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Diffstat (limited to 'fs/ext4/inode.c')
-rw-r--r--fs/ext4/inode.c107
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