[PATCH 01/14] mm: Fix comments mentioning i_mutex

Jan Kara
2021-07-12T16:56:21Z

inode->i_mutex has been replaced with inode->i_rwsem long ago. Fix
comments still mentioning i_mutex.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Acked-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Jan Kara <jack@suse.cz>
---
mm/filemap.c | 10 +++++-----
mm/madvise.c | 2 +-
mm/memory-failure.c | 2 +-
mm/rmap.c | 6 +++---
mm/shmem.c | 20 ++++++++++----------
mm/truncate.c | 8 ++++----
6 files changed, 24 insertions(+), 24 deletions(-)

diff --git a/mm/filemap.c b/mm/filemap.c
index d1458ecf2f51..acf20eca2fa4 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -76,7 +76,7 @@
* ->swap_lock (exclusive_swap_page, others)
* ->i_pages lock
*
- * ->i_mutex
+ * ->i_rwsem
* ->i_mmap_rwsem (truncate->unmap_mapping_range)
*
* ->mmap_lock
@@ -87,7 +87,7 @@
* ->mmap_lock
* ->lock_page (access_process_vm)
*
- * ->i_mutex (generic_perform_write)
+ * ->i_rwsem (generic_perform_write)
* ->mmap_lock (fault_in_pages_readable->do_page_fault)
*
* bdi->wb.list_lock
@@ -3704,12 +3704,12 @@ EXPORT_SYMBOL(generic_perform_write);
* modification times and calls proper subroutines depending on whether we
* do direct IO or a standard buffered write.
*
- * It expects i_mutex to be grabbed unless we work on a block device or similar
+ * It expects i_rwsem to be grabbed unless we work on a block device or similar
* object which does not need locking at all.
*
* This function does *not* take care of syncing data in case of O_SYNC write.
* A caller has to handle it. This is mainly due to the fact that we want to
- * avoid syncing under i_mutex.
+ * avoid syncing under i_rwsem.
*
* Return:
* * number of bytes written, even for truncated writes
@@ -3797,7 +3797,7 @@ EXPORT_SYMBOL(__generic_file_write_iter);
*
* This is a wrapper around __generic_file_write_iter() to be used by most
* filesystems. It takes care of syncing the file in case of O_SYNC file
- * and acquires i_mutex as needed.
+ * and acquires i_rwsem as needed.
* Return:
* * negative error code if no data has been written at all of
* vfs_fsync_range() failed for a synchronous write
diff --git a/mm/madvise.c b/mm/madvise.c
index 6d3d348b17f4..012129fbfaf8 100644
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -910,7 +910,7 @@ static long madvise_remove(struct vm_area_struct *vma,
+ ((loff_t)vma->vm_pgoff << PAGE_SHIFT);

/*
- * Filesystem's fallocate may need to take i_mutex. We need to
+ * Filesystem's fallocate may need to take i_rwsem. We need to
* explicitly grab a reference because the vma (and hence the
* vma's reference to the file) can go away as soon as we drop
* mmap_lock.
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index eefd823deb67..0edce65731f7 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -866,7 +866,7 @@ static int me_pagecache_clean(struct page *p, unsigned long pfn)
/*
* Truncation is a bit tricky. Enable it per file system for now.
*
- * Open: to take i_mutex or not for this? Right now we don't.
+ * Open: to take i_rwsem or not for this? Right now we don't.
*/
ret = truncate_error_page(p, pfn, mapping);
out:
diff --git a/mm/rmap.c b/mm/rmap.c
index 795f9d5f8386..a8b01929ab2e 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -20,9 +20,9 @@
/*
* Lock ordering in mm:
*
- * inode->i_mutex (while writing or truncating, not reading or faulting)
+ * inode->i_rwsem (while writing or truncating, not reading or faulting)
* mm->mmap_lock
- * page->flags PG_locked (lock_page) * (see huegtlbfs below)
+ * page->flags PG_locked (lock_page) * (see hugetlbfs below)
* hugetlbfs_i_mmap_rwsem_key (in huge_pmd_share)
* mapping->i_mmap_rwsem
* hugetlb_fault_mutex (hugetlbfs specific page fault mutex)
@@ -41,7 +41,7 @@
* in arch-dependent flush_dcache_mmap_lock,
* within bdi.wb->list_lock in __sync_single_inode)
*
- * anon_vma->rwsem,mapping->i_mutex (memory_failure, collect_procs_anon)
+ * anon_vma->rwsem,mapping->i_mmap_rwsem (memory_failure, collect_procs_anon)
* ->tasklist_lock
* pte map lock
*
diff --git a/mm/shmem.c b/mm/shmem.c
index 70d9ce294bb4..9af4b2173fe9 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -96,7 +96,7 @@ static struct vfsmount *shm_mnt;

/*
* shmem_fallocate communicates with shmem_fault or shmem_writepage via
- * inode->i_private (with i_mutex making sure that it has only one user at
+ * inode->i_private (with i_rwsem making sure that it has only one user at
* a time): we would prefer not to enlarge the shmem inode just for that.
*/
struct shmem_falloc {
@@ -774,7 +774,7 @@ static int shmem_free_swap(struct address_space *mapping,
* Determine (in bytes) how many of the shmem object's pages mapped by the
* given offsets are swapped out.
*
- * This is safe to call without i_mutex or the i_pages lock thanks to RCU,
+ * This is safe to call without i_rwsem or the i_pages lock thanks to RCU,
* as long as the inode doesn't go away and racy results are not a problem.
*/
unsigned long shmem_partial_swap_usage(struct address_space *mapping,
@@ -806,7 +806,7 @@ unsigned long shmem_partial_swap_usage(struct address_space *mapping,
* Determine (in bytes) how many of the shmem object's pages mapped by the
* given vma is swapped out.
*
- * This is safe to call without i_mutex or the i_pages lock thanks to RCU,
+ * This is safe to call without i_rwsem or the i_pages lock thanks to RCU,
* as long as the inode doesn't go away and racy results are not a problem.
*/
unsigned long shmem_swap_usage(struct vm_area_struct *vma)
@@ -1069,7 +1069,7 @@ static int shmem_setattr(struct user_namespace *mnt_userns,
loff_t oldsize = inode->i_size;
loff_t newsize = attr->ia_size;

- /* protected by i_mutex */
+ /* protected by i_rwsem */
if ((newsize < oldsize && (info->seals & F_SEAL_SHRINK)) ||
(newsize > oldsize && (info->seals & F_SEAL_GROW)))
return -EPERM;
@@ -2071,7 +2071,7 @@ static vm_fault_t shmem_fault(struct vm_fault *vmf)
/*
* Trinity finds that probing a hole which tmpfs is punching can
* prevent the hole-punch from ever completing: which in turn
- * locks writers out with its hold on i_mutex. So refrain from
+ * locks writers out with its hold on i_rwsem. So refrain from
* faulting pages into the hole while it's being punched. Although
* shmem_undo_range() does remove the additions, it may be unable to
* keep up, as each new page needs its own unmap_mapping_range() call,
@@ -2082,7 +2082,7 @@ static vm_fault_t shmem_fault(struct vm_fault *vmf)
* we just need to make racing faults a rare case.
*
* The implementation below would be much simpler if we just used a
- * standard mutex or completion: but we cannot take i_mutex in fault,
+ * standard mutex or completion: but we cannot take i_rwsem in fault,
* and bloating every shmem inode for this unlikely case would be sad.
*/
if (unlikely(inode->i_private)) {
@@ -2482,7 +2482,7 @@ shmem_write_begin(struct file *file, struct address_space *mapping,
struct shmem_inode_info *info = SHMEM_I(inode);
pgoff_t index = pos >> PAGE_SHIFT;

- /* i_mutex is held by caller */
+ /* i_rwsem is held by caller */
if (unlikely(info->seals & (F_SEAL_GROW |
F_SEAL_WRITE | F_SEAL_FUTURE_WRITE))) {
if (info->seals & (F_SEAL_WRITE | F_SEAL_FUTURE_WRITE))
@@ -2582,7 +2582,7 @@ static ssize_t shmem_file_read_iter(struct kiocb *iocb, struct iov_iter *to)

/*
* We must evaluate after, since reads (unlike writes)
- * are called without i_mutex protection against truncate
+ * are called without i_rwsem protection against truncate
*/
nr = PAGE_SIZE;
i_size = i_size_read(inode);
@@ -2652,7 +2652,7 @@ static loff_t shmem_file_llseek(struct file *file, loff_t offset, int whence)
return -ENXIO;

inode_lock(inode);
- /* We're holding i_mutex so we can access i_size directly */
+ /* We're holding i_rwsem so we can access i_size directly */
offset = mapping_seek_hole_data(mapping, offset, inode->i_size, whence);
if (offset >= 0)
offset = vfs_setpos(file, offset, MAX_LFS_FILESIZE);
@@ -2681,7 +2681,7 @@ static long shmem_fallocate(struct file *file, int mode, loff_t offset,
loff_t unmap_end = round_down(offset + len, PAGE_SIZE) - 1;
DECLARE_WAIT_QUEUE_HEAD_ONSTACK(shmem_falloc_waitq);

- /* protected by i_mutex */
+ /* protected by i_rwsem */
if (info->seals & (F_SEAL_WRITE | F_SEAL_FUTURE_WRITE)) {
error = -EPERM;
goto out;
diff --git a/mm/truncate.c b/mm/truncate.c
index 234ddd879caa..0f9becee9789 100644
--- a/mm/truncate.c
+++ b/mm/truncate.c
@@ -412,7 +412,7 @@ EXPORT_SYMBOL(truncate_inode_pages_range);
* @mapping: mapping to truncate
* @lstart: offset from which to truncate
*
- * Called under (and serialised by) inode->i_mutex.
+ * Called under (and serialised by) inode->i_rwsem.
*
* Note: When this function returns, there can be a page in the process of
* deletion (inside __delete_from_page_cache()) in the specified range. Thus
@@ -429,7 +429,7 @@ EXPORT_SYMBOL(truncate_inode_pages);
* truncate_inode_pages_final - truncate *all* pages before inode dies
* @mapping: mapping to truncate
*
- * Called under (and serialized by) inode->i_mutex.
+ * Called under (and serialized by) inode->i_rwsem.
*
* Filesystems have to use this in the .evict_inode path to inform the
* VM that this is the final truncate and the inode is going away.
@@ -748,7 +748,7 @@ EXPORT_SYMBOL(truncate_pagecache);
* setattr function when ATTR_SIZE is passed in.
*
* Must be called with a lock serializing truncates and writes (generally
- * i_mutex but e.g. xfs uses a different lock) and before all filesystem
+ * i_rwsem but e.g. xfs uses a different lock) and before all filesystem
* specific block truncation has been performed.
*/
void truncate_setsize(struct inode *inode, loff_t newsize)
@@ -777,7 +777,7 @@ EXPORT_SYMBOL(truncate_setsize);
*
* The function must be called after i_size is updated so that page fault
* coming after we unlock the page will already see the new i_size.
- * The function must be called while we still hold i_mutex - this not only
+ * The function must be called while we still hold i_rwsem - this not only
* makes sure i_size is stable but also that userspace cannot observe new
* i_size value before we are prepared to store mmap writes at new inode size.
*/
--
2.26.2