mm: Fix comments mentioning i_mutex (9608703e) · Commits · EulixOS / Software / Kernel

mm/filemap.c

+5 −5

Original line number	Diff line number	Diff line
		@@ -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

mm/madvise.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -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.

mm/memory-failure.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -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:

mm/rmap.c

+3 −3

Original line number	Diff line number	Diff line
		@@ -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
		*

mm/shmem.c

+10 −10

Original line number	Diff line number	Diff line
		@@ -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;