From 68a9f5e7007c1afa2cf6830b690a90d0187c0684 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 21 Jun 2016 09:53:44 +1000 Subject: xfs: implement iomap based buffered write path Convert XFS to use the new iomap based multipage write path. This involves implementing the ->iomap_begin and ->iomap_end methods, and switching the buffered file write, page_mkwrite and xfs_iozero paths to the new iomap helpers. With this change __xfs_get_blocks will never be used for buffered writes, and the code handling them can be removed. Based on earlier code from Dave Chinner. Signed-off-by: Christoph Hellwig Reviewed-by: Bob Peterson Signed-off-by: Dave Chinner --- fs/xfs/xfs_aops.c | 212 ------------------------------------------------------ 1 file changed, 212 deletions(-) (limited to 'fs/xfs/xfs_aops.c') diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c index 4c463b99fe57..2ac9f7e5f504 100644 --- a/fs/xfs/xfs_aops.c +++ b/fs/xfs/xfs_aops.c @@ -1427,216 +1427,6 @@ xfs_vm_direct_IO( xfs_get_blocks_direct, endio, NULL, flags); } -/* - * Punch out the delalloc blocks we have already allocated. - * - * Don't bother with xfs_setattr given that nothing can have made it to disk yet - * as the page is still locked at this point. - */ -STATIC void -xfs_vm_kill_delalloc_range( - struct inode *inode, - loff_t start, - loff_t end) -{ - struct xfs_inode *ip = XFS_I(inode); - xfs_fileoff_t start_fsb; - xfs_fileoff_t end_fsb; - int error; - - start_fsb = XFS_B_TO_FSB(ip->i_mount, start); - end_fsb = XFS_B_TO_FSB(ip->i_mount, end); - if (end_fsb <= start_fsb) - return; - - xfs_ilock(ip, XFS_ILOCK_EXCL); - error = xfs_bmap_punch_delalloc_range(ip, start_fsb, - end_fsb - start_fsb); - if (error) { - /* something screwed, just bail */ - if (!XFS_FORCED_SHUTDOWN(ip->i_mount)) { - xfs_alert(ip->i_mount, - "xfs_vm_write_failed: unable to clean up ino %lld", - ip->i_ino); - } - } - xfs_iunlock(ip, XFS_ILOCK_EXCL); -} - -STATIC void -xfs_vm_write_failed( - struct inode *inode, - struct page *page, - loff_t pos, - unsigned len) -{ - loff_t block_offset; - loff_t block_start; - loff_t block_end; - loff_t from = pos & (PAGE_SIZE - 1); - loff_t to = from + len; - struct buffer_head *bh, *head; - struct xfs_mount *mp = XFS_I(inode)->i_mount; - - /* - * The request pos offset might be 32 or 64 bit, this is all fine - * on 64-bit platform. However, for 64-bit pos request on 32-bit - * platform, the high 32-bit will be masked off if we evaluate the - * block_offset via (pos & PAGE_MASK) because the PAGE_MASK is - * 0xfffff000 as an unsigned long, hence the result is incorrect - * which could cause the following ASSERT failed in most cases. - * In order to avoid this, we can evaluate the block_offset of the - * start of the page by using shifts rather than masks the mismatch - * problem. - */ - block_offset = (pos >> PAGE_SHIFT) << PAGE_SHIFT; - - ASSERT(block_offset + from == pos); - - head = page_buffers(page); - block_start = 0; - for (bh = head; bh != head || !block_start; - bh = bh->b_this_page, block_start = block_end, - block_offset += bh->b_size) { - block_end = block_start + bh->b_size; - - /* skip buffers before the write */ - if (block_end <= from) - continue; - - /* if the buffer is after the write, we're done */ - if (block_start >= to) - break; - - /* - * Process delalloc and unwritten buffers beyond EOF. We can - * encounter unwritten buffers in the event that a file has - * post-EOF unwritten extents and an extending write happens to - * fail (e.g., an unaligned write that also involves a delalloc - * to the same page). - */ - if (!buffer_delay(bh) && !buffer_unwritten(bh)) - continue; - - if (!xfs_mp_fail_writes(mp) && !buffer_new(bh) && - block_offset < i_size_read(inode)) - continue; - - if (buffer_delay(bh)) - xfs_vm_kill_delalloc_range(inode, block_offset, - block_offset + bh->b_size); - - /* - * This buffer does not contain data anymore. make sure anyone - * who finds it knows that for certain. - */ - clear_buffer_delay(bh); - clear_buffer_uptodate(bh); - clear_buffer_mapped(bh); - clear_buffer_new(bh); - clear_buffer_dirty(bh); - clear_buffer_unwritten(bh); - } - -} - -/* - * This used to call block_write_begin(), but it unlocks and releases the page - * on error, and we need that page to be able to punch stale delalloc blocks out - * on failure. hence we copy-n-waste it here and call xfs_vm_write_failed() at - * the appropriate point. - */ -STATIC int -xfs_vm_write_begin( - struct file *file, - struct address_space *mapping, - loff_t pos, - unsigned len, - unsigned flags, - struct page **pagep, - void **fsdata) -{ - pgoff_t index = pos >> PAGE_SHIFT; - struct page *page; - int status; - struct xfs_mount *mp = XFS_I(mapping->host)->i_mount; - - ASSERT(len <= PAGE_SIZE); - - page = grab_cache_page_write_begin(mapping, index, flags); - if (!page) - return -ENOMEM; - - status = __block_write_begin(page, pos, len, xfs_get_blocks); - if (xfs_mp_fail_writes(mp)) - status = -EIO; - if (unlikely(status)) { - struct inode *inode = mapping->host; - size_t isize = i_size_read(inode); - - xfs_vm_write_failed(inode, page, pos, len); - unlock_page(page); - - /* - * If the write is beyond EOF, we only want to kill blocks - * allocated in this write, not blocks that were previously - * written successfully. - */ - if (xfs_mp_fail_writes(mp)) - isize = 0; - if (pos + len > isize) { - ssize_t start = max_t(ssize_t, pos, isize); - - truncate_pagecache_range(inode, start, pos + len); - } - - put_page(page); - page = NULL; - } - - *pagep = page; - return status; -} - -/* - * On failure, we only need to kill delalloc blocks beyond EOF in the range of - * this specific write because they will never be written. Previous writes - * beyond EOF where block allocation succeeded do not need to be trashed, so - * only new blocks from this write should be trashed. For blocks within - * EOF, generic_write_end() zeros them so they are safe to leave alone and be - * written with all the other valid data. - */ -STATIC int -xfs_vm_write_end( - struct file *file, - struct address_space *mapping, - loff_t pos, - unsigned len, - unsigned copied, - struct page *page, - void *fsdata) -{ - int ret; - - ASSERT(len <= PAGE_SIZE); - - ret = generic_write_end(file, mapping, pos, len, copied, page, fsdata); - if (unlikely(ret < len)) { - struct inode *inode = mapping->host; - size_t isize = i_size_read(inode); - loff_t to = pos + len; - - if (to > isize) { - /* only kill blocks in this write beyond EOF */ - if (pos > isize) - isize = pos; - xfs_vm_kill_delalloc_range(inode, isize, to); - truncate_pagecache_range(inode, isize, to); - } - } - return ret; -} - STATIC sector_t xfs_vm_bmap( struct address_space *mapping, @@ -1747,8 +1537,6 @@ const struct address_space_operations xfs_address_space_operations = { .set_page_dirty = xfs_vm_set_page_dirty, .releasepage = xfs_vm_releasepage, .invalidatepage = xfs_vm_invalidatepage, - .write_begin = xfs_vm_write_begin, - .write_end = xfs_vm_write_end, .bmap = xfs_vm_bmap, .direct_IO = xfs_vm_direct_IO, .migratepage = buffer_migrate_page, -- cgit v1.2.3-55-g7522