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>
diff --git a/fs/coredump.c b/fs/coredump.c
index 9fde263..7237f07 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, ¤t->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 105b91d..e6e8a9a 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 b4de9a0..60378dd 100644
--- a/fs/ext2/file.c
+++ b/fs/ext2/file.c
@@ -79,7 +79,7 @@ static ssize_t ext2_dax_write_iter(struct kiocb *iocb, struct iov_iter *from)
/*
* 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 a29e8ea..c668f6b 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 fd6ddfe..06b342d 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 4f0d6f4..d86c0afc 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 81b9854..dbda449 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 3a63d75..52de290 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 403c903..00db81e 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 64f5f9a..4c91fb2 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 202b2c0..80a13c8 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.
*/
