From c8cc88163f40df39e50cda63ac361631864b453e Mon Sep 17 00:00:00 2001 From: Ritesh Harjani Date: Wed, 16 Oct 2019 13:07:10 +0530 Subject: ext4: Add support for blocksize < pagesize in dioread_nolock This patch adds the support for blocksize < pagesize for dioread_nolock feature. Since in case of blocksize < pagesize, we can have multiple small buffers of page as unwritten extents, we need to maintain a vector of these unwritten extents which needs the conversion after the IO is complete. Thus, we maintain a list of tuple pair (io_end_vec) for this & traverse this list to do the unwritten to written conversion. Signed-off-by: Ritesh Harjani Link: https://lore.kernel.org/r/20191016073711.4141-5-riteshh@linux.ibm.com Signed-off-by: Theodore Ts'o --- fs/ext4/page-io.c | 52 ++++++++++++++++++++++++++++++++++++++++++++-------- 1 file changed, 44 insertions(+), 8 deletions(-) (limited to 'fs/ext4/page-io.c') diff --git a/fs/ext4/page-io.c b/fs/ext4/page-io.c index 3ccf54a380b2..893913d1c2fe 100644 --- a/fs/ext4/page-io.c +++ b/fs/ext4/page-io.c @@ -31,18 +31,56 @@ #include "acl.h" static struct kmem_cache *io_end_cachep; +static struct kmem_cache *io_end_vec_cachep; int __init ext4_init_pageio(void) { io_end_cachep = KMEM_CACHE(ext4_io_end, SLAB_RECLAIM_ACCOUNT); if (io_end_cachep == NULL) return -ENOMEM; + + io_end_vec_cachep = KMEM_CACHE(ext4_io_end_vec, 0); + if (io_end_vec_cachep == NULL) { + kmem_cache_destroy(io_end_cachep); + return -ENOMEM; + } return 0; } void ext4_exit_pageio(void) { kmem_cache_destroy(io_end_cachep); + kmem_cache_destroy(io_end_vec_cachep); +} + +struct ext4_io_end_vec *ext4_alloc_io_end_vec(ext4_io_end_t *io_end) +{ + struct ext4_io_end_vec *io_end_vec; + + io_end_vec = kmem_cache_zalloc(io_end_vec_cachep, GFP_NOFS); + if (!io_end_vec) + return ERR_PTR(-ENOMEM); + INIT_LIST_HEAD(&io_end_vec->list); + list_add_tail(&io_end_vec->list, &io_end->list_vec); + return io_end_vec; +} + +static void ext4_free_io_end_vec(ext4_io_end_t *io_end) +{ + struct ext4_io_end_vec *io_end_vec, *tmp; + + if (list_empty(&io_end->list_vec)) + return; + list_for_each_entry_safe(io_end_vec, tmp, &io_end->list_vec, list) { + list_del(&io_end_vec->list); + kmem_cache_free(io_end_vec_cachep, io_end_vec); + } +} + +struct ext4_io_end_vec *ext4_last_io_end_vec(ext4_io_end_t *io_end) +{ + BUG_ON(list_empty(&io_end->list_vec)); + return list_last_entry(&io_end->list_vec, struct ext4_io_end_vec, list); } /* @@ -125,6 +163,7 @@ static void ext4_release_io_end(ext4_io_end_t *io_end) ext4_finish_bio(bio); bio_put(bio); } + ext4_free_io_end_vec(io_end); kmem_cache_free(io_end_cachep, io_end); } @@ -139,8 +178,6 @@ static void ext4_release_io_end(ext4_io_end_t *io_end) static int ext4_end_io_end(ext4_io_end_t *io_end) { struct inode *inode = io_end->inode; - loff_t offset = io_end->offset; - ssize_t size = io_end->size; handle_t *handle = io_end->handle; int ret = 0; @@ -154,8 +191,7 @@ static int ext4_end_io_end(ext4_io_end_t *io_end) ext4_msg(inode->i_sb, KERN_EMERG, "failed to convert unwritten extents to written " "extents -- potential data loss! " - "(inode %lu, offset %llu, size %zd, error %d)", - inode->i_ino, offset, size, ret); + "(inode %lu, error %d)", inode->i_ino, ret); } ext4_clear_io_unwritten_flag(io_end); ext4_release_io_end(io_end); @@ -247,6 +283,7 @@ ext4_io_end_t *ext4_init_io_end(struct inode *inode, gfp_t flags) if (io_end) { io_end->inode = inode; INIT_LIST_HEAD(&io_end->list); + INIT_LIST_HEAD(&io_end->list_vec); atomic_set(&io_end->count, 1); } return io_end; @@ -255,7 +292,8 @@ ext4_io_end_t *ext4_init_io_end(struct inode *inode, gfp_t flags) void ext4_put_io_end_defer(ext4_io_end_t *io_end) { if (atomic_dec_and_test(&io_end->count)) { - if (!(io_end->flag & EXT4_IO_END_UNWRITTEN) || !io_end->size) { + if (!(io_end->flag & EXT4_IO_END_UNWRITTEN) || + list_empty(&io_end->list_vec)) { ext4_release_io_end(io_end); return; } @@ -307,10 +345,8 @@ static void ext4_end_bio(struct bio *bio) struct inode *inode = io_end->inode; ext4_warning(inode->i_sb, "I/O error %d writing to inode %lu " - "(offset %llu size %ld starting block %llu)", + "starting block %llu)", bio->bi_status, inode->i_ino, - (unsigned long long) io_end->offset, - (long) io_end->size, (unsigned long long) bi_sector >> (inode->i_blkbits - 9)); mapping_set_error(inode->i_mapping, -- cgit