* Delayed allocation stuff
*/
-static void ext4_da_block_invalidatepages(struct mpage_da_data *mpd);
-
-/*
- * mpage_da_submit_io - walks through extent of pages and try to write
- * them with writepage() call back
- *
- * @mpd->inode: inode
- * @mpd->first_page: first page of the extent
- * @mpd->next_page: page after the last page of the extent
- *
- * By the time mpage_da_submit_io() is called we expect all blocks
- * to be allocated. this may be wrong if allocation failed.
- *
- * As pages are already locked by write_cache_pages(), we can't use it
- */
-static int mpage_da_submit_io(struct mpage_da_data *mpd,
- struct ext4_map_blocks *map)
-{
- struct pagevec pvec;
- unsigned long index, end;
- int ret = 0, err, nr_pages, i;
- struct inode *inode = mpd->inode;
- struct address_space *mapping = inode->i_mapping;
- loff_t size = i_size_read(inode);
- unsigned int len, block_start;
- struct buffer_head *bh, *page_bufs = NULL;
- sector_t pblock = 0, cur_logical = 0;
- struct ext4_io_submit io_submit;
-
- BUG_ON(mpd->next_page <= mpd->first_page);
- ext4_io_submit_init(&io_submit, mpd->wbc);
- io_submit.io_end = ext4_init_io_end(inode, GFP_NOFS);
- if (!io_submit.io_end) {
- ext4_da_block_invalidatepages(mpd);
- return -ENOMEM;
- }
+struct mpage_da_data {
+ struct inode *inode;
+ struct writeback_control *wbc;
+ pgoff_t first_page; /* The first page to write */
+ pgoff_t next_page; /* Current page to examine */
+ pgoff_t last_page; /* Last page to examine */
/*
- * We need to start from the first_page to the next_page - 1
- * to make sure we also write the mapped dirty buffer_heads.
- * If we look at mpd->b_blocknr we would only be looking
- * at the currently mapped buffer_heads.
+ * Extent to map - this can be after first_page because that can be
+ * fully mapped. We somewhat abuse m_flags to store whether the extent
+ * is delalloc or unwritten.
*/
- index = mpd->first_page;
- end = mpd->next_page - 1;
-
- pagevec_init(&pvec, 0);
- while (index <= end) {
- nr_pages = pagevec_lookup(&pvec, mapping, index, PAGEVEC_SIZE);
- if (nr_pages == 0)
- break;
- for (i = 0; i < nr_pages; i++) {
- int skip_page = 0;
- struct page *page = pvec.pages[i];
-
- index = page->index;
- if (index > end)
- break;
-
- if (index == size >> PAGE_CACHE_SHIFT)
- len = size & ~PAGE_CACHE_MASK;
- else
- len = PAGE_CACHE_SIZE;
- if (map) {
- cur_logical = index << (PAGE_CACHE_SHIFT -
- inode->i_blkbits);
- pblock = map->m_pblk + (cur_logical -
- map->m_lblk);
- }
- index++;
-
- BUG_ON(!PageLocked(page));
- BUG_ON(PageWriteback(page));
-
- bh = page_bufs = page_buffers(page);
- block_start = 0;
- do {
- if (map && (cur_logical >= map->m_lblk) &&
- (cur_logical <= (map->m_lblk +
- (map->m_len - 1)))) {
- if (buffer_delay(bh)) {
- clear_buffer_delay(bh);
- bh->b_blocknr = pblock;
- }
- if (buffer_unwritten(bh) ||
- buffer_mapped(bh))
- BUG_ON(bh->b_blocknr != pblock);
- if (map->m_flags & EXT4_MAP_UNINIT)
- set_buffer_uninit(bh);
- clear_buffer_unwritten(bh);
- }
-
- /*
- * skip page if block allocation undone and
- * block is dirty
- */
- if (ext4_bh_delay_or_unwritten(NULL, bh))
- skip_page = 1;
- bh = bh->b_this_page;
- block_start += bh->b_size;
- cur_logical++;
- pblock++;
- } while (bh != page_bufs);
-
- if (skip_page) {
- unlock_page(page);
- continue;
- }
-
- clear_page_dirty_for_io(page);
- err = ext4_bio_write_page(&io_submit, page, len,
- mpd->wbc);
- if (!err)
- mpd->pages_written++;
- /*
- * In error case, we have to continue because
- * remaining pages are still locked
- */
- if (ret == 0)
- ret = err;
- }
- pagevec_release(&pvec);
- }
- ext4_io_submit(&io_submit);
- /* Drop io_end reference we got from init */
- ext4_put_io_end_defer(io_submit.io_end);
- return ret;
-}
+ struct ext4_map_blocks map;
+ struct ext4_io_submit io_submit; /* IO submission data */
+};
-static void ext4_da_block_invalidatepages(struct mpage_da_data *mpd)
+static void mpage_release_unused_pages(struct mpage_da_data *mpd,
+ bool invalidate)
{
int nr_pages, i;
pgoff_t index, end;
struct pagevec pvec;
struct inode *inode = mpd->inode;
struct address_space *mapping = inode->i_mapping;
- ext4_lblk_t start, last;
+
+ /* This is necessary when next_page == 0. */
+ if (mpd->first_page >= mpd->next_page)
+ return;
index = mpd->first_page;
end = mpd->next_page - 1;
-
- start = index << (PAGE_CACHE_SHIFT - inode->i_blkbits);
- last = end << (PAGE_CACHE_SHIFT - inode->i_blkbits);
- ext4_es_remove_extent(inode, start, last - start + 1);
+ if (invalidate) {
+ ext4_lblk_t start, last;
+ start = index << (PAGE_CACHE_SHIFT - inode->i_blkbits);
+ last = end << (PAGE_CACHE_SHIFT - inode->i_blkbits);
+ ext4_es_remove_extent(inode, start, last - start + 1);
+ }
pagevec_init(&pvec, 0);
while (index <= end) {
break;
BUG_ON(!PageLocked(page));
BUG_ON(PageWriteback(page));
- block_invalidatepage(page, 0, PAGE_CACHE_SIZE);
- ClearPageUptodate(page);
+ if (invalidate) {
+ block_invalidatepage(page, 0, PAGE_CACHE_SIZE);
+ ClearPageUptodate(page);
+ }
unlock_page(page);
}
index = pvec.pages[nr_pages - 1]->index + 1;
pagevec_release(&pvec);
}
- return;
}
static void ext4_print_free_blocks(struct inode *inode)
return;
}
-/*
- * mpage_da_map_and_submit - go through given space, map them
- * if necessary, and then submit them for I/O
- *
- * @mpd - bh describing space
- *
- * The function skips space we know is already mapped to disk blocks.
- *
- */
-static void mpage_da_map_and_submit(struct mpage_da_data *mpd)
-{
- int err, blks, get_blocks_flags;
- struct ext4_map_blocks map, *mapp = NULL;
- sector_t next = mpd->b_blocknr;
- unsigned max_blocks = mpd->b_size >> mpd->inode->i_blkbits;
- loff_t disksize = EXT4_I(mpd->inode)->i_disksize;
- handle_t *handle = NULL;
-
- /*
- * If the blocks are mapped already, or we couldn't accumulate
- * any blocks, then proceed immediately to the submission stage.
- */
- if ((mpd->b_size == 0) ||
- ((mpd->b_state & (1 << BH_Mapped)) &&
- !(mpd->b_state & (1 << BH_Delay)) &&
- !(mpd->b_state & (1 << BH_Unwritten))))
- goto submit_io;
-
- handle = ext4_journal_current_handle();
- BUG_ON(!handle);
-
- /*
- * Call ext4_map_blocks() to allocate any delayed allocation
- * blocks, or to convert an uninitialized extent to be
- * initialized (in the case where we have written into
- * one or more preallocated blocks).
- *
- * We pass in the magic EXT4_GET_BLOCKS_DELALLOC_RESERVE to
- * indicate that we are on the delayed allocation path. This
- * affects functions in many different parts of the allocation
- * call path. This flag exists primarily because we don't
- * want to change *many* call functions, so ext4_map_blocks()
- * will set the EXT4_STATE_DELALLOC_RESERVED flag once the
- * inode's allocation semaphore is taken.
- *
- * If the blocks in questions were delalloc blocks, set
- * EXT4_GET_BLOCKS_DELALLOC_RESERVE so the delalloc accounting
- * variables are updated after the blocks have been allocated.
- */
- map.m_lblk = next;
- map.m_len = max_blocks;
- /*
- * We're in delalloc path and it is possible that we're going to
- * need more metadata blocks than previously reserved. However
- * we must not fail because we're in writeback and there is
- * nothing we can do about it so it might result in data loss.
- * So use reserved blocks to allocate metadata if possible.
- */
- get_blocks_flags = EXT4_GET_BLOCKS_CREATE |
- EXT4_GET_BLOCKS_METADATA_NOFAIL;
- if (ext4_should_dioread_nolock(mpd->inode))
- get_blocks_flags |= EXT4_GET_BLOCKS_IO_CREATE_EXT;
- if (mpd->b_state & (1 << BH_Delay))
- get_blocks_flags |= EXT4_GET_BLOCKS_DELALLOC_RESERVE;
-
-
- blks = ext4_map_blocks(handle, mpd->inode, &map, get_blocks_flags);
- if (blks < 0) {
- struct super_block *sb = mpd->inode->i_sb;
-
- err = blks;
- /*
- * If get block returns EAGAIN or ENOSPC and there
- * appears to be free blocks we will just let
- * mpage_da_submit_io() unlock all of the pages.
- */
- if (err == -EAGAIN)
- goto submit_io;
-
- if (err == -ENOSPC && ext4_count_free_clusters(sb)) {
- mpd->retval = err;
- goto submit_io;
- }
-
- /*
- * get block failure will cause us to loop in
- * writepages, because a_ops->writepage won't be able
- * to make progress. The page will be redirtied by
- * writepage and writepages will again try to write
- * the same.
- */
- if (!(EXT4_SB(sb)->s_mount_flags & EXT4_MF_FS_ABORTED)) {
- ext4_msg(sb, KERN_CRIT,
- "delayed block allocation failed for inode %lu "
- "at logical offset %llu with max blocks %zd "
- "with error %d", mpd->inode->i_ino,
- (unsigned long long) next,
- mpd->b_size >> mpd->inode->i_blkbits, err);
- ext4_msg(sb, KERN_CRIT,
- "This should not happen!! Data will be lost");
- if (err == -ENOSPC)
- ext4_print_free_blocks(mpd->inode);
- }
- /* invalidate all the pages */
- ext4_da_block_invalidatepages(mpd);
-
- /* Mark this page range as having been completed */
- mpd->io_done = 1;
- return;
- }
- BUG_ON(blks == 0);
-
- mapp = ↦
- if (map.m_flags & EXT4_MAP_NEW) {
- struct block_device *bdev = mpd->inode->i_sb->s_bdev;
- int i;
-
- for (i = 0; i < map.m_len; i++)
- unmap_underlying_metadata(bdev, map.m_pblk + i);
- }
-
- /*
- * Update on-disk size along with block allocation.
- */
- disksize = ((loff_t) next + blks) << mpd->inode->i_blkbits;
- if (disksize > i_size_read(mpd->inode))
- disksize = i_size_read(mpd->inode);
- if (disksize > EXT4_I(mpd->inode)->i_disksize) {
- ext4_update_i_disksize(mpd->inode, disksize);
- err = ext4_mark_inode_dirty(handle, mpd->inode);
- if (err)
- ext4_error(mpd->inode->i_sb,
- "Failed to mark inode %lu dirty",
- mpd->inode->i_ino);
- }
-
-submit_io:
- mpage_da_submit_io(mpd, mapp);
- mpd->io_done = 1;
-}
-
-#define BH_FLAGS ((1 << BH_Uptodate) | (1 << BH_Mapped) | \
- (1 << BH_Delay) | (1 << BH_Unwritten))
-
-/*
- * mpage_add_bh_to_extent - try to add one more block to extent of blocks
- *
- * @mpd->lbh - extent of blocks
- * @logical - logical number of the block in the file
- * @b_state - b_state of the buffer head added
- *
- * the function is used to collect contig. blocks in same state
- */
-static void mpage_add_bh_to_extent(struct mpage_da_data *mpd, sector_t logical,
- unsigned long b_state)
-{
- sector_t next;
- int blkbits = mpd->inode->i_blkbits;
- int nrblocks = mpd->b_size >> blkbits;
-
- /*
- * XXX Don't go larger than mballoc is willing to allocate
- * This is a stopgap solution. We eventually need to fold
- * mpage_da_submit_io() into this function and then call
- * ext4_map_blocks() multiple times in a loop
- */
- if (nrblocks >= (8*1024*1024 >> blkbits))
- goto flush_it;
-
- /* check if the reserved journal credits might overflow */
- if (!ext4_test_inode_flag(mpd->inode, EXT4_INODE_EXTENTS)) {
- if (nrblocks >= EXT4_MAX_TRANS_DATA) {
- /*
- * With non-extent format we are limited by the journal
- * credit available. Total credit needed to insert
- * nrblocks contiguous blocks is dependent on the
- * nrblocks. So limit nrblocks.
- */
- goto flush_it;
- }
- }
- /*
- * First block in the extent
- */
- if (mpd->b_size == 0) {
- mpd->b_blocknr = logical;
- mpd->b_size = 1 << blkbits;
- mpd->b_state = b_state & BH_FLAGS;
- return;
- }
-
- next = mpd->b_blocknr + nrblocks;
- /*
- * Can we merge the block to our big extent?
- */
- if (logical == next && (b_state & BH_FLAGS) == mpd->b_state) {
- mpd->b_size += 1 << blkbits;
- return;
- }
-
-flush_it:
- /*
- * We couldn't merge the block to our extent, so we
- * need to flush current extent and start new one
- */
- mpage_da_map_and_submit(mpd);
- return;
-}
-
static int ext4_bh_delay_or_unwritten(handle_t *handle, struct buffer_head *bh)
{
return (buffer_delay(bh) || buffer_unwritten(bh)) && buffer_dirty(bh);
return ret;
}
+#define BH_FLAGS ((1 << BH_Unwritten) | (1 << BH_Delay))
+
/*
* mballoc gives us at most this number of blocks...
* XXX: That seems to be only a limitation of ext4_mb_normalize_request().
#define MAX_WRITEPAGES_EXTENT_LEN 2048
/*
+ * mpage_add_bh_to_extent - try to add bh to extent of blocks to map
+ *
+ * @mpd - extent of blocks
+ * @lblk - logical number of the block in the file
+ * @b_state - b_state of the buffer head added
+ *
+ * the function is used to collect contig. blocks in same state
+ */
+static int mpage_add_bh_to_extent(struct mpage_da_data *mpd, ext4_lblk_t lblk,
+ unsigned long b_state)
+{
+ struct ext4_map_blocks *map = &mpd->map;
+
+ /* Don't go larger than mballoc is willing to allocate */
+ if (map->m_len >= MAX_WRITEPAGES_EXTENT_LEN)
+ return 0;
+
+ /* First block in the extent? */
+ if (map->m_len == 0) {
+ map->m_lblk = lblk;
+ map->m_len = 1;
+ map->m_flags = b_state & BH_FLAGS;
+ return 1;
+ }
+
+ /* Can we merge the block to our big extent? */
+ if (lblk == map->m_lblk + map->m_len &&
+ (b_state & BH_FLAGS) == map->m_flags) {
+ map->m_len++;
+ return 1;
+ }
+ return 0;
+}
+
+static bool add_page_bufs_to_extent(struct mpage_da_data *mpd,
+ struct buffer_head *head,
+ struct buffer_head *bh,
+ ext4_lblk_t lblk)
+{
+ struct inode *inode = mpd->inode;
+ ext4_lblk_t blocks = (i_size_read(inode) + (1 << inode->i_blkbits) - 1)
+ >> inode->i_blkbits;
+
+ do {
+ BUG_ON(buffer_locked(bh));
+
+ if (!buffer_dirty(bh) || !buffer_mapped(bh) ||
+ (!buffer_delay(bh) && !buffer_unwritten(bh)) ||
+ lblk >= blocks) {
+ /* Found extent to map? */
+ if (mpd->map.m_len)
+ return false;
+ if (lblk >= blocks)
+ return true;
+ continue;
+ }
+ if (!mpage_add_bh_to_extent(mpd, lblk, bh->b_state))
+ return false;
+ } 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;
+}
+
+/*
+ * mpage_map_buffers - update buffers corresponding to changed extent and
+ * submit fully mapped pages for IO
+ *
+ * @mpd - description of extent to map, on return next extent to map
+ *
+ * Scan buffers corresponding to changed extent (we expect corresponding pages
+ * to be already locked) and update buffer state according to new extent state.
+ * We map delalloc buffers to their physical location, clear unwritten bits,
+ * and mark buffers as uninit when we perform writes to uninitialized extents
+ * and do extent conversion after IO is finished. If the last page is not fully
+ * mapped, we update @map to the next extent in the last page that needs
+ * mapping. Otherwise we submit the page for IO.
+ */
+static int mpage_map_and_submit_buffers(struct mpage_da_data *mpd)
+{
+ struct pagevec pvec;
+ int nr_pages, i;
+ 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;
+ int err;
+
+ start = mpd->map.m_lblk >> bpp_bits;
+ end = (mpd->map.m_lblk + mpd->map.m_len - 1) >> bpp_bits;
+ lblk = start << bpp_bits;
+ pblock = mpd->map.m_pblk;
+
+ pagevec_init(&pvec, 0);
+ while (start <= end) {
+ nr_pages = pagevec_lookup(&pvec, inode->i_mapping, start,
+ PAGEVEC_SIZE);
+ if (nr_pages == 0)
+ break;
+ for (i = 0; i < nr_pages; i++) {
+ struct page *page = pvec.pages[i];
+
+ if (page->index > end)
+ break;
+ /* Upto 'end' pages must be contiguous */
+ BUG_ON(page->index != start);
+ bh = head = page_buffers(page);
+ do {
+ if (lblk < mpd->map.m_lblk)
+ continue;
+ if (lblk >= mpd->map.m_lblk + mpd->map.m_len) {
+ /*
+ * Buffer after end of mapped extent.
+ * Find next buffer in the page to map.
+ */
+ mpd->map.m_len = 0;
+ mpd->map.m_flags = 0;
+ add_page_bufs_to_extent(mpd, head, bh,
+ lblk);
+ pagevec_release(&pvec);
+ return 0;
+ }
+ if (buffer_delay(bh)) {
+ clear_buffer_delay(bh);
+ bh->b_blocknr = pblock++;
+ }
+ if (mpd->map.m_flags & EXT4_MAP_UNINIT)
+ set_buffer_uninit(bh);
+ clear_buffer_unwritten(bh);
+ } while (++lblk < blocks &&
+ (bh = bh->b_this_page) != head);
+
+ /*
+ * FIXME: This is going to break if dioread_nolock
+ * supports blocksize < pagesize as we will try to
+ * convert potentially unmapped parts of inode.
+ */
+ mpd->io_submit.io_end->size += PAGE_CACHE_SIZE;
+ /* Page fully mapped - let IO run! */
+ err = mpage_submit_page(mpd, page);
+ if (err < 0) {
+ pagevec_release(&pvec);
+ return err;
+ }
+ start++;
+ }
+ pagevec_release(&pvec);
+ }
+ /* Extent fully mapped and matches with page boundary. We are done. */
+ mpd->map.m_len = 0;
+ mpd->map.m_flags = 0;
+ return 0;
+}
+
+static int mpage_map_one_extent(handle_t *handle, struct mpage_da_data *mpd)
+{
+ struct inode *inode = mpd->inode;
+ struct ext4_map_blocks *map = &mpd->map;
+ int get_blocks_flags;
+ int err;
+
+ trace_ext4_da_write_pages_extent(inode, map);
+ /*
+ * Call ext4_map_blocks() to allocate any delayed allocation blocks, or
+ * to convert an uninitialized extent to be initialized (in the case
+ * where we have written into one or more preallocated blocks). It is
+ * possible that we're going to need more metadata blocks than
+ * previously reserved. However we must not fail because we're in
+ * writeback and there is nothing we can do about it so it might result
+ * in data loss. So use reserved blocks to allocate metadata if
+ * possible.
+ *
+ * We pass in the magic EXT4_GET_BLOCKS_DELALLOC_RESERVE if the blocks
+ * in question are delalloc blocks. This affects functions in many
+ * different parts of the allocation call path. This flag exists
+ * primarily because we don't want to change *many* call functions, so
+ * ext4_map_blocks() will set the EXT4_STATE_DELALLOC_RESERVED flag
+ * once the inode's allocation semaphore is taken.
+ */
+ get_blocks_flags = EXT4_GET_BLOCKS_CREATE |
+ EXT4_GET_BLOCKS_METADATA_NOFAIL;
+ if (ext4_should_dioread_nolock(inode))
+ get_blocks_flags |= EXT4_GET_BLOCKS_IO_CREATE_EXT;
+ if (map->m_flags & (1 << BH_Delay))
+ get_blocks_flags |= EXT4_GET_BLOCKS_DELALLOC_RESERVE;
+
+ err = ext4_map_blocks(handle, inode, map, get_blocks_flags);
+ if (err < 0)
+ return err;
+
+ BUG_ON(map->m_len == 0);
+ if (map->m_flags & EXT4_MAP_NEW) {
+ struct block_device *bdev = inode->i_sb->s_bdev;
+ int i;
+
+ for (i = 0; i < map->m_len; i++)
+ unmap_underlying_metadata(bdev, map->m_pblk + i);
+ }
+ return 0;
+}
+
+/*
+ * mpage_map_and_submit_extent - map extent starting at mpd->lblk of length
+ * mpd->len and submit pages underlying it for IO
+ *
+ * @handle - handle for journal operations
+ * @mpd - extent to map
+ *
+ * The function maps extent starting at mpd->lblk of length mpd->len. If it is
+ * delayed, blocks are allocated, if it is unwritten, we may need to convert
+ * them to initialized or split the described range from larger unwritten
+ * extent. Note that we need not map all the described range since allocation
+ * can return less blocks or the range is covered by more unwritten extents. We
+ * cannot map more because we are limited by reserved transaction credits. On
+ * the other hand we always make sure that the last touched page is fully
+ * mapped so that it can be written out (and thus forward progress is
+ * guaranteed). After mapping we submit all mapped pages for IO.
+ */
+static int mpage_map_and_submit_extent(handle_t *handle,
+ struct mpage_da_data *mpd)
+{
+ struct inode *inode = mpd->inode;
+ struct ext4_map_blocks *map = &mpd->map;
+ int err;
+ loff_t disksize;
+
+ mpd->io_submit.io_end->offset =
+ ((loff_t)map->m_lblk) << inode->i_blkbits;
+ while (map->m_len) {
+ err = mpage_map_one_extent(handle, mpd);
+ if (err < 0) {
+ struct super_block *sb = inode->i_sb;
+
+ /*
+ * Need to commit transaction to free blocks. Let upper
+ * layers sort it out.
+ */
+ if (err == -ENOSPC && ext4_count_free_clusters(sb))
+ return -ENOSPC;
+
+ if (!(EXT4_SB(sb)->s_mount_flags & EXT4_MF_FS_ABORTED)) {
+ ext4_msg(sb, KERN_CRIT,
+ "Delayed block allocation failed for "
+ "inode %lu at logical offset %llu with"
+ " max blocks %u with error %d",
+ inode->i_ino,
+ (unsigned long long)map->m_lblk,
+ (unsigned)map->m_len, err);
+ ext4_msg(sb, KERN_CRIT,
+ "This should not happen!! Data will "
+ "be lost\n");
+ if (err == -ENOSPC)
+ ext4_print_free_blocks(inode);
+ }
+ /* invalidate all the pages */
+ mpage_release_unused_pages(mpd, true);
+ return err;
+ }
+ /*
+ * Update buffer state, submit mapped pages, and get us new
+ * extent to map
+ */
+ err = mpage_map_and_submit_buffers(mpd);
+ if (err < 0)
+ return err;
+ }
+
+ /* Update on-disk size after IO is submitted */
+ disksize = ((loff_t)mpd->first_page) << PAGE_CACHE_SHIFT;
+ if (disksize > i_size_read(inode))
+ disksize = i_size_read(inode);
+ if (disksize > EXT4_I(inode)->i_disksize) {
+ int err2;
+
+ ext4_update_i_disksize(inode, disksize);
+ err2 = ext4_mark_inode_dirty(handle, inode);
+ if (err2)
+ ext4_error(inode->i_sb,
+ "Failed to mark inode %lu dirty",
+ inode->i_ino);
+ if (!err)
+ err = err2;
+ }
+ return err;
+}
+
+/*
* Calculate the total number of credits to reserve for one writepages
* iteration. This is called from ext4_da_writepages(). We map an extent of
* upto MAX_WRITEPAGES_EXTENT_LEN blocks and then we go on and finish mapping
}
/*
- * write_cache_pages_da - walk the list of dirty pages of the given
- * address space and accumulate pages that need writing, and call
- * mpage_da_map_and_submit to map a single contiguous memory region
- * and then write them.
+ * mpage_prepare_extent_to_map - find & lock contiguous range of dirty pages
+ * and underlying extent to map
+ *
+ * @mpd - where to look for pages
+ *
+ * Walk dirty pages in the mapping. If they are fully mapped, submit them for
+ * IO immediately. When we find a page which isn't mapped we start accumulating
+ * extent of buffers underlying these pages that needs mapping (formed by
+ * either delayed or unwritten buffers). We also lock the pages containing
+ * these buffers. The extent found is returned in @mpd structure (starting at
+ * mpd->lblk with length mpd->len blocks).
+ *
+ * Note that this function can attach bios to one io_end structure which are
+ * neither logically nor physically contiguous. Although it may seem as an
+ * unnecessary complication, it is actually inevitable in blocksize < pagesize
+ * case as we need to track IO to all buffers underlying a page in one io_end.
*/
-static int write_cache_pages_da(handle_t *handle,
- struct address_space *mapping,
- struct writeback_control *wbc,
- struct mpage_da_data *mpd,
- pgoff_t *done_index)
+static int mpage_prepare_extent_to_map(struct mpage_da_data *mpd)
{
- struct buffer_head *bh, *head;
- struct inode *inode = mapping->host;
- struct pagevec pvec;
- unsigned int nr_pages;
- sector_t logical;
- pgoff_t index, end;
- long nr_to_write = wbc->nr_to_write;
- int i, tag, ret = 0;
-
- memset(mpd, 0, sizeof(struct mpage_da_data));
- mpd->wbc = wbc;
- mpd->inode = inode;
- pagevec_init(&pvec, 0);
- index = wbc->range_start >> PAGE_CACHE_SHIFT;
- end = wbc->range_end >> PAGE_CACHE_SHIFT;
+ struct address_space *mapping = mpd->inode->i_mapping;
+ struct pagevec pvec;
+ unsigned int nr_pages;
+ pgoff_t index = mpd->first_page;
+ pgoff_t end = mpd->last_page;
+ int tag;
+ int i, err = 0;
+ int blkbits = mpd->inode->i_blkbits;
+ ext4_lblk_t lblk;
+ struct buffer_head *head;
- if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
+ if (mpd->wbc->sync_mode == WB_SYNC_ALL || mpd->wbc->tagged_writepages)
tag = PAGECACHE_TAG_TOWRITE;
else
tag = PAGECACHE_TAG_DIRTY;
- *done_index = index;
+ pagevec_init(&pvec, 0);
+ mpd->map.m_len = 0;
+ mpd->next_page = index;
while (index <= end) {
nr_pages = pagevec_lookup_tag(&pvec, mapping, &index, tag,
min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1);
if (nr_pages == 0)
- return 0;
+ goto out;
for (i = 0; i < nr_pages; i++) {
struct page *page = pvec.pages[i];
if (page->index > end)
goto out;
- *done_index = page->index + 1;
-
- /*
- * If we can't merge this page, and we have
- * accumulated an contiguous region, write it
- */
- if ((mpd->next_page != page->index) &&
- (mpd->next_page != mpd->first_page)) {
- mpage_da_map_and_submit(mpd);
- goto ret_extent_tail;
- }
+ /* If we can't merge this page, we are done. */
+ if (mpd->map.m_len > 0 && mpd->next_page != page->index)
+ goto out;
lock_page(page);
-
/*
- * If the page is no longer dirty, or its
- * mapping no longer corresponds to inode we
- * are writing (which means it has been
- * truncated or invalidated), or the page is
- * already under writeback and we are not
- * doing a data integrity writeback, skip the page
+ * If the page is no longer dirty, or its mapping no
+ * longer corresponds to inode we are writing (which
+ * means it has been truncated or invalidated), or the
+ * page is already under writeback and we are not doing
+ * a data integrity writeback, skip the page
*/
if (!PageDirty(page) ||
(PageWriteback(page) &&
- (wbc->sync_mode == WB_SYNC_NONE)) ||
+ (mpd->wbc->sync_mode == WB_SYNC_NONE)) ||
unlikely(page->mapping != mapping)) {
unlock_page(page);
continue;
wait_on_page_writeback(page);
BUG_ON(PageWriteback(page));
- /*
- * If we have inline data and arrive here, it means that
- * we will soon create the block for the 1st page, so
- * we'd better clear the inline data here.
- */
- if (ext4_has_inline_data(inode)) {
- BUG_ON(ext4_test_inode_state(inode,
- EXT4_STATE_MAY_INLINE_DATA));
- ext4_destroy_inline_data(handle, inode);
- }
-
- if (mpd->next_page != page->index)
+ if (mpd->map.m_len == 0)
mpd->first_page = page->index;
mpd->next_page = page->index + 1;
- logical = (sector_t) page->index <<
- (PAGE_CACHE_SHIFT - inode->i_blkbits);
-
/* Add all dirty buffers to mpd */
+ lblk = ((ext4_lblk_t)page->index) <<
+ (PAGE_CACHE_SHIFT - blkbits);
head = page_buffers(page);
- bh = head;
- do {
- BUG_ON(buffer_locked(bh));
- /*
- * We need to try to allocate unmapped blocks
- * in the same page. Otherwise we won't make
- * progress with the page in ext4_writepage
- */
- if (ext4_bh_delay_or_unwritten(NULL, bh)) {
- mpage_add_bh_to_extent(mpd, logical,
- bh->b_state);
- if (mpd->io_done)
- goto ret_extent_tail;
- } else if (buffer_dirty(bh) &&
- buffer_mapped(bh)) {
- /*
- * mapped dirty buffer. We need to
- * update the b_state because we look
- * at b_state in mpage_da_map_blocks.
- * We don't update b_size because if we
- * find an unmapped buffer_head later
- * we need to use the b_state flag of
- * that buffer_head.
- */
- if (mpd->b_size == 0)
- mpd->b_state =
- bh->b_state & BH_FLAGS;
- }
- logical++;
- } while ((bh = bh->b_this_page) != head);
-
- if (nr_to_write > 0) {
- nr_to_write--;
- if (nr_to_write == 0 &&
- wbc->sync_mode == WB_SYNC_NONE)
- /*
- * We stop writing back only if we are
- * not doing integrity sync. In case of
- * integrity sync we have to keep going
- * because someone may be concurrently
- * dirtying pages, and we might have
- * synced a lot of newly appeared dirty
- * pages, but have not synced all of the
- * old dirty pages.
- */
+ if (!add_page_bufs_to_extent(mpd, head, head, lblk))
+ 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;
}
+
+ /*
+ * Accumulated enough dirty pages? This doesn't apply
+ * to WB_SYNC_ALL mode. For integrity sync we have to
+ * keep going because someone may be concurrently
+ * dirtying pages, and we might have synced a lot of
+ * newly appeared dirty pages, but have not synced all
+ * of the old dirty pages.
+ */
+ if (mpd->wbc->sync_mode == WB_SYNC_NONE &&
+ mpd->next_page - mpd->first_page >=
+ mpd->wbc->nr_to_write)
+ goto out;
}
pagevec_release(&pvec);
cond_resched();
}
return 0;
-ret_extent_tail:
- ret = MPAGE_DA_EXTENT_TAIL;
out:
pagevec_release(&pvec);
- cond_resched();
- return ret;
+ return err;
}
-
static int ext4_da_writepages(struct address_space *mapping,
struct writeback_control *wbc)
{
- pgoff_t index;
+ pgoff_t writeback_index = 0;
+ long nr_to_write = wbc->nr_to_write;
int range_whole = 0;
+ int cycled = 1;
handle_t *handle = NULL;
struct mpage_da_data mpd;
struct inode *inode = mapping->host;
- int pages_written = 0;
- int range_cyclic, cycled = 1, io_done = 0;
int needed_blocks, ret = 0;
- loff_t range_start = wbc->range_start;
struct ext4_sb_info *sbi = EXT4_SB(mapping->host->i_sb);
- pgoff_t done_index = 0;
- pgoff_t end;
+ bool done;
struct blk_plug plug;
trace_ext4_da_writepages(inode, wbc);
if (unlikely(sbi->s_mount_flags & EXT4_MF_FS_ABORTED))
return -EROFS;
+ /*
+ * If we have inline data and arrive here, it means that
+ * we will soon create the block for the 1st page, so
+ * we'd better clear the inline data here.
+ */
+ if (ext4_has_inline_data(inode)) {
+ /* Just inode will be modified... */
+ handle = ext4_journal_start(inode, EXT4_HT_INODE, 1);
+ if (IS_ERR(handle)) {
+ ret = PTR_ERR(handle);
+ goto out_writepages;
+ }
+ BUG_ON(ext4_test_inode_state(inode,
+ EXT4_STATE_MAY_INLINE_DATA));
+ ext4_destroy_inline_data(handle, inode);
+ ext4_journal_stop(handle);
+ }
+
if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
range_whole = 1;
- range_cyclic = wbc->range_cyclic;
if (wbc->range_cyclic) {
- index = mapping->writeback_index;
- if (index)
+ writeback_index = mapping->writeback_index;
+ if (writeback_index)
cycled = 0;
- wbc->range_start = index << PAGE_CACHE_SHIFT;
- wbc->range_end = LLONG_MAX;
- wbc->range_cyclic = 0;
- end = -1;
+ mpd.first_page = writeback_index;
+ mpd.last_page = -1;
} else {
- index = wbc->range_start >> PAGE_CACHE_SHIFT;
- end = wbc->range_end >> PAGE_CACHE_SHIFT;
+ mpd.first_page = wbc->range_start >> PAGE_CACHE_SHIFT;
+ mpd.last_page = wbc->range_end >> PAGE_CACHE_SHIFT;
}
+ mpd.inode = inode;
+ mpd.wbc = wbc;
+ ext4_io_submit_init(&mpd.io_submit, wbc);
retry:
if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
- tag_pages_for_writeback(mapping, index, end);
-
+ tag_pages_for_writeback(mapping, mpd.first_page, mpd.last_page);
+ done = false;
blk_start_plug(&plug);
- while (!ret && wbc->nr_to_write > 0) {
+ while (!done && mpd.first_page <= mpd.last_page) {
+ /* For each extent of pages we use new io_end */
+ mpd.io_submit.io_end = ext4_init_io_end(inode, GFP_KERNEL);
+ if (!mpd.io_submit.io_end) {
+ ret = -ENOMEM;
+ break;
+ }
/*
- * we insert one extent at a time. So we need
- * credit needed for single extent allocation.
- * journalled mode is currently not supported
- * by delalloc
+ * We have two constraints: We find one extent to map and we
+ * must always write out whole page (makes a difference when
+ * blocksize < pagesize) so that we don't block on IO when we
+ * try to write out the rest of the page. Journalled mode is
+ * not supported by delalloc.
*/
BUG_ON(ext4_should_journal_data(inode));
needed_blocks = ext4_da_writepages_trans_blocks(inode);
- /* start a new transaction*/
+ /* start a new transaction */
handle = ext4_journal_start(inode, EXT4_HT_WRITE_PAGE,
needed_blocks);
if (IS_ERR(handle)) {
ext4_msg(inode->i_sb, KERN_CRIT, "%s: jbd2_start: "
"%ld pages, ino %lu; err %d", __func__,
wbc->nr_to_write, inode->i_ino, ret);
- blk_finish_plug(&plug);
- goto out_writepages;
+ /* Release allocated io_end */
+ ext4_put_io_end(mpd.io_submit.io_end);
+ break;
}
- /*
- * Now call write_cache_pages_da() to find the next
- * contiguous region of logical blocks that need
- * blocks to be allocated by ext4 and submit them.
- */
- ret = write_cache_pages_da(handle, mapping,
- wbc, &mpd, &done_index);
- /*
- * If we have a contiguous extent of pages and we
- * haven't done the I/O yet, map the blocks and submit
- * them for I/O.
- */
- if (!mpd.io_done && mpd.next_page != mpd.first_page) {
- mpage_da_map_and_submit(&mpd);
- ret = MPAGE_DA_EXTENT_TAIL;
+ trace_ext4_da_write_pages(inode, mpd.first_page, mpd.wbc);
+ ret = mpage_prepare_extent_to_map(&mpd);
+ if (!ret) {
+ if (mpd.map.m_len)
+ ret = mpage_map_and_submit_extent(handle, &mpd);
+ else {
+ /*
+ * We scanned the whole range (or exhausted
+ * nr_to_write), submitted what was mapped and
+ * didn't find anything needing mapping. We are
+ * done.
+ */
+ done = true;
+ }
}
- trace_ext4_da_write_pages(inode, &mpd);
- wbc->nr_to_write -= mpd.pages_written;
-
ext4_journal_stop(handle);
-
- if ((mpd.retval == -ENOSPC) && sbi->s_journal) {
- /* commit the transaction which would
+ /* Submit prepared bio */
+ ext4_io_submit(&mpd.io_submit);
+ /* Unlock pages we didn't use */
+ mpage_release_unused_pages(&mpd, false);
+ /* Drop our io_end reference we got from init */
+ ext4_put_io_end(mpd.io_submit.io_end);
+
+ if (ret == -ENOSPC && sbi->s_journal) {
+ /*
+ * Commit the transaction which would
* free blocks released in the transaction
* and try again
*/
jbd2_journal_force_commit_nested(sbi->s_journal);
ret = 0;
- } else if (ret == MPAGE_DA_EXTENT_TAIL) {
- /*
- * Got one extent now try with rest of the pages.
- * If mpd.retval is set -EIO, journal is aborted.
- * So we don't need to write any more.
- */
- pages_written += mpd.pages_written;
- ret = mpd.retval;
- io_done = 1;
- } else if (wbc->nr_to_write)
- /*
- * There is no more writeout needed
- * or we requested for a noblocking writeout
- * and we found the device congested
- */
+ continue;
+ }
+ /* Fatal error - ENOMEM, EIO... */
+ if (ret)
break;
}
blk_finish_plug(&plug);
- if (!io_done && !cycled) {
+ if (!ret && !cycled) {
cycled = 1;
- index = 0;
- wbc->range_start = index << PAGE_CACHE_SHIFT;
- wbc->range_end = mapping->writeback_index - 1;
+ mpd.last_page = writeback_index - 1;
+ mpd.first_page = 0;
goto retry;
}
/* Update index */
- wbc->range_cyclic = range_cyclic;
if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
/*
- * set the writeback_index so that range_cyclic
+ * Set the writeback_index so that range_cyclic
* mode will write it back later
*/
- mapping->writeback_index = done_index;
+ mapping->writeback_index = mpd.first_page;
out_writepages:
- wbc->range_start = range_start;
- trace_ext4_da_writepages_result(inode, wbc, ret, pages_written);
+ trace_ext4_da_writepages_result(inode, wbc, ret,
+ nr_to_write - wbc->nr_to_write);
return ret;
}
projects / kernel / kernel-generic.git / commitdiff