diff options
| author | Dan Williams <dan.j.williams@intel.com> | 2016-01-28 20:25:31 -0800 |
|---|---|---|
| committer | Dan Williams <dan.j.williams@intel.com> | 2016-01-30 13:35:32 -0800 |
| commit | d1a5f2b4d8a125943dcb6b032fc7eaefc2c78296 (patch) | |
| tree | afdd4251d10cbcf34b00bd4f33adb27996881cc6 /block/partition-generic.c | |
| parent | 9f4736fe7ca804aa79b5916221bb13dfc6221a0f (diff) | |
| download | lwn-d1a5f2b4d8a125943dcb6b032fc7eaefc2c78296.tar.gz lwn-d1a5f2b4d8a125943dcb6b032fc7eaefc2c78296.zip | |
block: use DAX for partition table reads
Avoid populating pagecache when the block device is in DAX mode.
Otherwise these page cache entries collide with the fsync/msync
implementation and break data durability guarantees.
Cc: Jan Kara <jack@suse.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Reported-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Tested-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'block/partition-generic.c')
| -rw-r--r-- | block/partition-generic.c | 18 |
1 files changed, 15 insertions, 3 deletions
diff --git a/block/partition-generic.c b/block/partition-generic.c index 746935a5973c..fefd01b496a0 100644 --- a/block/partition-generic.c +++ b/block/partition-generic.c @@ -16,6 +16,7 @@ #include <linux/kmod.h> #include <linux/ctype.h> #include <linux/genhd.h> +#include <linux/dax.h> #include <linux/blktrace_api.h> #include "partitions/check.h" @@ -550,13 +551,24 @@ int invalidate_partitions(struct gendisk *disk, struct block_device *bdev) return 0; } -unsigned char *read_dev_sector(struct block_device *bdev, sector_t n, Sector *p) +static struct page *read_pagecache_sector(struct block_device *bdev, sector_t n) { struct address_space *mapping = bdev->bd_inode->i_mapping; + + return read_mapping_page(mapping, (pgoff_t)(n >> (PAGE_CACHE_SHIFT-9)), + NULL); +} + +unsigned char *read_dev_sector(struct block_device *bdev, sector_t n, Sector *p) +{ struct page *page; - page = read_mapping_page(mapping, (pgoff_t)(n >> (PAGE_CACHE_SHIFT-9)), - NULL); + /* don't populate page cache for dax capable devices */ + if (IS_DAX(bdev->bd_inode)) + page = read_dax_sector(bdev, n); + else + page = read_pagecache_sector(bdev, n); + if (!IS_ERR(page)) { if (PageError(page)) goto fail; |