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authorMatthew Wilcox <matthew.r.wilcox@intel.com>2015-02-16 15:58:59 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2015-02-16 17:56:03 -0800
commit289c6aedac981533331428bc933fff21ae332c9e (patch)
tree1be218c77a0ea9f0a29c130abe1cd23fe5af7ca9 /fs/dax.c
parentd475c6346a38aef3058eba96867bfa726a3cc940 (diff)
dax,ext2: replace ext2_clear_xip_target with dax_clear_blocks
This is practically generic code; other filesystems will want to call it from other places, but there's nothing ext2-specific about it. Make it a little more generic by allowing it to take a count of the number of bytes to zero rather than fixing it to a single page. Thanks to Dave Hansen for suggesting that I need to call cond_resched() if zeroing more than one page. Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com> Cc: Andreas Dilger <andreas.dilger@intel.com> Cc: Boaz Harrosh <boaz@plexistor.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Dave Chinner <david@fromorbit.com> Cc: Jan Kara <jack@suse.cz> Cc: Jens Axboe <axboe@kernel.dk> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/dax.c')
-rw-r--r--fs/dax.c37
1 files changed, 37 insertions, 0 deletions
diff --git a/fs/dax.c b/fs/dax.c
index 1a2bdbfa3ea9..69c3126a05b4 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -20,8 +20,45 @@
#include <linux/fs.h>
#include <linux/genhd.h>
#include <linux/mutex.h>
+#include <linux/sched.h>
#include <linux/uio.h>
+int dax_clear_blocks(struct inode *inode, sector_t block, long size)
+{
+ struct block_device *bdev = inode->i_sb->s_bdev;
+ sector_t sector = block << (inode->i_blkbits - 9);
+
+ might_sleep();
+ do {
+ void *addr;
+ unsigned long pfn;
+ long count;
+
+ count = bdev_direct_access(bdev, sector, &addr, &pfn, size);
+ if (count < 0)
+ return count;
+ BUG_ON(size < count);
+ while (count > 0) {
+ unsigned pgsz = PAGE_SIZE - offset_in_page(addr);
+ if (pgsz > count)
+ pgsz = count;
+ if (pgsz < PAGE_SIZE)
+ memset(addr, 0, pgsz);
+ else
+ clear_page(addr);
+ addr += pgsz;
+ size -= pgsz;
+ count -= pgsz;
+ BUG_ON(pgsz & 511);
+ sector += pgsz / 512;
+ cond_resched();
+ }
+ } while (size);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(dax_clear_blocks);
+
static long dax_get_addr(struct buffer_head *bh, void **addr, unsigned blkbits)
{
unsigned long pfn;