *
  * page fault path:
- * mmap_sem -> sb_start_pagefault -> i_mmap_sem (r) -> transaction start ->
+ * mmap_lock -> sb_start_pagefault -> i_mmap_sem (r) -> transaction start ->
  *   page lock -> i_data_sem (rw)
  *
  * buffered write path:
- * sb_start_write -> i_mutex -> mmap_sem
+ * sb_start_write -> i_mutex -> mmap_lock
  * sb_start_write -> i_mutex -> transaction start -> page lock ->
  *   i_data_sem (rw)
  *
@@ -107,7 +107,7 @@ static struct inode *ext4_get_journal_inode(struct super_block *sb,
  *   i_data_sem (rw)
  *
  * direct IO:
- * sb_start_write -> i_mutex -> mmap_sem
+ * sb_start_write -> i_mutex -> mmap_lock
  * sb_start_write -> i_mutex -> transaction start -> i_data_sem (rw)
  *
  * writepages:
diff --git a/fs/kernfs/file.c b/fs/kernfs/file.c
index fd6ddfe4cd94..06b342d8462b 100644
--- a/fs/kernfs/file.c
+++ b/fs/kernfs/file.c
@@ -652,9 +652,9 @@ static int kernfs_fop_open(struct inode *inode, struct file *file)
 	 * The following is done to give a different lockdep key to
 	 * @of->mutex for files which implement mmap.  This is a rather
 	 * crude way to avoid false positive lockdep warning around
-	 * mm->mmap_sem - mmap nests @of->mutex under mm->mmap_sem and
+	 * mm->mmap_lock - mmap nests @of->mutex under mm->mmap_lock and
 	 * reading /sys/block/sda/trace/act_mask grabs sr_mutex, under
-	 * which mm->mmap_sem nests, while holding @of->mutex.  As each
+	 * which mm->mmap_lock nests, while holding @of->mutex.  As each
 	 * open file has a separate mutex, it's okay as long as those don't
 	 * happen on the same file.  At this point, we can't easily give
 	 * each file a separate locking class.  Let's differentiate on
diff --git a/fs/proc/base.c b/fs/proc/base.c
index 4f0d6f40b8f1..d86c0afc8a85 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -2333,11 +2333,11 @@ proc_map_files_readdir(struct file *file, struct dir_context *ctx)
 	/*
 	 * We need two passes here:
 	 *
-	 *  1) Collect vmas of mapped files with mmap_sem taken
-	 *  2) Release mmap_sem and instantiate entries
+	 *  1) Collect vmas of mapped files with mmap_lock taken
+	 *  2) Release mmap_lock and instantiate entries
 	 *
 	 * otherwise we get lockdep complained, since filldir()
-	 * routine might require mmap_sem taken in might_fault().
+	 * routine might require mmap_lock taken in might_fault().
 	 */
 
 	for (vma = mm->mmap, pos = 2; vma; vma = vma->vm_next) {
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 81b985476c1d..dbda4499a859 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -593,7 +593,7 @@ static int smaps_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
 	if (pmd_trans_unstable(pmd))
 		goto out;
 	/*
-	 * The mmap_sem held all the way back in m_start() is what
+	 * The mmap_lock held all the way back in m_start() is what
 	 * keeps khugepaged out of here and from collapsing things
 	 * in here.
 	 */
@@ -752,7 +752,7 @@ static void smap_gather_stats(struct vm_area_struct *vma,
 		}
 	}
 #endif
-	/* mmap_sem is held in m_start */
+	/* mmap_lock is held in m_start */
 	walk_page_vma(vma, &smaps_walk_ops, mss);
 }
 
@@ -1827,7 +1827,7 @@ static int show_numa_map(struct seq_file *m, void *v)
 	if (is_vm_hugetlb_page(vma))
 		seq_puts(m, " huge");
 
-	/* mmap_sem is held by m_start */
+	/* mmap_lock is held by m_start */
 	walk_page_vma(vma, &show_numa_ops, md);
 
 	if (!md->pages)
diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c
index 3a63d75ed2fd..52de29000c7e 100644
--- a/fs/userfaultfd.c
+++ b/fs/userfaultfd.c
@@ -369,13 +369,13 @@ static inline bool userfaultfd_signal_pending(unsigned int flags)
  * FAULT_FLAG_KILLABLE are not straightforward. The "Caution"
  * recommendation in __lock_page_or_retry is not an understatement.
  *
- * If FAULT_FLAG_ALLOW_RETRY is set, the mmap_sem must be released
+ * If FAULT_FLAG_ALLOW_RETRY is set, the mmap_lock must be released
  * before returning VM_FAULT_RETRY only if FAULT_FLAG_RETRY_NOWAIT is
  * not set.
  *
  * If FAULT_FLAG_ALLOW_RETRY is set but FAULT_FLAG_KILLABLE is not
  * set, VM_FAULT_RETRY can still be returned if and only if there are
- * fatal_signal_pending()s, and the mmap_sem must be released before
+ * fatal_signal_pending()s, and the mmap_lock must be released before
  * returning it.
  */
 vm_fault_t handle_userfault(struct vm_fault *vmf, unsigned long reason)
@@ -396,14 +396,14 @@ vm_fault_t handle_userfault(struct vm_fault *vmf, unsigned long reason)
 	 * FOLL_DUMP case, anon memory also checks for FOLL_DUMP with
 	 * the no_page_table() helper in follow_page_mask(), but the
 	 * shmem_vm_ops->fault method is invoked even during
-	 * coredumping without mmap_sem and it ends up here.
+	 * coredumping without mmap_lock and it ends up here.
 	 */
 	if (current->flags & (PF_EXITING|PF_DUMPCORE))
 		goto out;
 
 	/*
-	 * Coredumping runs without mmap_sem so we can only check that
-	 * the mmap_sem is held, if PF_DUMPCORE was not set.
+	 * Coredumping runs without mmap_lock so we can only check that
+	 * the mmap_lock is held, if PF_DUMPCORE was not set.
 	 */
 	mmap_assert_locked(mm);
 
@@ -422,7 +422,7 @@ vm_fault_t handle_userfault(struct vm_fault *vmf, unsigned long reason)
 	/*
 	 * If it's already released don't get it. This avoids to loop
 	 * in __get_user_pages if userfaultfd_release waits on the
-	 * caller of handle_userfault to release the mmap_sem.
+	 * caller of handle_userfault to release the mmap_lock.
 	 */
 	if (unlikely(READ_ONCE(ctx->released))) {
 		/*
@@ -481,7 +481,7 @@ vm_fault_t handle_userfault(struct vm_fault *vmf, unsigned long reason)
 	if (vmf->flags & FAULT_FLAG_RETRY_NOWAIT)
 		goto out;
 
-	/* take the reference before dropping the mmap_sem */
+	/* take the reference before dropping the mmap_lock */
 	userfaultfd_ctx_get(ctx);
 
 	init_waitqueue_func_entry(&uwq.wq, userfaultfd_wake_function);
@@ -890,9 +890,9 @@ static int userfaultfd_release(struct inode *inode, struct file *file)
 	 * Flush page faults out of all CPUs. NOTE: all page faults
 	 * must be retried without returning VM_FAULT_SIGBUS if
 	 * userfaultfd_ctx_get() succeeds but vma->vma_userfault_ctx
-	 * changes while handle_userfault released the mmap_sem. So
+	 * changes while handle_userfault released the mmap_lock. So
 	 * it's critical that released is set to true (above), before
-	 * taking the mmap_sem for writing.
+	 * taking the mmap_lock for writing.
 	 */
 	mmap_write_lock(mm);
 	still_valid = mmget_still_valid(mm);
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index 403c90309a8f..00db81eac80d 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -1173,7 +1173,7 @@ xfs_file_llseek(
  * Locking for serialisation of IO during page faults. This results in a lock
  * ordering of:
  *
- * mmap_sem (MM)
+ * mmap_lock (MM)
  *   sb_start_pagefault(vfs, freeze)
  *     i_mmaplock (XFS - truncate serialisation)
  *       page_lock (MM)
diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
index 64f5f9a440ae..4c91fb25ec66 100644
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c
@@ -145,17 +145,17 @@ xfs_ilock_attr_map_shared(
  *
  * i_rwsem -> i_mmap_lock -> page_lock -> i_ilock
  *
- * mmap_sem locking order:
+ * mmap_lock locking order:
  *
- * i_rwsem -> page lock -> mmap_sem
- * mmap_sem -> i_mmap_lock -> page_lock
+ * i_rwsem -> page lock -> mmap_lock
+ * mmap_lock -> i_mmap_lock -> page_lock
  *
- * The difference in mmap_sem locking order mean that we cannot hold the
+ * 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_sem
+ * 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_sem.
+ * 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
@@ -1630,7 +1630,7 @@ xfs_release(
 			return 0;
 		/*
 		 * If we can't get the iolock just skip truncating the blocks
-		 * past EOF because we could deadlock with the mmap_sem
+		 * past EOF because we could deadlock with the mmap_lock
 		 * otherwise. We'll get another chance to drop them once the
 		 * last reference to the inode is dropped, so we'll never leak
 		 * blocks permanently.
diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c
index 202b2c0a9e9d..80a13c8561d8 100644
--- a/fs/xfs/xfs_iops.c
+++ b/fs/xfs/xfs_iops.c
@@ -28,11 +28,11 @@
 #include <linux/fiemap.h>
 
 /*
- * Directories have different lock order w.r.t. mmap_sem compared to regular
+ * Directories have different lock order w.r.t. mmap_lock compared to regular
  * files. This is due to readdir potentially triggering page faults on a user
  * buffer inside filldir(), and this happens with the ilock on the directory
  * held. For regular files, the lock order is the other way around - the
- * mmap_sem is taken during the page fault, and then we lock the ilock to do
+ * mmap_lock is taken during the page fault, and then we lock the ilock to do
  * block mapping. Hence we need a different class for the directory ilock so
  * that lockdep can tell them apart.
  */