diff options
| -rw-r--r-- | fs/ext4/inode.c | 107 |
1 files changed, 66 insertions, 41 deletions
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 787497d536b6..19fa2e076275 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -1890,6 +1890,26 @@ static int ext4_writepage(struct page *page, return ret; } +static int mpage_submit_page(struct mpage_da_data *mpd, struct page *page) +{ + int len; + loff_t size = i_size_read(mpd->inode); + int err; + + BUG_ON(page->index != mpd->first_page); + if (page->index == size >> PAGE_CACHE_SHIFT) + len = size & ~PAGE_CACHE_MASK; + else + len = PAGE_CACHE_SIZE; + clear_page_dirty_for_io(page); + err = ext4_bio_write_page(&mpd->io_submit, page, len, mpd->wbc); + if (!err) + mpd->wbc->nr_to_write--; + mpd->first_page++; + + return err; +} + #define BH_FLAGS ((1 << BH_Unwritten) | (1 << BH_Delay)) /* @@ -1948,12 +1968,29 @@ static bool mpage_add_bh_to_extent(struct mpage_da_data *mpd, ext4_lblk_t lblk, return false; } -static bool add_page_bufs_to_extent(struct mpage_da_data *mpd, - struct buffer_head *head, - struct buffer_head *bh, - ext4_lblk_t lblk) +/* + * mpage_process_page_bufs - submit page buffers for IO or add them to extent + * + * @mpd - extent of blocks for mapping + * @head - the first buffer in the page + * @bh - buffer we should start processing from + * @lblk - logical number of the block in the file corresponding to @bh + * + * Walk through page buffers from @bh upto @head (exclusive) and either submit + * the page for IO if all buffers in this page were mapped and there's no + * accumulated extent of buffers to map or add buffers in the page to the + * extent of buffers to map. The function returns 1 if the caller can continue + * by processing the next page, 0 if it should stop adding buffers to the + * extent to map because we cannot extend it anymore. It can also return value + * < 0 in case of error during IO submission. + */ +static int mpage_process_page_bufs(struct mpage_da_data *mpd, + struct buffer_head *head, + struct buffer_head *bh, + ext4_lblk_t lblk) { struct inode *inode = mpd->inode; + int err; ext4_lblk_t blocks = (i_size_read(inode) + (1 << inode->i_blkbits) - 1) >> inode->i_blkbits; @@ -1963,32 +2000,18 @@ static bool add_page_bufs_to_extent(struct mpage_da_data *mpd, if (lblk >= blocks || !mpage_add_bh_to_extent(mpd, lblk, bh)) { /* Found extent to map? */ if (mpd->map.m_len) - return false; + return 0; /* Everything mapped so far and we hit EOF */ - return true; + break; } } while (lblk++, (bh = bh->b_this_page) != head); - return true; -} - -static int mpage_submit_page(struct mpage_da_data *mpd, struct page *page) -{ - int len; - loff_t size = i_size_read(mpd->inode); - int err; - - BUG_ON(page->index != mpd->first_page); - if (page->index == size >> PAGE_CACHE_SHIFT) - len = size & ~PAGE_CACHE_MASK; - else - len = PAGE_CACHE_SIZE; - clear_page_dirty_for_io(page); - err = ext4_bio_write_page(&mpd->io_submit, page, len, mpd->wbc); - if (!err) - mpd->wbc->nr_to_write--; - mpd->first_page++; - - return err; + /* So far everything mapped? Submit the page for IO. */ + if (mpd->map.m_len == 0) { + err = mpage_submit_page(mpd, head->b_page); + if (err < 0) + return err; + } + return lblk < blocks; } /* @@ -2012,8 +2035,6 @@ static int mpage_map_and_submit_buffers(struct mpage_da_data *mpd) struct inode *inode = mpd->inode; struct buffer_head *head, *bh; int bpp_bits = PAGE_CACHE_SHIFT - inode->i_blkbits; - ext4_lblk_t blocks = (i_size_read(inode) + (1 << inode->i_blkbits) - 1) - >> inode->i_blkbits; pgoff_t start, end; ext4_lblk_t lblk; sector_t pblock; @@ -2048,18 +2069,26 @@ static int mpage_map_and_submit_buffers(struct mpage_da_data *mpd) */ mpd->map.m_len = 0; mpd->map.m_flags = 0; - add_page_bufs_to_extent(mpd, head, bh, - lblk); + /* + * FIXME: If dioread_nolock supports + * blocksize < pagesize, we need to make + * sure we add size mapped so far to + * io_end->size as the following call + * can submit the page for IO. + */ + err = mpage_process_page_bufs(mpd, head, + bh, lblk); pagevec_release(&pvec); - return 0; + if (err > 0) + err = 0; + return err; } if (buffer_delay(bh)) { clear_buffer_delay(bh); bh->b_blocknr = pblock++; } clear_buffer_unwritten(bh); - } while (++lblk < blocks && - (bh = bh->b_this_page) != head); + } while (lblk++, (bh = bh->b_this_page) != head); /* * FIXME: This is going to break if dioread_nolock @@ -2328,14 +2357,10 @@ static int mpage_prepare_extent_to_map(struct mpage_da_data *mpd) lblk = ((ext4_lblk_t)page->index) << (PAGE_CACHE_SHIFT - blkbits); head = page_buffers(page); - if (!add_page_bufs_to_extent(mpd, head, head, lblk)) + err = mpage_process_page_bufs(mpd, head, head, lblk); + if (err <= 0) goto out; - /* So far everything mapped? Submit the page for IO. */ - if (mpd->map.m_len == 0) { - err = mpage_submit_page(mpd, page); - if (err < 0) - goto out; - } + err = 0; /* * Accumulated enough dirty pages? This doesn't apply |