From: Josef Bacik <josef@toxicpanda.com>
To: kernel-team@fb.com, linux-kernel@vger.kernel.org,
hannes@cmpxchg.org, tj@kernel.org, linux-fsdevel@vger.kernel.org,
akpm@linux-foundation.org, riel@redhat.com, linux-mm@kvack.org,
linux-btrfs@vger.kernel.org
Subject: [PATCH 5/9] mm: drop the mmap_sem in all read fault cases
Date: Wed, 26 Sep 2018 17:08:52 -0400 [thread overview]
Message-ID: <20180926210856.7895-6-josef@toxicpanda.com> (raw)
In-Reply-To: <20180926210856.7895-1-josef@toxicpanda.com>
Johannes' patches didn't quite cover all of the IO cases that we need to
drop the mmap_sem for, this patch covers the rest of them.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
mm/filemap.c | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/mm/filemap.c b/mm/filemap.c
index 1ed35cd99b2c..65395ee132a0 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -2523,6 +2523,7 @@ vm_fault_t filemap_fault(struct vm_fault *vmf)
int error;
struct mm_struct *mm = vmf->vma->vm_mm;
struct file *file = vmf->vma->vm_file;
+ struct file *fpin = NULL;
struct address_space *mapping = file->f_mapping;
struct file_ra_state *ra = &file->f_ra;
struct inode *inode = mapping->host;
@@ -2610,11 +2611,15 @@ vm_fault_t filemap_fault(struct vm_fault *vmf)
return ret | VM_FAULT_LOCKED;
no_cached_page:
+ fpin = maybe_unlock_mmap_for_io(vmf->vma, vmf->flags);
+
/*
* We're only likely to ever get here if MADV_RANDOM is in
* effect.
*/
error = page_cache_read(file, offset, vmf->gfp_mask);
+ if (fpin)
+ goto out_retry;
/*
* The page we want has now been added to the page cache.
@@ -2634,6 +2639,8 @@ vm_fault_t filemap_fault(struct vm_fault *vmf)
return VM_FAULT_SIGBUS;
page_not_uptodate:
+ fpin = maybe_unlock_mmap_for_io(vmf->vma, vmf->flags);
+
/*
* Umm, take care of errors if the page isn't up-to-date.
* Try to re-read it _once_. We do this synchronously,
@@ -2647,6 +2654,8 @@ vm_fault_t filemap_fault(struct vm_fault *vmf)
if (!PageUptodate(page))
error = -EIO;
}
+ if (fpin)
+ goto out_retry;
put_page(page);
if (!error || error == AOP_TRUNCATED_PAGE)
@@ -2665,6 +2674,8 @@ vm_fault_t filemap_fault(struct vm_fault *vmf)
}
out_retry:
+ if (fpin)
+ fput(fpin);
if (page)
put_page(page);
return ret | VM_FAULT_RETRY;
--
2.14.3
next prev parent reply other threads:[~2018-09-26 21:08 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-26 21:08 [RFC][PATCH 0/9][V2] drop the mmap_sem when doing IO in the fault path Josef Bacik
2018-09-26 21:08 ` [PATCH 1/9] mm: infrastructure for page fault page caching Josef Bacik
2018-09-27 16:24 ` Matthew Wilcox
2018-09-26 21:08 ` [PATCH 2/9] mm: drop mmap_sem for page cache read IO submission Josef Bacik
2018-09-26 21:08 ` [PATCH 3/9] mm: clean up swapcache lookup and creation function names Josef Bacik
2018-09-26 21:08 ` [PATCH 4/9] mm: drop mmap_sem for swap read IO submission Josef Bacik
2018-09-26 21:08 ` Josef Bacik [this message]
2018-09-26 21:08 ` [PATCH 6/9] mm: use the cached page for filemap_fault Josef Bacik
2018-09-26 21:08 ` [PATCH 7/9] mm: add a flag to indicate we used a cached page Josef Bacik
2018-09-26 21:08 ` [PATCH 8/9] mm: allow ->page_mkwrite to do retries Josef Bacik
2018-09-26 21:08 ` [PATCH 9/9] btrfs: drop mmap_sem in mkwrite for btrfs Josef Bacik
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