#include <linux/pagevec.h>
#include <linux/writeback.h>
+/* flags for direct write completions */
+#define XFS_DIO_FLAG_UNWRITTEN (1 << 0)
+#define XFS_DIO_FLAG_APPEND (1 << 1)
+
+/*
+ * structure owned by writepages passed to individual writepage calls
+ */
+struct xfs_writepage_ctx {
+ struct xfs_bmbt_irec imap;
+ bool imap_valid;
+ unsigned int io_type;
+ struct xfs_ioend *ioend;
+ sector_t last_block;
+};
+
void
xfs_count_page_state(
struct page *page,
struct xfs_inode *ip = XFS_I(ioend->io_inode);
int error = 0;
- if (XFS_FORCED_SHUTDOWN(ip->i_mount)) {
+ /*
+ * Set an error if the mount has shut down and proceed with end I/O
+ * processing so it can perform whatever cleanups are necessary.
+ */
+ if (XFS_FORCED_SHUTDOWN(ip->i_mount))
ioend->io_error = -EIO;
- goto done;
- }
/*
* For unwritten extents we need to issue transactions to convert a
*/
atomic_set(&ioend->io_remaining, 1);
ioend->io_error = 0;
- ioend->io_list = NULL;
+ INIT_LIST_HEAD(&ioend->io_list);
ioend->io_type = type;
ioend->io_inode = inode;
ioend->io_buffer_head = NULL;
struct inode *inode,
loff_t offset,
struct xfs_bmbt_irec *imap,
- int type,
- int nonblocking)
+ int type)
{
struct xfs_inode *ip = XFS_I(inode);
struct xfs_mount *mp = ip->i_mount;
if (type == XFS_IO_UNWRITTEN)
bmapi_flags |= XFS_BMAPI_IGSTATE;
- if (!xfs_ilock_nowait(ip, XFS_ILOCK_SHARED)) {
- if (nonblocking)
- return -EAGAIN;
- xfs_ilock(ip, XFS_ILOCK_SHARED);
- }
-
+ xfs_ilock(ip, XFS_ILOCK_SHARED);
ASSERT(ip->i_d.di_format != XFS_DINODE_FMT_BTREE ||
(ip->i_df.if_flags & XFS_IFEXTENTS));
ASSERT(offset <= mp->m_super->s_maxbytes);
return 0;
}
-STATIC int
+STATIC bool
xfs_imap_valid(
struct inode *inode,
struct xfs_bmbt_irec *imap,
STATIC void
xfs_start_page_writeback(
struct page *page,
- int clear_dirty,
- int buffers)
+ int clear_dirty)
{
ASSERT(PageLocked(page));
ASSERT(!PageWriteback(page));
set_page_writeback_keepwrite(page);
unlock_page(page);
-
- /* If no buffers on the page are to be written, finish it here */
- if (!buffers)
- end_page_writeback(page);
}
static inline int xfs_bio_add_buffer(struct bio *bio, struct buffer_head *bh)
}
/*
- * Submit all of the bios for all of the ioends we have saved up, covering the
- * initial writepage page and also any probed pages.
- *
- * Because we may have multiple ioends spanning a page, we need to start
- * writeback on all the buffers before we submit them for I/O. If we mark the
- * buffers as we got, then we can end up with a page that only has buffers
- * marked async write and I/O complete on can occur before we mark the other
- * buffers async write.
- *
- * The end result of this is that we trip a bug in end_page_writeback() because
- * we call it twice for the one page as the code in end_buffer_async_write()
- * assumes that all buffers on the page are started at the same time.
- *
- * The fix is two passes across the ioend list - one to start writeback on the
- * buffer_heads, and then submit them for I/O on the second pass.
+ * Submit all of the bios for an ioend. We are only passed a single ioend at a
+ * time; the caller is responsible for chaining prior to submission.
*
* If @fail is non-zero, it means that we have a situation where some part of
* the submission process has failed after we have marked paged for writeback
* and unlocked them. In this situation, we need to fail the ioend chain rather
* than submit it to IO. This typically only happens on a filesystem shutdown.
*/
-STATIC void
+STATIC int
xfs_submit_ioend(
struct writeback_control *wbc,
xfs_ioend_t *ioend,
- int fail)
+ int status)
{
- xfs_ioend_t *head = ioend;
- xfs_ioend_t *next;
struct buffer_head *bh;
struct bio *bio;
sector_t lastblock = 0;
- /* Pass 1 - start writeback */
- do {
- next = ioend->io_list;
- for (bh = ioend->io_buffer_head; bh; bh = bh->b_private)
- xfs_start_buffer_writeback(bh);
- } while ((ioend = next) != NULL);
+ /* Reserve log space if we might write beyond the on-disk inode size. */
+ if (!status &&
+ ioend->io_type != XFS_IO_UNWRITTEN && xfs_ioend_is_append(ioend))
+ status = xfs_setfilesize_trans_alloc(ioend);
+ /*
+ * If we are failing the IO now, just mark the ioend with an
+ * error and finish it. This will run IO completion immediately
+ * as there is only one reference to the ioend at this point in
+ * time.
+ */
+ if (status) {
+ ioend->io_error = status;
+ xfs_finish_ioend(ioend);
+ return status;
+ }
- /* Pass 2 - submit I/O */
- ioend = head;
- do {
- next = ioend->io_list;
- bio = NULL;
+ bio = NULL;
+ for (bh = ioend->io_buffer_head; bh; bh = bh->b_private) {
- /*
- * If we are failing the IO now, just mark the ioend with an
- * error and finish it. This will run IO completion immediately
- * as there is only one reference to the ioend at this point in
- * time.
- */
- if (fail) {
- ioend->io_error = fail;
- xfs_finish_ioend(ioend);
- continue;
+ if (!bio) {
+retry:
+ bio = xfs_alloc_ioend_bio(bh);
+ } else if (bh->b_blocknr != lastblock + 1) {
+ xfs_submit_ioend_bio(wbc, ioend, bio);
+ goto retry;
}
- for (bh = ioend->io_buffer_head; bh; bh = bh->b_private) {
-
- if (!bio) {
- retry:
- bio = xfs_alloc_ioend_bio(bh);
- } else if (bh->b_blocknr != lastblock + 1) {
- xfs_submit_ioend_bio(wbc, ioend, bio);
- goto retry;
- }
-
- if (xfs_bio_add_buffer(bio, bh) != bh->b_size) {
- xfs_submit_ioend_bio(wbc, ioend, bio);
- goto retry;
- }
-
- lastblock = bh->b_blocknr;
- }
- if (bio)
+ if (xfs_bio_add_buffer(bio, bh) != bh->b_size) {
xfs_submit_ioend_bio(wbc, ioend, bio);
- xfs_finish_ioend(ioend);
- } while ((ioend = next) != NULL);
-}
-
-/*
- * Cancel submission of all buffer_heads so far in this endio.
- * Toss the endio too. Only ever called for the initial page
- * in a writepage request, so only ever one page.
- */
-STATIC void
-xfs_cancel_ioend(
- xfs_ioend_t *ioend)
-{
- xfs_ioend_t *next;
- struct buffer_head *bh, *next_bh;
-
- do {
- next = ioend->io_list;
- bh = ioend->io_buffer_head;
- do {
- next_bh = bh->b_private;
- clear_buffer_async_write(bh);
- /*
- * The unwritten flag is cleared when added to the
- * ioend. We're not submitting for I/O so mark the
- * buffer unwritten again for next time around.
- */
- if (ioend->io_type == XFS_IO_UNWRITTEN)
- set_buffer_unwritten(bh);
- unlock_buffer(bh);
- } while ((bh = next_bh) != NULL);
+ goto retry;
+ }
- mempool_free(ioend, xfs_ioend_pool);
- } while ((ioend = next) != NULL);
+ lastblock = bh->b_blocknr;
+ }
+ if (bio)
+ xfs_submit_ioend_bio(wbc, ioend, bio);
+ xfs_finish_ioend(ioend);
+ return 0;
}
/*
* Test to see if we've been building up a completion structure for
* earlier buffers -- if so, we try to append to this ioend if we
* can, otherwise we finish off any current ioend and start another.
- * Return true if we've finished the given ioend.
+ * Return the ioend we finished off so that the caller can submit it
+ * once it has finished processing the dirty page.
*/
STATIC void
xfs_add_to_ioend(
struct inode *inode,
struct buffer_head *bh,
xfs_off_t offset,
- unsigned int type,
- xfs_ioend_t **result,
- int need_ioend)
+ struct xfs_writepage_ctx *wpc,
+ struct list_head *iolist)
{
- xfs_ioend_t *ioend = *result;
-
- if (!ioend || need_ioend || type != ioend->io_type) {
- xfs_ioend_t *previous = *result;
-
- ioend = xfs_alloc_ioend(inode, type);
- ioend->io_offset = offset;
- ioend->io_buffer_head = bh;
- ioend->io_buffer_tail = bh;
- if (previous)
- previous->io_list = ioend;
- *result = ioend;
+ if (!wpc->ioend || wpc->io_type != wpc->ioend->io_type ||
+ bh->b_blocknr != wpc->last_block + 1 ||
+ offset != wpc->ioend->io_offset + wpc->ioend->io_size) {
+ struct xfs_ioend *new;
+
+ if (wpc->ioend)
+ list_add(&wpc->ioend->io_list, iolist);
+
+ new = xfs_alloc_ioend(inode, wpc->io_type);
+ new->io_offset = offset;
+ new->io_buffer_head = bh;
+ new->io_buffer_tail = bh;
+ wpc->ioend = new;
} else {
- ioend->io_buffer_tail->b_private = bh;
- ioend->io_buffer_tail = bh;
+ wpc->ioend->io_buffer_tail->b_private = bh;
+ wpc->ioend->io_buffer_tail = bh;
}
bh->b_private = NULL;
- ioend->io_size += bh->b_size;
+ wpc->ioend->io_size += bh->b_size;
+ wpc->last_block = bh->b_blocknr;
+ xfs_start_buffer_writeback(bh);
}
STATIC void
return false;
}
-/*
- * Allocate & map buffers for page given the extent map. Write it out.
- * except for the original page of a writepage, this is called on
- * delalloc/unwritten pages only, for the original page it is possible
- * that the page has no mapping at all.
- */
-STATIC int
-xfs_convert_page(
- struct inode *inode,
- struct page *page,
- loff_t tindex,
- struct xfs_bmbt_irec *imap,
- xfs_ioend_t **ioendp,
- struct writeback_control *wbc)
-{
- struct buffer_head *bh, *head;
- xfs_off_t end_offset;
- unsigned long p_offset;
- unsigned int type;
- int len, page_dirty;
- int count = 0, done = 0, uptodate = 1;
- xfs_off_t offset = page_offset(page);
-
- if (page->index != tindex)
- goto fail;
- if (!trylock_page(page))
- goto fail;
- if (PageWriteback(page))
- goto fail_unlock_page;
- if (page->mapping != inode->i_mapping)
- goto fail_unlock_page;
- if (!xfs_check_page_type(page, (*ioendp)->io_type, false))
- goto fail_unlock_page;
-
- /*
- * page_dirty is initially a count of buffers on the page before
- * EOF and is decremented as we move each into a cleanable state.
- *
- * Derivation:
- *
- * End offset is the highest offset that this page should represent.
- * If we are on the last page, (end_offset & (PAGE_CACHE_SIZE - 1))
- * will evaluate non-zero and be less than PAGE_CACHE_SIZE and
- * hence give us the correct page_dirty count. On any other page,
- * it will be zero and in that case we need page_dirty to be the
- * count of buffers on the page.
- */
- end_offset = min_t(unsigned long long,
- (xfs_off_t)(page->index + 1) << PAGE_CACHE_SHIFT,
- i_size_read(inode));
-
- /*
- * If the current map does not span the entire page we are about to try
- * to write, then give up. The only way we can write a page that spans
- * multiple mappings in a single writeback iteration is via the
- * xfs_vm_writepage() function. Data integrity writeback requires the
- * entire page to be written in a single attempt, otherwise the part of
- * the page we don't write here doesn't get written as part of the data
- * integrity sync.
- *
- * For normal writeback, we also don't attempt to write partial pages
- * here as it simply means that write_cache_pages() will see it under
- * writeback and ignore the page until some point in the future, at
- * which time this will be the only page in the file that needs
- * writeback. Hence for more optimal IO patterns, we should always
- * avoid partial page writeback due to multiple mappings on a page here.
- */
- if (!xfs_imap_valid(inode, imap, end_offset))
- goto fail_unlock_page;
-
- len = 1 << inode->i_blkbits;
- p_offset = min_t(unsigned long, end_offset & (PAGE_CACHE_SIZE - 1),
- PAGE_CACHE_SIZE);
- p_offset = p_offset ? roundup(p_offset, len) : PAGE_CACHE_SIZE;
- page_dirty = p_offset / len;
-
- /*
- * The moment we find a buffer that doesn't match our current type
- * specification or can't be written, abort the loop and start
- * writeback. As per the above xfs_imap_valid() check, only
- * xfs_vm_writepage() can handle partial page writeback fully - we are
- * limited here to the buffers that are contiguous with the current
- * ioend, and hence a buffer we can't write breaks that contiguity and
- * we have to defer the rest of the IO to xfs_vm_writepage().
- */
- bh = head = page_buffers(page);
- do {
- if (offset >= end_offset)
- break;
- if (!buffer_uptodate(bh))
- uptodate = 0;
- if (!(PageUptodate(page) || buffer_uptodate(bh))) {
- done = 1;
- break;
- }
-
- if (buffer_unwritten(bh) || buffer_delay(bh) ||
- buffer_mapped(bh)) {
- if (buffer_unwritten(bh))
- type = XFS_IO_UNWRITTEN;
- else if (buffer_delay(bh))
- type = XFS_IO_DELALLOC;
- else
- type = XFS_IO_OVERWRITE;
-
- /*
- * imap should always be valid because of the above
- * partial page end_offset check on the imap.
- */
- ASSERT(xfs_imap_valid(inode, imap, offset));
-
- lock_buffer(bh);
- if (type != XFS_IO_OVERWRITE)
- xfs_map_at_offset(inode, bh, imap, offset);
- xfs_add_to_ioend(inode, bh, offset, type,
- ioendp, done);
-
- page_dirty--;
- count++;
- } else {
- done = 1;
- break;
- }
- } while (offset += len, (bh = bh->b_this_page) != head);
-
- if (uptodate && bh == head)
- SetPageUptodate(page);
-
- if (count) {
- if (--wbc->nr_to_write <= 0 &&
- wbc->sync_mode == WB_SYNC_NONE)
- done = 1;
- }
- xfs_start_page_writeback(page, !page_dirty, count);
-
- return done;
- fail_unlock_page:
- unlock_page(page);
- fail:
- return 1;
-}
-
-/*
- * Convert & write out a cluster of pages in the same extent as defined
- * by mp and following the start page.
- */
-STATIC void
-xfs_cluster_write(
- struct inode *inode,
- pgoff_t tindex,
- struct xfs_bmbt_irec *imap,
- xfs_ioend_t **ioendp,
- struct writeback_control *wbc,
- pgoff_t tlast)
-{
- struct pagevec pvec;
- int done = 0, i;
-
- pagevec_init(&pvec, 0);
- while (!done && tindex <= tlast) {
- unsigned len = min_t(pgoff_t, PAGEVEC_SIZE, tlast - tindex + 1);
-
- if (!pagevec_lookup(&pvec, inode->i_mapping, tindex, len))
- break;
-
- for (i = 0; i < pagevec_count(&pvec); i++) {
- done = xfs_convert_page(inode, pvec.pages[i], tindex++,
- imap, ioendp, wbc);
- if (done)
- break;
- }
-
- pagevec_release(&pvec);
- cond_resched();
- }
-}
-
STATIC void
xfs_vm_invalidatepage(
struct page *page,
return;
}
+/*
+ * We implement an immediate ioend submission policy here to avoid needing to
+ * chain multiple ioends and hence nest mempool allocations which can violate
+ * forward progress guarantees we need to provide. The current ioend we are
+ * adding buffers to is cached on the writepage context, and if the new buffer
+ * does not append to the cached ioend it will create a new ioend and cache that
+ * instead.
+ *
+ * If a new ioend is created and cached, the old ioend is returned and queued
+ * locally for submission once the entire page is processed or an error has been
+ * detected. While ioends are submitted immediately after they are completed,
+ * batching optimisations are provided by higher level block plugging.
+ *
+ * At the end of a writeback pass, there will be a cached ioend remaining on the
+ * writepage context that the caller will need to submit.
+ */
+static int
+xfs_writepage_map(
+ struct xfs_writepage_ctx *wpc,
+ struct writeback_control *wbc,
+ struct inode *inode,
+ struct page *page,
+ loff_t offset,
+ __uint64_t end_offset)
+{
+ LIST_HEAD(submit_list);
+ struct xfs_ioend *ioend, *next;
+ struct buffer_head *bh, *head;
+ ssize_t len = 1 << inode->i_blkbits;
+ int error = 0;
+ int count = 0;
+ int uptodate = 1;
+
+ bh = head = page_buffers(page);
+ offset = page_offset(page);
+ do {
+ if (offset >= end_offset)
+ break;
+ if (!buffer_uptodate(bh))
+ uptodate = 0;
+
+ /*
+ * set_page_dirty dirties all buffers in a page, independent
+ * of their state. The dirty state however is entirely
+ * meaningless for holes (!mapped && uptodate), so skip
+ * buffers covering holes here.
+ */
+ if (!buffer_mapped(bh) && buffer_uptodate(bh)) {
+ wpc->imap_valid = false;
+ continue;
+ }
+
+ if (buffer_unwritten(bh)) {
+ if (wpc->io_type != XFS_IO_UNWRITTEN) {
+ wpc->io_type = XFS_IO_UNWRITTEN;
+ wpc->imap_valid = false;
+ }
+ } else if (buffer_delay(bh)) {
+ if (wpc->io_type != XFS_IO_DELALLOC) {
+ wpc->io_type = XFS_IO_DELALLOC;
+ wpc->imap_valid = false;
+ }
+ } else if (buffer_uptodate(bh)) {
+ if (wpc->io_type != XFS_IO_OVERWRITE) {
+ wpc->io_type = XFS_IO_OVERWRITE;
+ wpc->imap_valid = false;
+ }
+ } else {
+ if (PageUptodate(page))
+ ASSERT(buffer_mapped(bh));
+ /*
+ * This buffer is not uptodate and will not be
+ * written to disk. Ensure that we will put any
+ * subsequent writeable buffers into a new
+ * ioend.
+ */
+ wpc->imap_valid = false;
+ continue;
+ }
+
+ if (wpc->imap_valid)
+ wpc->imap_valid = xfs_imap_valid(inode, &wpc->imap,
+ offset);
+ if (!wpc->imap_valid) {
+ error = xfs_map_blocks(inode, offset, &wpc->imap,
+ wpc->io_type);
+ if (error)
+ goto out;
+ wpc->imap_valid = xfs_imap_valid(inode, &wpc->imap,
+ offset);
+ }
+ if (wpc->imap_valid) {
+ lock_buffer(bh);
+ if (wpc->io_type != XFS_IO_OVERWRITE)
+ xfs_map_at_offset(inode, bh, &wpc->imap, offset);
+ xfs_add_to_ioend(inode, bh, offset, wpc, &submit_list);
+ count++;
+ }
+
+ } while (offset += len, ((bh = bh->b_this_page) != head));
+
+ if (uptodate && bh == head)
+ SetPageUptodate(page);
+
+ ASSERT(wpc->ioend || list_empty(&submit_list));
+
+out:
+ /*
+ * On error, we have to fail the ioend here because we have locked
+ * buffers in the ioend. If we don't do this, we'll deadlock
+ * invalidating the page as that tries to lock the buffers on the page.
+ * Also, because we may have set pages under writeback, we have to make
+ * sure we run IO completion to mark the error state of the IO
+ * appropriately, so we can't cancel the ioend directly here. That means
+ * we have to mark this page as under writeback if we included any
+ * buffers from it in the ioend chain so that completion treats it
+ * correctly.
+ *
+ * If we didn't include the page in the ioend, the on error we can
+ * simply discard and unlock it as there are no other users of the page
+ * or it's buffers right now. The caller will still need to trigger
+ * submission of outstanding ioends on the writepage context so they are
+ * treated correctly on error.
+ */
+ if (count) {
+ xfs_start_page_writeback(page, !error);
+
+ /*
+ * Preserve the original error if there was one, otherwise catch
+ * submission errors here and propagate into subsequent ioend
+ * submissions.
+ */
+ list_for_each_entry_safe(ioend, next, &submit_list, io_list) {
+ int error2;
+
+ list_del_init(&ioend->io_list);
+ error2 = xfs_submit_ioend(wbc, ioend, error);
+ if (error2 && !error)
+ error = error2;
+ }
+ } else if (error) {
+ xfs_aops_discard_page(page);
+ ClearPageUptodate(page);
+ unlock_page(page);
+ } else {
+ /*
+ * We can end up here with no error and nothing to write if we
+ * race with a partial page truncate on a sub-page block sized
+ * filesystem. In that case we need to mark the page clean.
+ */
+ xfs_start_page_writeback(page, 1);
+ end_page_writeback(page);
+ }
+
+ mapping_set_error(page->mapping, error);
+ return error;
+}
+
/*
* Write out a dirty page.
*
* For any other dirty buffer heads on the page we should flush them.
*/
STATIC int
-xfs_vm_writepage(
+xfs_do_writepage(
struct page *page,
- struct writeback_control *wbc)
+ struct writeback_control *wbc,
+ void *data)
{
+ struct xfs_writepage_ctx *wpc = data;
struct inode *inode = page->mapping->host;
- struct buffer_head *bh, *head;
- struct xfs_bmbt_irec imap;
- xfs_ioend_t *ioend = NULL, *iohead = NULL;
loff_t offset;
- unsigned int type;
__uint64_t end_offset;
- pgoff_t end_index, last_index;
- ssize_t len;
- int err, imap_valid = 0, uptodate = 1;
- int count = 0;
- int nonblocking = 0;
+ pgoff_t end_index;
trace_xfs_writepage(inode, page, 0, 0);
if (WARN_ON_ONCE(current->flags & PF_FSTRANS))
goto redirty;
- /* Is this page beyond the end of the file? */
- offset = i_size_read(inode);
- end_index = offset >> PAGE_CACHE_SHIFT;
- last_index = (offset - 1) >> PAGE_CACHE_SHIFT;
-
/*
+ * Is this page beyond the end of the file?
+ *
* The page index is less than the end_index, adjust the end_offset
* to the highest offset that this page should represent.
* -----------------------------------------------------
* | desired writeback range | see else |
* ---------------------------------^------------------|
*/
+ offset = i_size_read(inode);
+ end_index = offset >> PAGE_CACHE_SHIFT;
if (page->index < end_index)
end_offset = (xfs_off_t)(page->index + 1) << PAGE_CACHE_SHIFT;
else {
end_offset = offset;
}
- len = 1 << inode->i_blkbits;
-
- bh = head = page_buffers(page);
- offset = page_offset(page);
- type = XFS_IO_OVERWRITE;
-
- if (wbc->sync_mode == WB_SYNC_NONE)
- nonblocking = 1;
-
- do {
- int new_ioend = 0;
-
- if (offset >= end_offset)
- break;
- if (!buffer_uptodate(bh))
- uptodate = 0;
-
- /*
- * set_page_dirty dirties all buffers in a page, independent
- * of their state. The dirty state however is entirely
- * meaningless for holes (!mapped && uptodate), so skip
- * buffers covering holes here.
- */
- if (!buffer_mapped(bh) && buffer_uptodate(bh)) {
- imap_valid = 0;
- continue;
- }
-
- if (buffer_unwritten(bh)) {
- if (type != XFS_IO_UNWRITTEN) {
- type = XFS_IO_UNWRITTEN;
- imap_valid = 0;
- }
- } else if (buffer_delay(bh)) {
- if (type != XFS_IO_DELALLOC) {
- type = XFS_IO_DELALLOC;
- imap_valid = 0;
- }
- } else if (buffer_uptodate(bh)) {
- if (type != XFS_IO_OVERWRITE) {
- type = XFS_IO_OVERWRITE;
- imap_valid = 0;
- }
- } else {
- if (PageUptodate(page))
- ASSERT(buffer_mapped(bh));
- /*
- * This buffer is not uptodate and will not be
- * written to disk. Ensure that we will put any
- * subsequent writeable buffers into a new
- * ioend.
- */
- imap_valid = 0;
- continue;
- }
-
- if (imap_valid)
- imap_valid = xfs_imap_valid(inode, &imap, offset);
- if (!imap_valid) {
- /*
- * If we didn't have a valid mapping then we need to
- * put the new mapping into a separate ioend structure.
- * This ensures non-contiguous extents always have
- * separate ioends, which is particularly important
- * for unwritten extent conversion at I/O completion
- * time.
- */
- new_ioend = 1;
- err = xfs_map_blocks(inode, offset, &imap, type,
- nonblocking);
- if (err)
- goto error;
- imap_valid = xfs_imap_valid(inode, &imap, offset);
- }
- if (imap_valid) {
- lock_buffer(bh);
- if (type != XFS_IO_OVERWRITE)
- xfs_map_at_offset(inode, bh, &imap, offset);
- xfs_add_to_ioend(inode, bh, offset, type, &ioend,
- new_ioend);
- count++;
- }
-
- if (!iohead)
- iohead = ioend;
-
- } while (offset += len, ((bh = bh->b_this_page) != head));
-
- if (uptodate && bh == head)
- SetPageUptodate(page);
-
- xfs_start_page_writeback(page, 1, count);
-
- /* if there is no IO to be submitted for this page, we are done */
- if (!ioend)
- return 0;
-
- ASSERT(iohead);
-
- /*
- * Any errors from this point onwards need tobe reported through the IO
- * completion path as we have marked the initial page as under writeback
- * and unlocked it.
- */
- if (imap_valid) {
- xfs_off_t end_index;
-
- end_index = imap.br_startoff + imap.br_blockcount;
-
- /* to bytes */
- end_index <<= inode->i_blkbits;
-
- /* to pages */
- end_index = (end_index - 1) >> PAGE_CACHE_SHIFT;
-
- /* check against file size */
- if (end_index > last_index)
- end_index = last_index;
-
- xfs_cluster_write(inode, page->index + 1, &imap, &ioend,
- wbc, end_index);
- }
-
-
- /*
- * Reserve log space if we might write beyond the on-disk inode size.
- */
- err = 0;
- if (ioend->io_type != XFS_IO_UNWRITTEN && xfs_ioend_is_append(ioend))
- err = xfs_setfilesize_trans_alloc(ioend);
-
- xfs_submit_ioend(wbc, iohead, err);
-
- return 0;
-
-error:
- if (iohead)
- xfs_cancel_ioend(iohead);
-
- if (err == -EAGAIN)
- goto redirty;
-
- xfs_aops_discard_page(page);
- ClearPageUptodate(page);
- unlock_page(page);
- return err;
+ return xfs_writepage_map(wpc, wbc, inode, page, offset, end_offset);
redirty:
redirty_page_for_writepage(wbc, page);
return 0;
}
+STATIC int
+xfs_vm_writepage(
+ struct page *page,
+ struct writeback_control *wbc)
+{
+ struct xfs_writepage_ctx wpc = {
+ .io_type = XFS_IO_INVALID,
+ };
+ int ret;
+
+ ret = xfs_do_writepage(page, wbc, &wpc);
+ if (wpc.ioend)
+ ret = xfs_submit_ioend(wbc, wpc.ioend, ret);
+ return ret;
+}
+
STATIC int
xfs_vm_writepages(
struct address_space *mapping,
struct writeback_control *wbc)
{
+ struct xfs_writepage_ctx wpc = {
+ .io_type = XFS_IO_INVALID,
+ };
+ int ret;
+
xfs_iflags_clear(XFS_I(mapping->host), XFS_ITRUNCATED);
- return generic_writepages(mapping, wbc);
+ ret = write_cache_pages(mapping, wbc, xfs_do_writepage, &wpc);
+ if (wpc.ioend)
+ ret = xfs_submit_ioend(wbc, wpc.ioend, ret);
+ return ret;
}
/*
}
/*
- * When we map a DIO buffer, we may need to attach an ioend that describes the
- * type of write IO we are doing. This passes to the completion function the
- * operations it needs to perform. If the mapping is for an overwrite wholly
- * within the EOF then we don't need an ioend and so we don't allocate one.
- * This avoids the unnecessary overhead of allocating and freeing ioends for
- * workloads that don't require transactions on IO completion.
- *
- * If we get multiple mappings in a single IO, we might be mapping different
- * types. But because the direct IO can only have a single private pointer, we
- * need to ensure that:
- *
- * a) i) the ioend spans the entire region of unwritten mappings; or
- * ii) the ioend spans all the mappings that cross or are beyond EOF; and
- * b) if it contains unwritten extents, it is *permanently* marked as such
- *
- * We could do this by chaining ioends like buffered IO does, but we only
- * actually get one IO completion callback from the direct IO, and that spans
- * the entire IO regardless of how many mappings and IOs are needed to complete
- * the DIO. There is only going to be one reference to the ioend and its life
- * cycle is constrained by the DIO completion code. hence we don't need
- * reference counting here.
+ * When we map a DIO buffer, we may need to pass flags to
+ * xfs_end_io_direct_write to tell it what kind of write IO we are doing.
*
* Note that for DIO, an IO to the highest supported file block offset (i.e.
* 2^63 - 1FSB bytes) will result in the offset + count overflowing a signed 64
* extending the file size. We won't know for sure until IO completion is run
* and the actual max write offset is communicated to the IO completion
* routine.
- *
- * For DAX page faults, we are preparing to never see unwritten extents here,
- * nor should we ever extend the inode size. Hence we will soon have nothing to
- * do here for this case, ensuring we don't have to provide an IO completion
- * callback to free an ioend that we don't actually need for a fault into the
- * page at offset (2^63 - 1FSB) bytes.
*/
-
static void
xfs_map_direct(
struct inode *inode,
struct buffer_head *bh_result,
struct xfs_bmbt_irec *imap,
- xfs_off_t offset,
- bool dax_fault)
+ xfs_off_t offset)
{
- struct xfs_ioend *ioend;
+ uintptr_t *flags = (uintptr_t *)&bh_result->b_private;
xfs_off_t size = bh_result->b_size;
- int type;
-
- if (ISUNWRITTEN(imap))
- type = XFS_IO_UNWRITTEN;
- else
- type = XFS_IO_OVERWRITE;
-
- trace_xfs_gbmap_direct(XFS_I(inode), offset, size, type, imap);
- if (dax_fault) {
- ASSERT(type == XFS_IO_OVERWRITE);
- trace_xfs_gbmap_direct_none(XFS_I(inode), offset, size, type,
- imap);
- return;
- }
+ trace_xfs_get_blocks_map_direct(XFS_I(inode), offset, size,
+ ISUNWRITTEN(imap) ? XFS_IO_UNWRITTEN : XFS_IO_OVERWRITE, imap);
- if (bh_result->b_private) {
- ioend = bh_result->b_private;
- ASSERT(ioend->io_size > 0);
- ASSERT(offset >= ioend->io_offset);
- if (offset + size > ioend->io_offset + ioend->io_size)
- ioend->io_size = offset - ioend->io_offset + size;
-
- if (type == XFS_IO_UNWRITTEN && type != ioend->io_type)
- ioend->io_type = XFS_IO_UNWRITTEN;
-
- trace_xfs_gbmap_direct_update(XFS_I(inode), ioend->io_offset,
- ioend->io_size, ioend->io_type,
- imap);
- } else if (type == XFS_IO_UNWRITTEN ||
- offset + size > i_size_read(inode) ||
- offset + size < 0) {
- ioend = xfs_alloc_ioend(inode, type);
- ioend->io_offset = offset;
- ioend->io_size = size;
-
- bh_result->b_private = ioend;
+ if (ISUNWRITTEN(imap)) {
+ *flags |= XFS_DIO_FLAG_UNWRITTEN;
+ set_buffer_defer_completion(bh_result);
+ } else if (offset + size > i_size_read(inode) || offset + size < 0) {
+ *flags |= XFS_DIO_FLAG_APPEND;
set_buffer_defer_completion(bh_result);
-
- trace_xfs_gbmap_direct_new(XFS_I(inode), offset, size, type,
- imap);
- } else {
- trace_xfs_gbmap_direct_none(XFS_I(inode), offset, size, type,
- imap);
}
}
if (ISUNWRITTEN(&imap))
set_buffer_unwritten(bh_result);
/* direct IO needs special help */
- if (create && direct)
- xfs_map_direct(inode, bh_result, &imap, offset,
- dax_fault);
+ if (create && direct) {
+ if (dax_fault)
+ ASSERT(!ISUNWRITTEN(&imap));
+ else
+ xfs_map_direct(inode, bh_result, &imap, offset);
+ }
}
/*
return __xfs_get_blocks(inode, iblock, bh_result, create, true, true);
}
-static void
-__xfs_end_io_direct_write(
- struct inode *inode,
- struct xfs_ioend *ioend,
+/*
+ * Complete a direct I/O write request.
+ *
+ * xfs_map_direct passes us some flags in the private data to tell us what to
+ * do. If no flags are set, then the write IO is an overwrite wholly within
+ * the existing allocated file size and so there is nothing for us to do.
+ *
+ * Note that in this case the completion can be called in interrupt context,
+ * whereas if we have flags set we will always be called in task context
+ * (i.e. from a workqueue).
+ */
+STATIC int
+xfs_end_io_direct_write(
+ struct kiocb *iocb,
loff_t offset,
- ssize_t size)
+ ssize_t size,
+ void *private)
{
- struct xfs_mount *mp = XFS_I(inode)->i_mount;
+ struct inode *inode = file_inode(iocb->ki_filp);
+ struct xfs_inode *ip = XFS_I(inode);
+ struct xfs_mount *mp = ip->i_mount;
+ uintptr_t flags = (uintptr_t)private;
+ int error = 0;
- if (XFS_FORCED_SHUTDOWN(mp) || ioend->io_error)
- goto out_end_io;
+ trace_xfs_end_io_direct_write(ip, offset, size);
- /*
- * dio completion end_io functions are only called on writes if more
- * than 0 bytes was written.
- */
- ASSERT(size > 0);
+ if (XFS_FORCED_SHUTDOWN(mp))
+ return -EIO;
- /*
- * The ioend only maps whole blocks, while the IO may be sector aligned.
- * Hence the ioend offset/size may not match the IO offset/size exactly.
- * Because we don't map overwrites within EOF into the ioend, the offset
- * may not match, but only if the endio spans EOF. Either way, write
- * the IO sizes into the ioend so that completion processing does the
- * right thing.
- */
- ASSERT(offset + size <= ioend->io_offset + ioend->io_size);
- ioend->io_size = size;
- ioend->io_offset = offset;
+ if (size <= 0)
+ return size;
/*
- * The ioend tells us whether we are doing unwritten extent conversion
+ * The flags tell us whether we are doing unwritten extent conversions
* or an append transaction that updates the on-disk file size. These
* cases are the only cases where we should *potentially* be needing
* to update the VFS inode size.
- *
+ */
+ if (flags == 0) {
+ ASSERT(offset + size <= i_size_read(inode));
+ return 0;
+ }
+
+ /*
* We need to update the in-core inode size here so that we don't end up
* with the on-disk inode size being outside the in-core inode size. We
* have no other method of updating EOF for AIO, so always do it here
* here can result in EOF moving backwards and Bad Things Happen when
* that occurs.
*/
- spin_lock(&XFS_I(inode)->i_flags_lock);
+ spin_lock(&ip->i_flags_lock);
if (offset + size > i_size_read(inode))
i_size_write(inode, offset + size);
- spin_unlock(&XFS_I(inode)->i_flags_lock);
+ spin_unlock(&ip->i_flags_lock);
- /*
- * If we are doing an append IO that needs to update the EOF on disk,
- * do the transaction reserve now so we can use common end io
- * processing. Stashing the error (if there is one) in the ioend will
- * result in the ioend processing passing on the error if it is
- * possible as we can't return it from here.
- */
- if (ioend->io_type == XFS_IO_OVERWRITE)
- ioend->io_error = xfs_setfilesize_trans_alloc(ioend);
+ if (flags & XFS_DIO_FLAG_UNWRITTEN) {
+ trace_xfs_end_io_direct_write_unwritten(ip, offset, size);
-out_end_io:
- xfs_end_io(&ioend->io_work);
- return;
-}
+ error = xfs_iomap_write_unwritten(ip, offset, size);
+ } else if (flags & XFS_DIO_FLAG_APPEND) {
+ struct xfs_trans *tp;
-/*
- * Complete a direct I/O write request.
- *
- * The ioend structure is passed from __xfs_get_blocks() to tell us what to do.
- * If no ioend exists (i.e. @private == NULL) then the write IO is an overwrite
- * wholly within the EOF and so there is nothing for us to do. Note that in this
- * case the completion can be called in interrupt context, whereas if we have an
- * ioend we will always be called in task context (i.e. from a workqueue).
- */
-STATIC void
-xfs_end_io_direct_write(
- struct kiocb *iocb,
- loff_t offset,
- ssize_t size,
- void *private)
-{
- struct inode *inode = file_inode(iocb->ki_filp);
- struct xfs_ioend *ioend = private;
+ trace_xfs_end_io_direct_write_append(ip, offset, size);
- trace_xfs_gbmap_direct_endio(XFS_I(inode), offset, size,
- ioend ? ioend->io_type : 0, NULL);
-
- if (!ioend) {
- ASSERT(offset + size <= i_size_read(inode));
- return;
+ tp = xfs_trans_alloc(mp, XFS_TRANS_FSYNC_TS);
+ error = xfs_trans_reserve(tp, &M_RES(mp)->tr_fsyncts, 0, 0);
+ if (error) {
+ xfs_trans_cancel(tp);
+ return error;
+ }
+ error = xfs_setfilesize(ip, tp, offset, size);
}
- __xfs_end_io_direct_write(inode, ioend, offset, size);
+ return error;
}
-static inline ssize_t
-xfs_vm_do_dio(
- struct inode *inode,
+STATIC ssize_t
+xfs_vm_direct_IO(
struct kiocb *iocb,
struct iov_iter *iter,
- loff_t offset,
- void (*endio)(struct kiocb *iocb,
- loff_t offset,
- ssize_t size,
- void *private),
- int flags)
+ loff_t offset)
{
+ struct inode *inode = iocb->ki_filp->f_mapping->host;
+ dio_iodone_t *endio = NULL;
+ int flags = 0;
struct block_device *bdev;
- if (IS_DAX(inode))
+ if (iov_iter_rw(iter) == WRITE) {
+ endio = xfs_end_io_direct_write;
+ flags = DIO_ASYNC_EXTEND;
+ }
+
+ if (IS_DAX(inode)) {
return dax_do_io(iocb, inode, iter, offset,
xfs_get_blocks_direct, endio, 0);
+ }
bdev = xfs_find_bdev_for_inode(inode);
return __blockdev_direct_IO(iocb, inode, bdev, iter, offset,
- xfs_get_blocks_direct, endio, NULL, flags);
-}
-
-STATIC ssize_t
-xfs_vm_direct_IO(
- struct kiocb *iocb,
- struct iov_iter *iter,
- loff_t offset)
-{
- struct inode *inode = iocb->ki_filp->f_mapping->host;
-
- if (iov_iter_rw(iter) == WRITE)
- return xfs_vm_do_dio(inode, iocb, iter, offset,
- xfs_end_io_direct_write, DIO_ASYNC_EXTEND);
- return xfs_vm_do_dio(inode, iocb, iter, offset, NULL, 0);
+ xfs_get_blocks_direct, endio, NULL, flags);
}
/*
if (block_start >= to)
break;
- if (!buffer_delay(bh))
+ /*
+ * 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;
- xfs_vm_kill_delalloc_range(inode, block_offset,
- block_offset + bh->b_size);
+ 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
clear_buffer_mapped(bh);
clear_buffer_new(bh);
clear_buffer_dirty(bh);
+ clear_buffer_unwritten(bh);
}
}
projects / mirror_ubuntu-bionic-kernel.git / blobdiff