The patch titled
Subject: mm/filemap: use filemap_read_page in filemap_fault
has been added to the -mm tree. Its filename is
mm-filemap-use-filemap_read_page-in-filemap_fault.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/mm-filemap-use-filemap_read_page-in-filemap_fault.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/mm-filemap-use-filemap_read_page-in-filemap_fault.patch
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------------------------------------------------------
From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx>
Subject: mm/filemap: use filemap_read_page in filemap_fault
After splitting generic_file_buffered_read() into smaller parts, it turns
out we can reuse one of the parts in filemap_fault(). This fixes an
oversight -- waiting for the I/O to complete is now interruptible by a
fatal signal. And it saves us a few bytes of text in an unlikely path.
$ ./scripts/bloat-o-meter before.o after.o
add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-207 (-207)
Function old new delta
filemap_fault 2187 1980 -207
Total: Before=37491, After=37284, chg -0.55%
Link: https://lkml.kernel.org/r/20210226140011.2883498-1-willy@xxxxxxxxxxxxx
Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Reviewed-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Kent Overstreet <kent.overstreet@xxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/filemap.c | 10 +---------
1 file changed, 1 insertion(+), 9 deletions(-)
--- a/mm/filemap.c~mm-filemap-use-filemap_read_page-in-filemap_fault
+++ a/mm/filemap.c
@@ -2912,7 +2912,6 @@ vm_fault_t filemap_fault(struct vm_fault
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;
pgoff_t offset = vmf->pgoff;
pgoff_t max_off;
@@ -2999,14 +2998,8 @@ page_not_uptodate:
* because there really aren't any performance issues here
* and we need to check for errors.
*/
- ClearPageError(page);
fpin = maybe_unlock_mmap_for_io(vmf, fpin);
- error = mapping->a_ops->readpage(file, page);
- if (!error) {
- wait_on_page_locked(page);
- if (!PageUptodate(page))
- error = -EIO;
- }
+ error = filemap_read_page(file, mapping, page);
if (fpin)
goto out_retry;
put_page(page);
@@ -3014,7 +3007,6 @@ page_not_uptodate:
if (!error || error == AOP_TRUNCATED_PAGE)
goto retry_find;
- shrink_readahead_size_eio(ra);
return VM_FAULT_SIGBUS;
out_retry:
_
Patches currently in -mm which might be from willy@xxxxxxxxxxxxx are
mm-filemap-use-filemap_read_page-in-filemap_fault.patch
