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Commit 78e62c02 authored by Nikolay Borisov's avatar Nikolay Borisov Committed by David Sterba
Browse files

btrfs: Remove extent_io_ops::readpage_io_failed_hook 



For data inodes this hook does nothing but to return -EAGAIN which is
used to signal to the endio routines that this bio belongs to a data
inode. If this is the case the actual retrying is handled by
bio_readpage_error. Alternatively, if this bio belongs to the btree
inode then btree_io_failed_hook just does some cleanup and doesn't retry
anything.

This patch simplifies the code flow by eliminating
readpage_io_failed_hook and instead open-coding btree_io_failed_hook in
end_bio_extent_readpage. Also eliminate some needless checks since IO is
always performed on either data inode or btree inode, both of which are
guaranteed to have their extent_io_tree::ops set.

Signed-off-by: default avatarNikolay Borisov <nborisov@suse.com>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 7b41ba71

fs/btrfs/disk-io.c

+0 −16
Original line number Diff line number Diff line
@@ -673,19 +673,6 @@ static int btree_readpage_end_io_hook(struct btrfs_io_bio *io_bio, 
	return ret;

}



static int btree_io_failed_hook(struct page *page, int failed_mirror)

{

	struct extent_buffer *eb;



	eb = (struct extent_buffer *)page->private;

	set_bit(EXTENT_BUFFER_READ_ERR, &eb->bflags);

	eb->read_mirror = failed_mirror;

	atomic_dec(&eb->io_pages);

	if (test_and_clear_bit(EXTENT_BUFFER_READAHEAD, &eb->bflags))

		btree_readahead_hook(eb, -EIO);

	return -EIO;	/* we fixed nothing */

}



static void end_workqueue_bio(struct bio *bio)

{

	struct btrfs_end_io_wq *end_io_wq = bio->bi_private;
@@ -4560,7 +4547,4 @@ static const struct extent_io_ops btree_extent_io_ops = { 
	/* mandatory callbacks */

	.submit_bio_hook = btree_submit_bio_hook,

	.readpage_end_io_hook = btree_readpage_end_io_hook,

	.readpage_io_failed_hook = btree_io_failed_hook,



	/* optional callbacks */

};

fs/btrfs/extent_io.c

+35 −36
Original line number Diff line number Diff line
@@ -2333,13 +2333,11 @@ struct bio *btrfs_create_repair_bio(struct inode *inode, struct bio *failed_bio, 
}



/*

 * this is a generic handler for readpage errors (default

 * readpage_io_failed_hook). if other copies exist, read those and write back

 * good data to the failed position. does not investigate in remapping the

 * failed extent elsewhere, hoping the device will be smart enough to do this as

 * needed

 * This is a generic handler for readpage errors. If other copies exist, read

 * those and write back good data to the failed position. Does not investigate

 * in remapping the failed extent elsewhere, hoping the device will be smart

 * enough to do this as needed

 */



static int bio_readpage_error(struct bio *failed_bio, u64 phy_offset,

			      struct page *page, u64 start, u64 end,

			      int failed_mirror)
@@ -2501,6 +2499,8 @@ static void end_bio_extent_readpage(struct bio *bio) 
		struct page *page = bvec->bv_page;

		struct inode *inode = page->mapping->host;

		struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);

		bool data_inode = btrfs_ino(BTRFS_I(inode))

			!= BTRFS_BTREE_INODE_OBJECTID;



		btrfs_debug(fs_info,

			"end_bio_extent_readpage: bi_sector=%llu, err=%d, mirror=%u",
@@ -2530,7 +2530,7 @@ static void end_bio_extent_readpage(struct bio *bio) 
		len = bvec->bv_len;



		mirror = io_bio->mirror_num;

		if (likely(uptodate && tree->ops)) {

		if (likely(uptodate)) {

			ret = tree->ops->readpage_end_io_hook(io_bio, offset,

							      page, start, end,

							      mirror);
@@ -2546,38 +2546,37 @@ static void end_bio_extent_readpage(struct bio *bio) 
		if (likely(uptodate))

			goto readpage_ok;



		if (tree->ops) {

			ret = tree->ops->readpage_io_failed_hook(page, mirror);

			if (ret == -EAGAIN) {

		if (data_inode) {



			/*

				 * Data inode's readpage_io_failed_hook() always

				 * returns -EAGAIN.

				 *

				 * The generic bio_readpage_error handles errors

				 * the following way: If possible, new read

				 * requests are created and submitted and will

				 * end up in end_bio_extent_readpage as well (if

				 * we're lucky, not in the !uptodate case). In

				 * that case it returns 0 and we just go on with

				 * the next page in our bio. If it can't handle

				 * the error it will return -EIO and we remain

				 * responsible for that page.

				 */

				ret = bio_readpage_error(bio, offset, page,

							 start, end, mirror);

			 * The generic bio_readpage_error handles errors the

			 * following way: If possible, new read requests are

			 * created and submitted and will end up in

			 * end_bio_extent_readpage as well (if we're lucky,

			 * not in the !uptodate case). In that case it returns

			 * 0 and we just go on with the next page in our bio.

			 * If it can't handle the error it will return -EIO and

			 * we remain responsible for that page.

			 */

			ret = bio_readpage_error(bio, offset, page, start, end,

						 mirror);

			if (ret == 0) {

				uptodate = !bio->bi_status;

				offset += len;

				continue;

			}

			}

		} else {

			struct extent_buffer *eb;



			/*

			 * metadata's readpage_io_failed_hook() always returns

			 * -EIO and fixes nothing.  -EIO is also returned if

			 * data inode error could not be fixed.

			 */

			ASSERT(ret == -EIO);

			eb = (struct extent_buffer *)page->private;

			set_bit(EXTENT_BUFFER_READ_ERR, &eb->bflags);

			eb->read_mirror = mirror;

			atomic_dec(&eb->io_pages);

			if (test_and_clear_bit(EXTENT_BUFFER_READAHEAD,

					       &eb->bflags))

				btree_readahead_hook(eb, -EIO);



			ret = -EIO;

		}

readpage_ok:

		if (likely(uptodate)) {

fs/btrfs/extent_io.h

+0 −1
Original line number Diff line number Diff line
@@ -101,7 +101,6 @@ struct extent_io_ops { 
	int (*readpage_end_io_hook)(struct btrfs_io_bio *io_bio, u64 phy_offset,

				    struct page *page, u64 start, u64 end,

				    int mirror);

	int (*readpage_io_failed_hook)(struct page *page, int failed_mirror);

};



struct extent_io_tree {

fs/btrfs/inode.c

+0 −7
Original line number Diff line number Diff line
@@ -10409,12 +10409,6 @@ static int btrfs_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode) 
	return ret;

}



__attribute__((const))

static int btrfs_readpage_io_failed_hook(struct page *page, int failed_mirror)

{

	return -EAGAIN;

}



void btrfs_set_range_writeback(struct extent_io_tree *tree, u64 start, u64 end)

{

	struct inode *inode = tree->private_data;
@@ -10810,7 +10804,6 @@ static const struct extent_io_ops btrfs_extent_io_ops = { 
	/* mandatory callbacks */

	.submit_bio_hook = btrfs_submit_bio_hook,

	.readpage_end_io_hook = btrfs_readpage_end_io_hook,

	.readpage_io_failed_hook = btrfs_readpage_io_failed_hook,

};



/*