diff options
| -rw-r--r-- | fs/dax.c | 44 | ||||
| -rw-r--r-- | fs/ext2/inode.c | 2 | ||||
| -rw-r--r-- | include/linux/fs.h | 10 | ||||
| -rw-r--r-- | mm/filemap_xip.c | 40 |
4 files changed, 46 insertions, 50 deletions
@@ -462,3 +462,47 @@ int dax_fault(struct vm_area_struct *vma, struct vm_fault *vmf, return result; } EXPORT_SYMBOL_GPL(dax_fault); + +/** + * dax_truncate_page - handle a partial page being truncated in a DAX file + * @inode: The file being truncated + * @from: The file offset that is being truncated to + * @get_block: The filesystem method used to translate file offsets to blocks + * + * Similar to block_truncate_page(), this function can be called by a + * filesystem when it is truncating an DAX file to handle the partial page. + * + * We work in terms of PAGE_CACHE_SIZE here for commonality with + * block_truncate_page(), but we could go down to PAGE_SIZE if the filesystem + * took care of disposing of the unnecessary blocks. Even if the filesystem + * block size is smaller than PAGE_SIZE, we have to zero the rest of the page + * since the file might be mmaped. + */ +int dax_truncate_page(struct inode *inode, loff_t from, get_block_t get_block) +{ + struct buffer_head bh; + pgoff_t index = from >> PAGE_CACHE_SHIFT; + unsigned offset = from & (PAGE_CACHE_SIZE-1); + unsigned length = PAGE_CACHE_ALIGN(from) - from; + int err; + + /* Block boundary? Nothing to do */ + if (!length) + return 0; + + memset(&bh, 0, sizeof(bh)); + bh.b_size = PAGE_CACHE_SIZE; + err = get_block(inode, index, &bh, 0); + if (err < 0) + return err; + if (buffer_written(&bh)) { + void *addr; + err = dax_get_addr(&bh, &addr, inode->i_blkbits); + if (err < 0) + return err; + memset(addr + offset, 0, length); + } + + return 0; +} +EXPORT_SYMBOL_GPL(dax_truncate_page); diff --git a/fs/ext2/inode.c b/fs/ext2/inode.c index 52978b853226..5ac0a3461b3c 100644 --- a/fs/ext2/inode.c +++ b/fs/ext2/inode.c @@ -1210,7 +1210,7 @@ static int ext2_setsize(struct inode *inode, loff_t newsize) inode_dio_wait(inode); if (IS_DAX(inode)) - error = xip_truncate_page(inode->i_mapping, newsize); + error = dax_truncate_page(inode, newsize, ext2_get_block); else if (test_opt(inode->i_sb, NOBH)) error = nobh_truncate_page(inode->i_mapping, newsize, ext2_get_block); diff --git a/include/linux/fs.h b/include/linux/fs.h index 6bad6d4c579b..2c8f9055af38 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2591,18 +2591,10 @@ extern int nonseekable_open(struct inode * inode, struct file * filp); ssize_t dax_do_io(int rw, struct kiocb *, struct inode *, struct iov_iter *, loff_t, get_block_t, dio_iodone_t, int flags); int dax_clear_blocks(struct inode *, sector_t block, long size); +int dax_truncate_page(struct inode *, loff_t from, get_block_t); int dax_fault(struct vm_area_struct *, struct vm_fault *, get_block_t); #define dax_mkwrite(vma, vmf, gb) dax_fault(vma, vmf, gb) -#ifdef CONFIG_FS_XIP -extern int xip_truncate_page(struct address_space *mapping, loff_t from); -#else -static inline int xip_truncate_page(struct address_space *mapping, loff_t from) -{ - return 0; -} -#endif - #ifdef CONFIG_BLOCK typedef void (dio_submit_t)(int rw, struct bio *bio, struct inode *inode, loff_t file_offset); diff --git a/mm/filemap_xip.c b/mm/filemap_xip.c index 59fb387b2238..8e3f99b61959 100644 --- a/mm/filemap_xip.c +++ b/mm/filemap_xip.c @@ -22,43 +22,3 @@ #include <asm/tlbflush.h> #include <asm/io.h> -/* - * truncate a page used for execute in place - * functionality is analog to block_truncate_page but does use get_xip_mem - * to get the page instead of page cache - */ -int -xip_truncate_page(struct address_space *mapping, loff_t from) -{ - pgoff_t index = from >> PAGE_CACHE_SHIFT; - unsigned offset = from & (PAGE_CACHE_SIZE-1); - unsigned blocksize; - unsigned length; - void *xip_mem; - unsigned long xip_pfn; - int err; - - BUG_ON(!mapping->a_ops->get_xip_mem); - - blocksize = 1 << mapping->host->i_blkbits; - length = offset & (blocksize - 1); - - /* Block boundary? Nothing to do */ - if (!length) - return 0; - - length = blocksize - length; - - err = mapping->a_ops->get_xip_mem(mapping, index, 0, - &xip_mem, &xip_pfn); - if (unlikely(err)) { - if (err == -ENODATA) - /* Hole? No need to truncate */ - return 0; - else - return err; - } - memset(xip_mem + offset, 0, length); - return 0; -} -EXPORT_SYMBOL_GPL(xip_truncate_page); |