Merge tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

Pull ext4 update from Ted Ts'o:
 "Lots of bug fixes, cleanups and optimizations.  In the bug fixes
  category, of note is a fix for on-line resizing file systems where the
  block size is smaller than the page size (i.e., file systems 1k blocks
  on x86, or more interestingly file systems with 4k blocks on Power or
  ia64 systems.)

  In the cleanup category, the ext4's punch hole implementation was
  significantly improved by Lukas Czerner, and now supports bigalloc
  file systems.  In addition, Jan Kara significantly cleaned up the
  write submission code path.  We also improved error checking and added
  a few sanity checks.

  In the optimizations category, two major optimizations deserve
  mention.  The first is that ext4_writepages() is now used for
  nodelalloc and ext3 compatibility mode.  This allows writes to be
  submitted much more efficiently as a single bio request, instead of
  being sent as individual 4k writes into the block layer (which then
  relied on the elevator code to coalesce the requests in the block
  queue).  Secondly, the extent cache shrink mechanism, which was
  introduce in 3.9, no longer has a scalability bottleneck caused by the
  i_es_lru spinlock.  Other optimizations include some changes to reduce
  CPU usage and to avoid issuing empty commits unnecessarily."

* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (86 commits)
  ext4: optimize starting extent in ext4_ext_rm_leaf()
  jbd2: invalidate handle if jbd2_journal_restart() fails
  ext4: translate flag bits to strings in tracepoints
  ext4: fix up error handling for mpage_map_and_submit_extent()
  jbd2: fix theoretical race in jbd2__journal_restart
  ext4: only zero partial blocks in ext4_zero_partial_blocks()
  ext4: check error return from ext4_write_inline_data_end()
  ext4: delete unnecessary C statements
  ext3,ext4: don't mess with dir_file->f_pos in htree_dirblock_to_tree()
  jbd2: move superblock checksum calculation to jbd2_write_superblock()
  ext4: pass inode pointer instead of file pointer to punch hole
  ext4: improve free space calculation for inline_data
  ext4: reduce object size when !CONFIG_PRINTK
  ext4: improve extent cache shrink mechanism to avoid to burn CPU time
  ext4: implement error handling of ext4_mb_new_preallocation()
  ext4: fix corruption when online resizing a fs with 1K block size
  ext4: delete unused variables
  ext4: return FIEMAP_EXTENT_UNKNOWN for delalloc extents
  jbd2: remove debug dependency on debug_fs and update Kconfig help text
  jbd2: use a single printk for jbd_debug()
  ...

1 files changed, 183 insertions, 142 deletions

diff --git a/fs/ext4/page-io.c b/fs/ext4/page-io.c
index 4acf1f78881..48786cdb5e6 100644
--- a/fs/ext4/page-io.c
+++ b/fs/ext4/page-io.c
@@ -46,46 +46,121 @@ void ext4_exit_pageio(void)
 }
 
 /*
- * This function is called by ext4_evict_inode() to make sure there is
- * no more pending I/O completion work left to do.
+ * Print an buffer I/O error compatible with the fs/buffer.c.  This
+ * provides compatibility with dmesg scrapers that look for a specific
+ * buffer I/O error message.  We really need a unified error reporting
+ * structure to userspace ala Digital Unix's uerf system, but it's
+ * probably not going to happen in my lifetime, due to LKML politics...
  */
-void ext4_ioend_shutdown(struct inode *inode)
+static void buffer_io_error(struct buffer_head *bh)
 {
-	wait_queue_head_t *wq = ext4_ioend_wq(inode);
+	char b[BDEVNAME_SIZE];
+	printk(KERN_ERR "Buffer I/O error on device %s, logical block %llu\n",
+			bdevname(bh->b_bdev, b),
+			(unsigned long long)bh->b_blocknr);
+}
 
-	wait_event(*wq, (atomic_read(&EXT4_I(inode)->i_ioend_count) == 0));
-	/*
-	 * We need to make sure the work structure is finished being
-	 * used before we let the inode get destroyed.
-	 */
-	if (work_pending(&EXT4_I(inode)->i_unwritten_work))
-		cancel_work_sync(&EXT4_I(inode)->i_unwritten_work);
+static void ext4_finish_bio(struct bio *bio)
+{
+	int i;
+	int error = !test_bit(BIO_UPTODATE, &bio->bi_flags);
+
+	for (i = 0; i < bio->bi_vcnt; i++) {
+		struct bio_vec *bvec = &bio->bi_io_vec[i];
+		struct page *page = bvec->bv_page;
+		struct buffer_head *bh, *head;
+		unsigned bio_start = bvec->bv_offset;
+		unsigned bio_end = bio_start + bvec->bv_len;
+		unsigned under_io = 0;
+		unsigned long flags;
+
+		if (!page)
+			continue;
+
+		if (error) {
+			SetPageError(page);
+			set_bit(AS_EIO, &page->mapping->flags);
+		}
+		bh = head = page_buffers(page);
+		/*
+		 * We check all buffers in the page under BH_Uptodate_Lock
+		 * to avoid races with other end io clearing async_write flags
+		 */
+		local_irq_save(flags);
+		bit_spin_lock(BH_Uptodate_Lock, &head->b_state);
+		do {
+			if (bh_offset(bh) < bio_start ||
+			    bh_offset(bh) + bh->b_size > bio_end) {
+				if (buffer_async_write(bh))
+					under_io++;
+				continue;
+			}
+			clear_buffer_async_write(bh);
+			if (error)
+				buffer_io_error(bh);
+		} while ((bh = bh->b_this_page) != head);
+		bit_spin_unlock(BH_Uptodate_Lock, &head->b_state);
+		local_irq_restore(flags);
+		if (!under_io)
+			end_page_writeback(page);
+	}
 }
 
-void ext4_free_io_end(ext4_io_end_t *io)
+static void ext4_release_io_end(ext4_io_end_t *io_end)
 {
-	BUG_ON(!io);
-	BUG_ON(!list_empty(&io->list));
-	BUG_ON(io->flag & EXT4_IO_END_UNWRITTEN);
+	struct bio *bio, *next_bio;
+
+	BUG_ON(!list_empty(&io_end->list));
+	BUG_ON(io_end->flag & EXT4_IO_END_UNWRITTEN);
+	WARN_ON(io_end->handle);
 
-	if (atomic_dec_and_test(&EXT4_I(io->inode)->i_ioend_count))
-		wake_up_all(ext4_ioend_wq(io->inode));
-	kmem_cache_free(io_end_cachep, io);
+	if (atomic_dec_and_test(&EXT4_I(io_end->inode)->i_ioend_count))
+		wake_up_all(ext4_ioend_wq(io_end->inode));
+
+	for (bio = io_end->bio; bio; bio = next_bio) {
+		next_bio = bio->bi_private;
+		ext4_finish_bio(bio);
+		bio_put(bio);
+	}
+	if (io_end->flag & EXT4_IO_END_DIRECT)
+		inode_dio_done(io_end->inode);
+	if (io_end->iocb)
+		aio_complete(io_end->iocb, io_end->result, 0);
+	kmem_cache_free(io_end_cachep, io_end);
 }
 
-/* check a range of space and convert unwritten extents to written. */
+static void ext4_clear_io_unwritten_flag(ext4_io_end_t *io_end)
+{
+	struct inode *inode = io_end->inode;
+
+	io_end->flag &= ~EXT4_IO_END_UNWRITTEN;
+	/* Wake up anyone waiting on unwritten extent conversion */
+	if (atomic_dec_and_test(&EXT4_I(inode)->i_unwritten))
+		wake_up_all(ext4_ioend_wq(inode));
+}
+
+/*
+ * Check a range of space and convert unwritten extents to written. Note that
+ * we are protected from truncate touching same part of extent tree by the
+ * fact that truncate code waits for all DIO to finish (thus exclusion from
+ * direct IO is achieved) and also waits for PageWriteback bits. Thus we
+ * cannot get to ext4_ext_truncate() before all IOs overlapping that range are
+ * completed (happens from ext4_free_ioend()).
+ */
 static int ext4_end_io(ext4_io_end_t *io)
 {
 	struct inode *inode = io->inode;
 	loff_t offset = io->offset;
 	ssize_t size = io->size;
+	handle_t *handle = io->handle;
 	int ret = 0;
 
 	ext4_debug("ext4_end_io_nolock: io 0x%p from inode %lu,list->next 0x%p,"
 		   "list->prev 0x%p\n",
 		   io, inode->i_ino, io->list.next, io->list.prev);
 
-	ret = ext4_convert_unwritten_extents(inode, offset, size);
+	io->handle = NULL;	/* Following call will use up the handle */
+	ret = ext4_convert_unwritten_extents(handle, inode, offset, size);
 	if (ret < 0) {
 		ext4_msg(inode->i_sb, KERN_EMERG,
 			 "failed to convert unwritten extents to written "
@@ -93,30 +168,22 @@ static int ext4_end_io(ext4_io_end_t *io)
 			 "(inode %lu, offset %llu, size %zd, error %d)",
 			 inode->i_ino, offset, size, ret);
 	}
-	/* Wake up anyone waiting on unwritten extent conversion */
-	if (atomic_dec_and_test(&EXT4_I(inode)->i_unwritten))
-		wake_up_all(ext4_ioend_wq(inode));
-	if (io->flag & EXT4_IO_END_DIRECT)
-		inode_dio_done(inode);
-	if (io->iocb)
-		aio_complete(io->iocb, io->result, 0);
+	ext4_clear_io_unwritten_flag(io);
+	ext4_release_io_end(io);
 	return ret;
 }
 
-static void dump_completed_IO(struct inode *inode)
+static void dump_completed_IO(struct inode *inode, struct list_head *head)
 {
 #ifdef	EXT4FS_DEBUG
 	struct list_head *cur, *before, *after;
 	ext4_io_end_t *io, *io0, *io1;
 
-	if (list_empty(&EXT4_I(inode)->i_completed_io_list)) {
-		ext4_debug("inode %lu completed_io list is empty\n",
-			   inode->i_ino);
+	if (list_empty(head))
 		return;
-	}
 
-	ext4_debug("Dump inode %lu completed_io list\n", inode->i_ino);
-	list_for_each_entry(io, &EXT4_I(inode)->i_completed_io_list, list) {
+	ext4_debug("Dump inode %lu completed io list\n", inode->i_ino);
+	list_for_each_entry(io, head, list) {
 		cur = &io->list;
 		before = cur->prev;
 		io0 = container_of(before, ext4_io_end_t, list);
@@ -130,23 +197,30 @@ static void dump_completed_IO(struct inode *inode)
 }
 
 /* Add the io_end to per-inode completed end_io list. */
-void ext4_add_complete_io(ext4_io_end_t *io_end)
+static void ext4_add_complete_io(ext4_io_end_t *io_end)
 {
 	struct ext4_inode_info *ei = EXT4_I(io_end->inode);
 	struct workqueue_struct *wq;
 	unsigned long flags;
 
 	BUG_ON(!(io_end->flag & EXT4_IO_END_UNWRITTEN));
-	wq = EXT4_SB(io_end->inode->i_sb)->dio_unwritten_wq;
-
 	spin_lock_irqsave(&ei->i_completed_io_lock, flags);
-	if (list_empty(&ei->i_completed_io_list))
-		queue_work(wq, &ei->i_unwritten_work);
-	list_add_tail(&io_end->list, &ei->i_completed_io_list);
+	if (io_end->handle) {
+		wq = EXT4_SB(io_end->inode->i_sb)->rsv_conversion_wq;
+		if (list_empty(&ei->i_rsv_conversion_list))
+			queue_work(wq, &ei->i_rsv_conversion_work);
+		list_add_tail(&io_end->list, &ei->i_rsv_conversion_list);
+	} else {
+		wq = EXT4_SB(io_end->inode->i_sb)->unrsv_conversion_wq;
+		if (list_empty(&ei->i_unrsv_conversion_list))
+			queue_work(wq, &ei->i_unrsv_conversion_work);
+		list_add_tail(&io_end->list, &ei->i_unrsv_conversion_list);
+	}
 	spin_unlock_irqrestore(&ei->i_completed_io_lock, flags);
 }
 
-static int ext4_do_flush_completed_IO(struct inode *inode)
+static int ext4_do_flush_completed_IO(struct inode *inode,
+				      struct list_head *head)
 {
 	ext4_io_end_t *io;
 	struct list_head unwritten;
@@ -155,8 +229,8 @@ static int ext4_do_flush_completed_IO(struct inode *inode)
 	int err, ret = 0;
 
 	spin_lock_irqsave(&ei->i_completed_io_lock, flags);
-	dump_completed_IO(inode);
-	list_replace_init(&ei->i_completed_io_list, &unwritten);
+	dump_completed_IO(inode, head);
+	list_replace_init(head, &unwritten);
 	spin_unlock_irqrestore(&ei->i_completed_io_lock, flags);
 
 	while (!list_empty(&unwritten)) {
@@ -167,30 +241,25 @@ static int ext4_do_flush_completed_IO(struct inode *inode)
 		err = ext4_end_io(io);
 		if (unlikely(!ret && err))
 			ret = err;
-		io->flag &= ~EXT4_IO_END_UNWRITTEN;
-		ext4_free_io_end(io);
 	}
 	return ret;
 }
 
 /*
- * work on completed aio dio IO, to convert unwritten extents to extents
+ * work on completed IO, to convert unwritten extents to extents
  */
-void ext4_end_io_work(struct work_struct *work)
+void ext4_end_io_rsv_work(struct work_struct *work)
 {
 	struct ext4_inode_info *ei = container_of(work, struct ext4_inode_info,
-						  i_unwritten_work);
-	ext4_do_flush_completed_IO(&ei->vfs_inode);
+						  i_rsv_conversion_work);
+	ext4_do_flush_completed_IO(&ei->vfs_inode, &ei->i_rsv_conversion_list);
 }
 
-int ext4_flush_unwritten_io(struct inode *inode)
+void ext4_end_io_unrsv_work(struct work_struct *work)
 {
-	int ret;
-	WARN_ON_ONCE(!mutex_is_locked(&inode->i_mutex) &&
-		     !(inode->i_state & I_FREEING));
-	ret = ext4_do_flush_completed_IO(inode);
-	ext4_unwritten_wait(inode);
-	return ret;
+	struct ext4_inode_info *ei = container_of(work, struct ext4_inode_info,
+						  i_unrsv_conversion_work);
+	ext4_do_flush_completed_IO(&ei->vfs_inode, &ei->i_unrsv_conversion_list);
 }
 
 ext4_io_end_t *ext4_init_io_end(struct inode *inode, gfp_t flags)
@@ -200,83 +269,70 @@ ext4_io_end_t *ext4_init_io_end(struct inode *inode, gfp_t flags)
 		atomic_inc(&EXT4_I(inode)->i_ioend_count);
 		io->inode = inode;
 		INIT_LIST_HEAD(&io->list);
+		atomic_set(&io->count, 1);
 	}
 	return io;
 }
 
-/*
- * Print an buffer I/O error compatible with the fs/buffer.c.  This
- * provides compatibility with dmesg scrapers that look for a specific
- * buffer I/O error message.  We really need a unified error reporting
- * structure to userspace ala Digital Unix's uerf system, but it's
- * probably not going to happen in my lifetime, due to LKML politics...
- */
-static void buffer_io_error(struct buffer_head *bh)
+void ext4_put_io_end_defer(ext4_io_end_t *io_end)
 {
-	char b[BDEVNAME_SIZE];
-	printk(KERN_ERR "Buffer I/O error on device %s, logical block %llu\n",
-			bdevname(bh->b_bdev, b),
-			(unsigned long long)bh->b_blocknr);
+	if (atomic_dec_and_test(&io_end->count)) {
+		if (!(io_end->flag & EXT4_IO_END_UNWRITTEN) || !io_end->size) {
+			ext4_release_io_end(io_end);
+			return;
+		}
+		ext4_add_complete_io(io_end);
+	}
+}
+
+int ext4_put_io_end(ext4_io_end_t *io_end)
+{
+	int err = 0;
+
+	if (atomic_dec_and_test(&io_end->count)) {
+		if (io_end->flag & EXT4_IO_END_UNWRITTEN) {
+			err = ext4_convert_unwritten_extents(io_end->handle,
+						io_end->inode, io_end->offset,
+						io_end->size);
+			io_end->handle = NULL;
+			ext4_clear_io_unwritten_flag(io_end);
+		}
+		ext4_release_io_end(io_end);
+	}
+	return err;
+}
+
+ext4_io_end_t *ext4_get_io_end(ext4_io_end_t *io_end)
+{
+	atomic_inc(&io_end->count);
+	return io_end;
 }
 
 static void ext4_end_bio(struct bio *bio, int error)
 {
 	ext4_io_end_t *io_end = bio->bi_private;
-	struct inode *inode;
-	int i;
-	int blocksize;
 	sector_t bi_sector = bio->bi_sector;
 
 	BUG_ON(!io_end);
-	inode = io_end->inode;
-	blocksize = 1 << inode->i_blkbits;
-	bio->bi_private = NULL;
 	bio->bi_end_io = NULL;
 	if (test_bit(BIO_UPTODATE, &bio->bi_flags))
 		error = 0;
-	for (i = 0; i < bio->bi_vcnt; i++) {
-		struct bio_vec *bvec = &bio->bi_io_vec[i];
-		struct page *page = bvec->bv_page;
-		struct buffer_head *bh, *head;
-		unsigned bio_start = bvec->bv_offset;
-		unsigned bio_end = bio_start + bvec->bv_len;
-		unsigned under_io = 0;
-		unsigned long flags;
 
-		if (!page)
-			continue;
-
-		if (error) {
-			SetPageError(page);
-			set_bit(AS_EIO, &page->mapping->flags);
-		}
-		bh = head = page_buffers(page);
+	if (io_end->flag & EXT4_IO_END_UNWRITTEN) {
 		/*
-		 * We check all buffers in the page under BH_Uptodate_Lock
-		 * to avoid races with other end io clearing async_write flags
+		 * Link bio into list hanging from io_end. We have to do it
+		 * atomically as bio completions can be racing against each
+		 * other.
 		 */
-		local_irq_save(flags);
-		bit_spin_lock(BH_Uptodate_Lock, &head->b_state);
-		do {
-			if (bh_offset(bh) < bio_start ||
-			    bh_offset(bh) + blocksize > bio_end) {
-				if (buffer_async_write(bh))
-					under_io++;
-				continue;
-			}
-			clear_buffer_async_write(bh);
-			if (error)
-				buffer_io_error(bh);
-		} while ((bh = bh->b_this_page) != head);
-		bit_spin_unlock(BH_Uptodate_Lock, &head->b_state);
-		local_irq_restore(flags);
-		if (!under_io)
-			end_page_writeback(page);
+		bio->bi_private = xchg(&io_end->bio, bio);
+	} else {
+		ext4_finish_bio(bio);
+		bio_put(bio);
 	}
-	bio_put(bio);
 
 	if (error) {
-		io_end->flag |= EXT4_IO_END_ERROR;
+		struct inode *inode = io_end->inode;
+
 		ext4_warning(inode->i_sb, "I/O error writing to inode %lu "
 			     "(offset %llu size %ld starting block %llu)",
 			     inode->i_ino,
@@ -285,13 +341,7 @@ static void ext4_end_bio(struct bio *bio, int error)
 			     (unsigned long long)
 			     bi_sector >> (inode->i_blkbits - 9));
 	}
-
-	if (!(io_end->flag & EXT4_IO_END_UNWRITTEN)) {
-		ext4_free_io_end(io_end);
-		return;
-	}
-
-	ext4_add_complete_io(io_end);
+	ext4_put_io_end_defer(io_end);
 }
 
 void ext4_io_submit(struct ext4_io_submit *io)
@@ -305,43 +355,38 @@ void ext4_io_submit(struct ext4_io_submit *io)
 		bio_put(io->io_bio);
 	}
 	io->io_bio = NULL;
-	io->io_op = 0;
+}
+
+void ext4_io_submit_init(struct ext4_io_submit *io,
+			 struct writeback_control *wbc)
+{
+	io->io_op = (wbc->sync_mode == WB_SYNC_ALL ?  WRITE_SYNC : WRITE);
+	io->io_bio = NULL;
 	io->io_end = NULL;
 }
 
-static int io_submit_init(struct ext4_io_submit *io,
-			  struct inode *inode,
-			  struct writeback_control *wbc,
-			  struct buffer_head *bh)
+static int io_submit_init_bio(struct ext4_io_submit *io,
+			      struct buffer_head *bh)
 {
-	ext4_io_end_t *io_end;
-	struct page *page = bh->b_page;
 	int nvecs = bio_get_nr_vecs(bh->b_bdev);
 	struct bio *bio;
 
-	io_end = ext4_init_io_end(inode, GFP_NOFS);
-	if (!io_end)
-		return -ENOMEM;
 	bio = bio_alloc(GFP_NOIO, min(nvecs, BIO_MAX_PAGES));
+	if (!bio)
+		return -ENOMEM;
 	bio->bi_sector = bh->b_blocknr * (bh->b_size >> 9);
 	bio->bi_bdev = bh->b_bdev;
-	bio->bi_private = io->io_end = io_end;
 	bio->bi_end_io = ext4_end_bio;
-
-	io_end->offset = (page->index << PAGE_CACHE_SHIFT) + bh_offset(bh);
-
+	bio->bi_private = ext4_get_io_end(io->io_end);
 	io->io_bio = bio;
-	io->io_op = (wbc->sync_mode == WB_SYNC_ALL ?  WRITE_SYNC : WRITE);
 	io->io_next_block = bh->b_blocknr;
 	return 0;
 }
 
 static int io_submit_add_bh(struct ext4_io_submit *io,
 			    struct inode *inode,
-			    struct writeback_control *wbc,
 			    struct buffer_head *bh)
 {
-	ext4_io_end_t *io_end;
 	int ret;
 
 	if (io->io_bio && bh->b_blocknr != io->io_next_block) {
@@ -349,18 +394,14 @@ submit_and_retry:
 		ext4_io_submit(io);
 	}
 	if (io->io_bio == NULL) {
-		ret = io_submit_init(io, inode, wbc, bh);
+		ret = io_submit_init_bio(io, bh);
 		if (ret)
 			return ret;
 	}
-	io_end = io->io_end;
-	if (test_clear_buffer_uninit(bh))
-		ext4_set_io_unwritten_flag(inode, io_end);
-	io->io_end->size += bh->b_size;
-	io->io_next_block++;
 	ret = bio_add_page(io->io_bio, bh->b_page, bh->b_size, bh_offset(bh));
 	if (ret != bh->b_size)
 		goto submit_and_retry;
+	io->io_next_block++;
 	return 0;
 }
 
@@ -432,7 +473,7 @@ int ext4_bio_write_page(struct ext4_io_submit *io,
 	do {
 		if (!buffer_async_write(bh))
 			continue;
-		ret = io_submit_add_bh(io, inode, wbc, bh);
+		ret = io_submit_add_bh(io, inode, bh);
 		if (ret) {
 			/*
 			 * We only get here on ENOMEM.  Not much else