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@xxxxxxxxx> --- fs/dax.c | 35 +++++++++++++++++++++++++++++++++++ fs/ext2/inode.c | 8 +++++--- fs/ext2/xip.c | 14 -------------- fs/ext2/xip.h | 3 --- include/linux/fs.h | 6 ++++++ 5 files changed, 46 insertions(+), 20 deletions(-) diff --git a/fs/dax.c b/fs/dax.c index 108c68e..02e226f 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -20,8 +20,43 @@ #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; + 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; + 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; diff --git a/fs/ext2/inode.c b/fs/ext2/inode.c index 3ccd5fd..52978b8 100644 --- a/fs/ext2/inode.c +++ b/fs/ext2/inode.c @@ -733,10 +733,12 @@ static int ext2_get_blocks(struct inode *inode, if (IS_DAX(inode)) { /* - * we need to clear the block + * block must be initialised before we put it in the tree + * so that it's not found by another thread before it's + * initialised */ - err = ext2_clear_xip_target (inode, - le32_to_cpu(chain[depth-1].key)); + err = dax_clear_blocks(inode, le32_to_cpu(chain[depth-1].key), + 1 << inode->i_blkbits); if (err) { mutex_unlock(&ei->truncate_mutex); goto cleanup; diff --git a/fs/ext2/xip.c b/fs/ext2/xip.c index bbc5fec..8cfca3a 100644 --- a/fs/ext2/xip.c +++ b/fs/ext2/xip.c @@ -42,20 +42,6 @@ __ext2_get_block(struct inode *inode, pgoff_t pgoff, int create, return rc; } -int -ext2_clear_xip_target(struct inode *inode, sector_t block) -{ - void *kaddr; - unsigned long pfn; - long size; - - size = __inode_direct_access(inode, block, &kaddr, &pfn, PAGE_SIZE); - if (size < 0) - return size; - clear_page(kaddr); - return 0; -} - void ext2_xip_verify_sb(struct super_block *sb) { struct ext2_sb_info *sbi = EXT2_SB(sb); diff --git a/fs/ext2/xip.h b/fs/ext2/xip.h index 29be737..b2592f2 100644 --- a/fs/ext2/xip.h +++ b/fs/ext2/xip.h @@ -7,8 +7,6 @@ #ifdef CONFIG_EXT2_FS_XIP extern void ext2_xip_verify_sb (struct super_block *); -extern int ext2_clear_xip_target (struct inode *, sector_t); - static inline int ext2_use_xip (struct super_block *sb) { struct ext2_sb_info *sbi = EXT2_SB(sb); @@ -19,6 +17,5 @@ int ext2_get_xip_mem(struct address_space *, pgoff_t, int, #else #define ext2_xip_verify_sb(sb) do { } while (0) #define ext2_use_xip(sb) 0 -#define ext2_clear_xip_target(inode, chain) 0 #define ext2_get_xip_mem NULL #endif diff --git a/include/linux/fs.h b/include/linux/fs.h index 45839e8..c04d371 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2490,11 +2490,17 @@ extern int generic_file_open(struct inode * inode, struct file * filp); extern int nonseekable_open(struct inode * inode, struct file * filp); #ifdef CONFIG_FS_XIP +int dax_clear_blocks(struct inode *, sector_t block, long size); extern int xip_file_mmap(struct file * file, struct vm_area_struct * vma); extern int xip_truncate_page(struct address_space *mapping, loff_t from); ssize_t dax_do_io(int rw, struct kiocb *, struct inode *, struct iov_iter *, loff_t, get_block_t, dio_iodone_t, int flags); #else +static inline int dax_clear_blocks(struct inode *i, sector_t blk, long sz) +{ + return 0; +} + static inline int xip_truncate_page(struct address_space *mapping, loff_t from) { return 0; -- 2.1.0 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx"> email@xxxxxxxxx </a>