It takes a get_block parameter just like nobh_truncate_page() and block_truncate_page() Signed-off-by: Matthew Wilcox <matthew.r.wilcox@xxxxxxxxx> --- fs/dax.c | 44 ++++++++++++++++++++++++++++++++++++++++++++ fs/ext2/inode.c | 2 +- include/linux/fs.h | 4 ++-- mm/filemap_xip.c | 40 ---------------------------------------- 4 files changed, 47 insertions(+), 43 deletions(-) diff --git a/fs/dax.c b/fs/dax.c index 4ab4890..b9bc5e2 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -449,3 +449,47 @@ int dax_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf, return dax_fault(vma, vmf, get_block); } EXPORT_SYMBOL_GPL(dax_mkwrite); + +/** + * 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 52978b8..5ac0a34 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 d4259e1..29fafaf 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2465,7 +2465,7 @@ 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_truncate_page(struct address_space *mapping, loff_t from); +int dax_truncate_page(struct inode *, loff_t from, get_block_t); 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_fault(struct vm_area_struct *, struct vm_fault *, get_block_t); @@ -2476,7 +2476,7 @@ 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) +static inline int dax_truncate_page(struct inode *i, loff_t frm, get_block_t gb) { return 0; } diff --git a/mm/filemap_xip.c b/mm/filemap_xip.c index 9dd45f3..6316578 100644 --- a/mm/filemap_xip.c +++ b/mm/filemap_xip.c @@ -21,43 +21,3 @@ #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); -- 2.0.0 -- 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>