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Date: Sun, 31 Jan 2016 23:19:53 +1100
From: Matthew Wilcox <matthew.r.wilcox@...el.com>
To: Andrew Morton <akpm@...ux-foundation.org>
Cc: Matthew Wilcox <matthew.r.wilcox@...el.com>, linux-mm@...ck.org,
linux-nvdimm@...ts.01.org, linux-fsdevel@...r.kernel.org,
linux-kernel@...r.kernel.org, willy@...ux.intel.com
Subject: [PATCH 4/6] dax: Use PAGE_CACHE_SIZE where appropriate
We were a little sloppy about using PAGE_SIZE instead of PAGE_CACHE_SIZE.
The important thing to remember is that the VM is gicing us a pgoff_t
and asking us to populate that. If PAGE_CACHE_SIZE were larger than
PAGE_SIZE, then we would not successfully fill in the PTEs for faults
that occurred in the upper portions of PAGE_CACHE_SIZE.
Of course, we actually only fill in one PTE, so this still doesn't solve
the problem. I have my doubts we will ever increase PAGE_CACHE_SIZE
now that we have map_pages.
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@...el.com>
---
fs/dax.c | 28 ++++++++++++++--------------
1 file changed, 14 insertions(+), 14 deletions(-)
diff --git a/fs/dax.c b/fs/dax.c
index d0e1334..f0c204d 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -558,14 +558,14 @@ static int dax_pte_fault(struct vm_area_struct *vma, struct vm_fault *vmf,
int error;
int major = 0;
- size = (i_size_read(inode) + PAGE_SIZE - 1) >> PAGE_SHIFT;
+ size = (i_size_read(inode) + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
if (vmf->pgoff >= size)
return VM_FAULT_SIGBUS;
memset(&bh, 0, sizeof(bh));
- block = (sector_t)vmf->pgoff << (PAGE_SHIFT - blkbits);
+ block = (sector_t)vmf->pgoff << (PAGE_CACHE_SHIFT - blkbits);
bh.b_bdev = inode->i_sb->s_bdev;
- bh.b_size = PAGE_SIZE;
+ bh.b_size = PAGE_CACHE_SIZE;
repeat:
page = find_get_page(mapping, vmf->pgoff);
@@ -582,7 +582,7 @@ static int dax_pte_fault(struct vm_area_struct *vma, struct vm_fault *vmf,
}
error = get_block(inode, block, &bh, 0);
- if (!error && (bh.b_size < PAGE_SIZE))
+ if (!error && (bh.b_size < PAGE_CACHE_SIZE))
error = -EIO; /* fs corruption? */
if (error)
goto unlock_page;
@@ -593,7 +593,7 @@ static int dax_pte_fault(struct vm_area_struct *vma, struct vm_fault *vmf,
count_vm_event(PGMAJFAULT);
mem_cgroup_count_vm_event(vma->vm_mm, PGMAJFAULT);
major = VM_FAULT_MAJOR;
- if (!error && (bh.b_size < PAGE_SIZE))
+ if (!error && (bh.b_size < PAGE_CACHE_SIZE))
error = -EIO;
if (error)
goto unlock_page;
@@ -630,7 +630,7 @@ static int dax_pte_fault(struct vm_area_struct *vma, struct vm_fault *vmf,
page = find_lock_page(mapping, vmf->pgoff);
if (page) {
- unmap_mapping_range(mapping, vmf->pgoff << PAGE_SHIFT,
+ unmap_mapping_range(mapping, vmf->pgoff << PAGE_CACHE_SHIFT,
PAGE_CACHE_SIZE, 0);
delete_from_page_cache(page);
unlock_page(page);
@@ -677,7 +677,7 @@ static int dax_pte_fault(struct vm_area_struct *vma, struct vm_fault *vmf,
* The 'colour' (ie low bits) within a PMD of a page offset. This comes up
* more often than one might expect in the below function.
*/
-#define PG_PMD_COLOUR ((PMD_SIZE >> PAGE_SHIFT) - 1)
+#define PG_PMD_COLOUR ((PMD_SIZE >> PAGE_CACHE_SHIFT) - 1)
static void __dax_dbg(struct buffer_head *bh, unsigned long address,
const char *reason, const char *fn)
@@ -734,7 +734,7 @@ static int dax_pmd_fault(struct vm_area_struct *vma, struct vm_fault *vmf,
return VM_FAULT_FALLBACK;
}
- size = (i_size_read(inode) + PAGE_SIZE - 1) >> PAGE_SHIFT;
+ size = (i_size_read(inode) + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
if (vmf->pgoff >= size)
return VM_FAULT_SIGBUS;
/* If the PMD would cover blocks out of the file */
@@ -746,7 +746,7 @@ static int dax_pmd_fault(struct vm_area_struct *vma, struct vm_fault *vmf,
memset(&bh, 0, sizeof(bh));
bh.b_bdev = inode->i_sb->s_bdev;
- block = (sector_t)vmf->pgoff << (PAGE_SHIFT - blkbits);
+ block = (sector_t)vmf->pgoff << (PAGE_CACHE_SHIFT - blkbits);
bh.b_size = PMD_SIZE;
@@ -776,7 +776,7 @@ static int dax_pmd_fault(struct vm_area_struct *vma, struct vm_fault *vmf,
* zero pages covering this hole
*/
if (alloc) {
- loff_t lstart = vmf->pgoff << PAGE_SHIFT;
+ loff_t lstart = vmf->pgoff << PAGE_CACHE_SHIFT;
loff_t lend = lstart + PMD_SIZE - 1; /* inclusive */
truncate_pagecache_range(inode, lstart, lend);
@@ -904,7 +904,7 @@ static int dax_pmd_fault(struct vm_area_struct *vma, struct vm_fault *vmf,
* The 'colour' (ie low bits) within a PUD of a page offset. This comes up
* more often than one might expect in the below function.
*/
-#define PG_PUD_COLOUR ((PUD_SIZE >> PAGE_SHIFT) - 1)
+#define PG_PUD_COLOUR ((PUD_SIZE >> PAGE_CACHE_SHIFT) - 1)
#define dax_pud_dbg(bh, address, reason) __dax_dbg(bh, address, reason, "dax_pud")
@@ -945,7 +945,7 @@ static int dax_pud_fault(struct vm_area_struct *vma, struct vm_fault *vmf,
return VM_FAULT_FALLBACK;
}
- size = (i_size_read(inode) + PAGE_SIZE - 1) >> PAGE_SHIFT;
+ size = (i_size_read(inode) + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
if (vmf->pgoff >= size)
return VM_FAULT_SIGBUS;
/* If the PUD would cover blocks out of the file */
@@ -957,7 +957,7 @@ static int dax_pud_fault(struct vm_area_struct *vma, struct vm_fault *vmf,
memset(&bh, 0, sizeof(bh));
bh.b_bdev = inode->i_sb->s_bdev;
- block = (sector_t)vmf->pgoff << (PAGE_SHIFT - blkbits);
+ block = (sector_t)vmf->pgoff << (PAGE_CACHE_SHIFT - blkbits);
bh.b_size = PUD_SIZE;
@@ -987,7 +987,7 @@ static int dax_pud_fault(struct vm_area_struct *vma, struct vm_fault *vmf,
* zero pages covering this hole
*/
if (alloc) {
- loff_t lstart = vmf->pgoff << PAGE_SHIFT;
+ loff_t lstart = vmf->pgoff << PAGE_CACHE_SHIFT;
loff_t lend = lstart + PUD_SIZE - 1; /* inclusive */
truncate_pagecache_range(inode, lstart, lend);
--
2.7.0.rc3
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