1bd2d0210STheodore Ts'o /* 2bd2d0210STheodore Ts'o * linux/fs/ext4/page-io.c 3bd2d0210STheodore Ts'o * 4bd2d0210STheodore Ts'o * This contains the new page_io functions for ext4 5bd2d0210STheodore Ts'o * 6bd2d0210STheodore Ts'o * Written by Theodore Ts'o, 2010. 7bd2d0210STheodore Ts'o */ 8bd2d0210STheodore Ts'o 9bd2d0210STheodore Ts'o #include <linux/fs.h> 10bd2d0210STheodore Ts'o #include <linux/time.h> 11bd2d0210STheodore Ts'o #include <linux/highuid.h> 12bd2d0210STheodore Ts'o #include <linux/pagemap.h> 13bd2d0210STheodore Ts'o #include <linux/quotaops.h> 14bd2d0210STheodore Ts'o #include <linux/string.h> 15bd2d0210STheodore Ts'o #include <linux/buffer_head.h> 16bd2d0210STheodore Ts'o #include <linux/writeback.h> 17bd2d0210STheodore Ts'o #include <linux/pagevec.h> 18bd2d0210STheodore Ts'o #include <linux/mpage.h> 19bd2d0210STheodore Ts'o #include <linux/namei.h> 20bd2d0210STheodore Ts'o #include <linux/uio.h> 21bd2d0210STheodore Ts'o #include <linux/bio.h> 22bd2d0210STheodore Ts'o #include <linux/workqueue.h> 23bd2d0210STheodore Ts'o #include <linux/kernel.h> 24bd2d0210STheodore Ts'o #include <linux/slab.h> 251ae48a63SJan Kara #include <linux/mm.h> 26bd2d0210STheodore Ts'o 27bd2d0210STheodore Ts'o #include "ext4_jbd2.h" 28bd2d0210STheodore Ts'o #include "xattr.h" 29bd2d0210STheodore Ts'o #include "acl.h" 30bd2d0210STheodore Ts'o 310058f965SJan Kara static struct kmem_cache *io_end_cachep; 32bd2d0210STheodore Ts'o 335dabfc78STheodore Ts'o int __init ext4_init_pageio(void) 34bd2d0210STheodore Ts'o { 35bd2d0210STheodore Ts'o io_end_cachep = KMEM_CACHE(ext4_io_end, SLAB_RECLAIM_ACCOUNT); 360058f965SJan Kara if (io_end_cachep == NULL) 37bd2d0210STheodore Ts'o return -ENOMEM; 38bd2d0210STheodore Ts'o return 0; 39bd2d0210STheodore Ts'o } 40bd2d0210STheodore Ts'o 415dabfc78STheodore Ts'o void ext4_exit_pageio(void) 42bd2d0210STheodore Ts'o { 43bd2d0210STheodore Ts'o kmem_cache_destroy(io_end_cachep); 44bd2d0210STheodore Ts'o } 45bd2d0210STheodore Ts'o 461ada47d9STheodore Ts'o /* 47b0857d30SJan Kara * Print an buffer I/O error compatible with the fs/buffer.c. This 48b0857d30SJan Kara * provides compatibility with dmesg scrapers that look for a specific 49b0857d30SJan Kara * buffer I/O error message. We really need a unified error reporting 50b0857d30SJan Kara * structure to userspace ala Digital Unix's uerf system, but it's 51b0857d30SJan Kara * probably not going to happen in my lifetime, due to LKML politics... 52b0857d30SJan Kara */ 53b0857d30SJan Kara static void buffer_io_error(struct buffer_head *bh) 54b0857d30SJan Kara { 55a1c6f057SDmitry Monakhov printk_ratelimited(KERN_ERR "Buffer I/O error on device %pg, logical block %llu\n", 56a1c6f057SDmitry Monakhov bh->b_bdev, 57b0857d30SJan Kara (unsigned long long)bh->b_blocknr); 58b0857d30SJan Kara } 59b0857d30SJan Kara 60b0857d30SJan Kara static void ext4_finish_bio(struct bio *bio) 61b0857d30SJan Kara { 62b0857d30SJan Kara int i; 632c30c71bSKent Overstreet struct bio_vec *bvec; 64b0857d30SJan Kara 652c30c71bSKent Overstreet bio_for_each_segment_all(bvec, bio, i) { 66b0857d30SJan Kara struct page *page = bvec->bv_page; 672058f83aSMichael Halcrow #ifdef CONFIG_EXT4_FS_ENCRYPTION 682058f83aSMichael Halcrow struct page *data_page = NULL; 692058f83aSMichael Halcrow struct ext4_crypto_ctx *ctx = NULL; 702058f83aSMichael Halcrow #endif 71b0857d30SJan Kara struct buffer_head *bh, *head; 72b0857d30SJan Kara unsigned bio_start = bvec->bv_offset; 73b0857d30SJan Kara unsigned bio_end = bio_start + bvec->bv_len; 74b0857d30SJan Kara unsigned under_io = 0; 75b0857d30SJan Kara unsigned long flags; 76b0857d30SJan Kara 77b0857d30SJan Kara if (!page) 78b0857d30SJan Kara continue; 79b0857d30SJan Kara 802058f83aSMichael Halcrow #ifdef CONFIG_EXT4_FS_ENCRYPTION 812058f83aSMichael Halcrow if (!page->mapping) { 822058f83aSMichael Halcrow /* The bounce data pages are unmapped. */ 832058f83aSMichael Halcrow data_page = page; 842058f83aSMichael Halcrow ctx = (struct ext4_crypto_ctx *)page_private(data_page); 85614def70STheodore Ts'o page = ctx->w.control_page; 862058f83aSMichael Halcrow } 872058f83aSMichael Halcrow #endif 882058f83aSMichael Halcrow 894246a0b6SChristoph Hellwig if (bio->bi_error) { 90b0857d30SJan Kara SetPageError(page); 91b0857d30SJan Kara set_bit(AS_EIO, &page->mapping->flags); 92b0857d30SJan Kara } 93b0857d30SJan Kara bh = head = page_buffers(page); 94b0857d30SJan Kara /* 95b0857d30SJan Kara * We check all buffers in the page under BH_Uptodate_Lock 96b0857d30SJan Kara * to avoid races with other end io clearing async_write flags 97b0857d30SJan Kara */ 98b0857d30SJan Kara local_irq_save(flags); 99b0857d30SJan Kara bit_spin_lock(BH_Uptodate_Lock, &head->b_state); 100b0857d30SJan Kara do { 101b0857d30SJan Kara if (bh_offset(bh) < bio_start || 102b0857d30SJan Kara bh_offset(bh) + bh->b_size > bio_end) { 103b0857d30SJan Kara if (buffer_async_write(bh)) 104b0857d30SJan Kara under_io++; 105b0857d30SJan Kara continue; 106b0857d30SJan Kara } 107b0857d30SJan Kara clear_buffer_async_write(bh); 1084246a0b6SChristoph Hellwig if (bio->bi_error) 109b0857d30SJan Kara buffer_io_error(bh); 110b0857d30SJan Kara } while ((bh = bh->b_this_page) != head); 111b0857d30SJan Kara bit_spin_unlock(BH_Uptodate_Lock, &head->b_state); 112b0857d30SJan Kara local_irq_restore(flags); 1132058f83aSMichael Halcrow if (!under_io) { 1142058f83aSMichael Halcrow #ifdef CONFIG_EXT4_FS_ENCRYPTION 1152058f83aSMichael Halcrow if (ctx) 1162058f83aSMichael Halcrow ext4_restore_control_page(data_page); 1172058f83aSMichael Halcrow #endif 118b0857d30SJan Kara end_page_writeback(page); 119b0857d30SJan Kara } 120b0857d30SJan Kara } 1212058f83aSMichael Halcrow } 122b0857d30SJan Kara 12397a851edSJan Kara static void ext4_release_io_end(ext4_io_end_t *io_end) 124bd2d0210STheodore Ts'o { 125b0857d30SJan Kara struct bio *bio, *next_bio; 126b0857d30SJan Kara 12797a851edSJan Kara BUG_ON(!list_empty(&io_end->list)); 12897a851edSJan Kara BUG_ON(io_end->flag & EXT4_IO_END_UNWRITTEN); 1296b523df4SJan Kara WARN_ON(io_end->handle); 130bd2d0210STheodore Ts'o 131b0857d30SJan Kara for (bio = io_end->bio; bio; bio = next_bio) { 132b0857d30SJan Kara next_bio = bio->bi_private; 133b0857d30SJan Kara ext4_finish_bio(bio); 134b0857d30SJan Kara bio_put(bio); 135b0857d30SJan Kara } 13697a851edSJan Kara kmem_cache_free(io_end_cachep, io_end); 13797a851edSJan Kara } 13897a851edSJan Kara 139a115f749SJan Kara /* 140a115f749SJan Kara * Check a range of space and convert unwritten extents to written. Note that 141a115f749SJan Kara * we are protected from truncate touching same part of extent tree by the 142a115f749SJan Kara * fact that truncate code waits for all DIO to finish (thus exclusion from 143a115f749SJan Kara * direct IO is achieved) and also waits for PageWriteback bits. Thus we 144a115f749SJan Kara * cannot get to ext4_ext_truncate() before all IOs overlapping that range are 145a115f749SJan Kara * completed (happens from ext4_free_ioend()). 146a115f749SJan Kara */ 14728a535f9SDmitry Monakhov static int ext4_end_io(ext4_io_end_t *io) 148bd2d0210STheodore Ts'o { 149bd2d0210STheodore Ts'o struct inode *inode = io->inode; 150bd2d0210STheodore Ts'o loff_t offset = io->offset; 151bd2d0210STheodore Ts'o ssize_t size = io->size; 1526b523df4SJan Kara handle_t *handle = io->handle; 153bd2d0210STheodore Ts'o int ret = 0; 154bd2d0210STheodore Ts'o 155bd2d0210STheodore Ts'o ext4_debug("ext4_end_io_nolock: io 0x%p from inode %lu,list->next 0x%p," 156bd2d0210STheodore Ts'o "list->prev 0x%p\n", 157bd2d0210STheodore Ts'o io, inode->i_ino, io->list.next, io->list.prev); 158bd2d0210STheodore Ts'o 1596b523df4SJan Kara io->handle = NULL; /* Following call will use up the handle */ 1606b523df4SJan Kara ret = ext4_convert_unwritten_extents(handle, inode, offset, size); 161bd2d0210STheodore Ts'o if (ret < 0) { 162b82e384cSTheodore Ts'o ext4_msg(inode->i_sb, KERN_EMERG, 163b82e384cSTheodore Ts'o "failed to convert unwritten extents to written " 164b82e384cSTheodore Ts'o "extents -- potential data loss! " 165b82e384cSTheodore Ts'o "(inode %lu, offset %llu, size %zd, error %d)", 166b82e384cSTheodore Ts'o inode->i_ino, offset, size, ret); 167bd2d0210STheodore Ts'o } 16897a851edSJan Kara ext4_clear_io_unwritten_flag(io); 16997a851edSJan Kara ext4_release_io_end(io); 170bd2d0210STheodore Ts'o return ret; 171bd2d0210STheodore Ts'o } 172bd2d0210STheodore Ts'o 1732e8fa54eSJan Kara static void dump_completed_IO(struct inode *inode, struct list_head *head) 17428a535f9SDmitry Monakhov { 17528a535f9SDmitry Monakhov #ifdef EXT4FS_DEBUG 17628a535f9SDmitry Monakhov struct list_head *cur, *before, *after; 17728a535f9SDmitry Monakhov ext4_io_end_t *io, *io0, *io1; 17828a535f9SDmitry Monakhov 1792e8fa54eSJan Kara if (list_empty(head)) 18028a535f9SDmitry Monakhov return; 18128a535f9SDmitry Monakhov 1822e8fa54eSJan Kara ext4_debug("Dump inode %lu completed io list\n", inode->i_ino); 1832e8fa54eSJan Kara list_for_each_entry(io, head, list) { 18428a535f9SDmitry Monakhov cur = &io->list; 18528a535f9SDmitry Monakhov before = cur->prev; 18628a535f9SDmitry Monakhov io0 = container_of(before, ext4_io_end_t, list); 18728a535f9SDmitry Monakhov after = cur->next; 18828a535f9SDmitry Monakhov io1 = container_of(after, ext4_io_end_t, list); 18928a535f9SDmitry Monakhov 19028a535f9SDmitry Monakhov ext4_debug("io 0x%p from inode %lu,prev 0x%p,next 0x%p\n", 19128a535f9SDmitry Monakhov io, inode->i_ino, io0, io1); 19228a535f9SDmitry Monakhov } 19328a535f9SDmitry Monakhov #endif 19428a535f9SDmitry Monakhov } 19528a535f9SDmitry Monakhov 19628a535f9SDmitry Monakhov /* Add the io_end to per-inode completed end_io list. */ 19797a851edSJan Kara static void ext4_add_complete_io(ext4_io_end_t *io_end) 19828a535f9SDmitry Monakhov { 19928a535f9SDmitry Monakhov struct ext4_inode_info *ei = EXT4_I(io_end->inode); 20078371a45SJan Kara struct ext4_sb_info *sbi = EXT4_SB(io_end->inode->i_sb); 20128a535f9SDmitry Monakhov struct workqueue_struct *wq; 20228a535f9SDmitry Monakhov unsigned long flags; 20328a535f9SDmitry Monakhov 2047b7a8665SChristoph Hellwig /* Only reserved conversions from writeback should enter here */ 2057b7a8665SChristoph Hellwig WARN_ON(!(io_end->flag & EXT4_IO_END_UNWRITTEN)); 20678371a45SJan Kara WARN_ON(!io_end->handle && sbi->s_journal); 20728a535f9SDmitry Monakhov spin_lock_irqsave(&ei->i_completed_io_lock, flags); 20878371a45SJan Kara wq = sbi->rsv_conversion_wq; 2092e8fa54eSJan Kara if (list_empty(&ei->i_rsv_conversion_list)) 2102e8fa54eSJan Kara queue_work(wq, &ei->i_rsv_conversion_work); 2112e8fa54eSJan Kara list_add_tail(&io_end->list, &ei->i_rsv_conversion_list); 21228a535f9SDmitry Monakhov spin_unlock_irqrestore(&ei->i_completed_io_lock, flags); 21328a535f9SDmitry Monakhov } 21428a535f9SDmitry Monakhov 2152e8fa54eSJan Kara static int ext4_do_flush_completed_IO(struct inode *inode, 2162e8fa54eSJan Kara struct list_head *head) 21728a535f9SDmitry Monakhov { 21828a535f9SDmitry Monakhov ext4_io_end_t *io; 219002bd7faSJan Kara struct list_head unwritten; 22028a535f9SDmitry Monakhov unsigned long flags; 22128a535f9SDmitry Monakhov struct ext4_inode_info *ei = EXT4_I(inode); 22228a535f9SDmitry Monakhov int err, ret = 0; 22328a535f9SDmitry Monakhov 22428a535f9SDmitry Monakhov spin_lock_irqsave(&ei->i_completed_io_lock, flags); 2252e8fa54eSJan Kara dump_completed_IO(inode, head); 2262e8fa54eSJan Kara list_replace_init(head, &unwritten); 22728a535f9SDmitry Monakhov spin_unlock_irqrestore(&ei->i_completed_io_lock, flags); 22828a535f9SDmitry Monakhov 22928a535f9SDmitry Monakhov while (!list_empty(&unwritten)) { 23028a535f9SDmitry Monakhov io = list_entry(unwritten.next, ext4_io_end_t, list); 23128a535f9SDmitry Monakhov BUG_ON(!(io->flag & EXT4_IO_END_UNWRITTEN)); 23228a535f9SDmitry Monakhov list_del_init(&io->list); 23328a535f9SDmitry Monakhov 23428a535f9SDmitry Monakhov err = ext4_end_io(io); 23528a535f9SDmitry Monakhov if (unlikely(!ret && err)) 23628a535f9SDmitry Monakhov ret = err; 23728a535f9SDmitry Monakhov } 23828a535f9SDmitry Monakhov return ret; 23928a535f9SDmitry Monakhov } 24028a535f9SDmitry Monakhov 241bd2d0210STheodore Ts'o /* 2422e8fa54eSJan Kara * work on completed IO, to convert unwritten extents to extents 243bd2d0210STheodore Ts'o */ 2442e8fa54eSJan Kara void ext4_end_io_rsv_work(struct work_struct *work) 245bd2d0210STheodore Ts'o { 24684c17543SJan Kara struct ext4_inode_info *ei = container_of(work, struct ext4_inode_info, 2472e8fa54eSJan Kara i_rsv_conversion_work); 2482e8fa54eSJan Kara ext4_do_flush_completed_IO(&ei->vfs_inode, &ei->i_rsv_conversion_list); 2492e8fa54eSJan Kara } 2502e8fa54eSJan Kara 251bd2d0210STheodore Ts'o ext4_io_end_t *ext4_init_io_end(struct inode *inode, gfp_t flags) 252bd2d0210STheodore Ts'o { 253b17b35ecSJesper Juhl ext4_io_end_t *io = kmem_cache_zalloc(io_end_cachep, flags); 254bd2d0210STheodore Ts'o if (io) { 255f7ad6d2eSTheodore Ts'o io->inode = inode; 256bd2d0210STheodore Ts'o INIT_LIST_HEAD(&io->list); 25797a851edSJan Kara atomic_set(&io->count, 1); 258bd2d0210STheodore Ts'o } 259bd2d0210STheodore Ts'o return io; 260bd2d0210STheodore Ts'o } 261bd2d0210STheodore Ts'o 26297a851edSJan Kara void ext4_put_io_end_defer(ext4_io_end_t *io_end) 26397a851edSJan Kara { 26497a851edSJan Kara if (atomic_dec_and_test(&io_end->count)) { 26597a851edSJan Kara if (!(io_end->flag & EXT4_IO_END_UNWRITTEN) || !io_end->size) { 26697a851edSJan Kara ext4_release_io_end(io_end); 26797a851edSJan Kara return; 26897a851edSJan Kara } 26997a851edSJan Kara ext4_add_complete_io(io_end); 27097a851edSJan Kara } 27197a851edSJan Kara } 27297a851edSJan Kara 27397a851edSJan Kara int ext4_put_io_end(ext4_io_end_t *io_end) 27497a851edSJan Kara { 27597a851edSJan Kara int err = 0; 27697a851edSJan Kara 27797a851edSJan Kara if (atomic_dec_and_test(&io_end->count)) { 27897a851edSJan Kara if (io_end->flag & EXT4_IO_END_UNWRITTEN) { 2796b523df4SJan Kara err = ext4_convert_unwritten_extents(io_end->handle, 2806b523df4SJan Kara io_end->inode, io_end->offset, 2816b523df4SJan Kara io_end->size); 2826b523df4SJan Kara io_end->handle = NULL; 28397a851edSJan Kara ext4_clear_io_unwritten_flag(io_end); 28497a851edSJan Kara } 28597a851edSJan Kara ext4_release_io_end(io_end); 28697a851edSJan Kara } 28797a851edSJan Kara return err; 28897a851edSJan Kara } 28997a851edSJan Kara 29097a851edSJan Kara ext4_io_end_t *ext4_get_io_end(ext4_io_end_t *io_end) 29197a851edSJan Kara { 29297a851edSJan Kara atomic_inc(&io_end->count); 29397a851edSJan Kara return io_end; 29497a851edSJan Kara } 29597a851edSJan Kara 296822dbba3SJan Kara /* BIO completion function for page writeback */ 2974246a0b6SChristoph Hellwig static void ext4_end_bio(struct bio *bio) 298bd2d0210STheodore Ts'o { 299bd2d0210STheodore Ts'o ext4_io_end_t *io_end = bio->bi_private; 3004f024f37SKent Overstreet sector_t bi_sector = bio->bi_iter.bi_sector; 301bd2d0210STheodore Ts'o 302bd2d0210STheodore Ts'o BUG_ON(!io_end); 303bd2d0210STheodore Ts'o bio->bi_end_io = NULL; 3040058f965SJan Kara 3054246a0b6SChristoph Hellwig if (bio->bi_error) { 306b0857d30SJan Kara struct inode *inode = io_end->inode; 307b0857d30SJan Kara 3089503c67cSMatthew Wilcox ext4_warning(inode->i_sb, "I/O error %d writing to inode %lu " 309f7ad6d2eSTheodore Ts'o "(offset %llu size %ld starting block %llu)", 3104246a0b6SChristoph Hellwig bio->bi_error, inode->i_ino, 311f7ad6d2eSTheodore Ts'o (unsigned long long) io_end->offset, 312f7ad6d2eSTheodore Ts'o (long) io_end->size, 313f7ad6d2eSTheodore Ts'o (unsigned long long) 314d50bdd5aSCurt Wohlgemuth bi_sector >> (inode->i_blkbits - 9)); 3154246a0b6SChristoph Hellwig mapping_set_error(inode->i_mapping, bio->bi_error); 316f7ad6d2eSTheodore Ts'o } 317822dbba3SJan Kara 318822dbba3SJan Kara if (io_end->flag & EXT4_IO_END_UNWRITTEN) { 319822dbba3SJan Kara /* 320822dbba3SJan Kara * Link bio into list hanging from io_end. We have to do it 321822dbba3SJan Kara * atomically as bio completions can be racing against each 322822dbba3SJan Kara * other. 323822dbba3SJan Kara */ 324822dbba3SJan Kara bio->bi_private = xchg(&io_end->bio, bio); 32597a851edSJan Kara ext4_put_io_end_defer(io_end); 326822dbba3SJan Kara } else { 327822dbba3SJan Kara /* 328822dbba3SJan Kara * Drop io_end reference early. Inode can get freed once 329822dbba3SJan Kara * we finish the bio. 330822dbba3SJan Kara */ 331822dbba3SJan Kara ext4_put_io_end_defer(io_end); 332822dbba3SJan Kara ext4_finish_bio(bio); 333822dbba3SJan Kara bio_put(bio); 334822dbba3SJan Kara } 335bd2d0210STheodore Ts'o } 336bd2d0210STheodore Ts'o 337bd2d0210STheodore Ts'o void ext4_io_submit(struct ext4_io_submit *io) 338bd2d0210STheodore Ts'o { 339bd2d0210STheodore Ts'o struct bio *bio = io->io_bio; 340bd2d0210STheodore Ts'o 341bd2d0210STheodore Ts'o if (bio) { 3425a33911fSTejun Heo int io_op = io->io_wbc->sync_mode == WB_SYNC_ALL ? 3435a33911fSTejun Heo WRITE_SYNC : WRITE; 344bd2d0210STheodore Ts'o bio_get(io->io_bio); 3455a33911fSTejun Heo submit_bio(io_op, io->io_bio); 346bd2d0210STheodore Ts'o bio_put(io->io_bio); 347bd2d0210STheodore Ts'o } 3487dc57615SPeter Huewe io->io_bio = NULL; 34997a851edSJan Kara } 35097a851edSJan Kara 35197a851edSJan Kara void ext4_io_submit_init(struct ext4_io_submit *io, 35297a851edSJan Kara struct writeback_control *wbc) 35397a851edSJan Kara { 3545a33911fSTejun Heo io->io_wbc = wbc; 35597a851edSJan Kara io->io_bio = NULL; 3567dc57615SPeter Huewe io->io_end = NULL; 357bd2d0210STheodore Ts'o } 358bd2d0210STheodore Ts'o 35997a851edSJan Kara static int io_submit_init_bio(struct ext4_io_submit *io, 360bd2d0210STheodore Ts'o struct buffer_head *bh) 361bd2d0210STheodore Ts'o { 362bd2d0210STheodore Ts'o struct bio *bio; 363bd2d0210STheodore Ts'o 364b54ffb73SKent Overstreet bio = bio_alloc(GFP_NOIO, BIO_MAX_PAGES); 365a1d8d9a7STheodore Ts'o if (!bio) 366a1d8d9a7STheodore Ts'o return -ENOMEM; 367001e4a87STejun Heo wbc_init_bio(io->io_wbc, bio); 3684f024f37SKent Overstreet bio->bi_iter.bi_sector = bh->b_blocknr * (bh->b_size >> 9); 369bd2d0210STheodore Ts'o bio->bi_bdev = bh->b_bdev; 370bd2d0210STheodore Ts'o bio->bi_end_io = ext4_end_bio; 37197a851edSJan Kara bio->bi_private = ext4_get_io_end(io->io_end); 372bd2d0210STheodore Ts'o io->io_bio = bio; 373bd2d0210STheodore Ts'o io->io_next_block = bh->b_blocknr; 374bd2d0210STheodore Ts'o return 0; 375bd2d0210STheodore Ts'o } 376bd2d0210STheodore Ts'o 377bd2d0210STheodore Ts'o static int io_submit_add_bh(struct ext4_io_submit *io, 378bd2d0210STheodore Ts'o struct inode *inode, 3792058f83aSMichael Halcrow struct page *page, 380bd2d0210STheodore Ts'o struct buffer_head *bh) 381bd2d0210STheodore Ts'o { 382bd2d0210STheodore Ts'o int ret; 383bd2d0210STheodore Ts'o 384bd2d0210STheodore Ts'o if (io->io_bio && bh->b_blocknr != io->io_next_block) { 385bd2d0210STheodore Ts'o submit_and_retry: 386bd2d0210STheodore Ts'o ext4_io_submit(io); 387bd2d0210STheodore Ts'o } 388bd2d0210STheodore Ts'o if (io->io_bio == NULL) { 38997a851edSJan Kara ret = io_submit_init_bio(io, bh); 390bd2d0210STheodore Ts'o if (ret) 391bd2d0210STheodore Ts'o return ret; 392bd2d0210STheodore Ts'o } 3932058f83aSMichael Halcrow ret = bio_add_page(io->io_bio, page, bh->b_size, bh_offset(bh)); 394a549984bSTheodore Ts'o if (ret != bh->b_size) 395a549984bSTheodore Ts'o goto submit_and_retry; 396001e4a87STejun Heo wbc_account_io(io->io_wbc, page, bh->b_size); 39797a851edSJan Kara io->io_next_block++; 398bd2d0210STheodore Ts'o return 0; 399bd2d0210STheodore Ts'o } 400bd2d0210STheodore Ts'o 401bd2d0210STheodore Ts'o int ext4_bio_write_page(struct ext4_io_submit *io, 402bd2d0210STheodore Ts'o struct page *page, 403bd2d0210STheodore Ts'o int len, 4041c8349a1SNamjae Jeon struct writeback_control *wbc, 4051c8349a1SNamjae Jeon bool keep_towrite) 406bd2d0210STheodore Ts'o { 4072058f83aSMichael Halcrow struct page *data_page = NULL; 408bd2d0210STheodore Ts'o struct inode *inode = page->mapping->host; 4090058f965SJan Kara unsigned block_start, blocksize; 410bd2d0210STheodore Ts'o struct buffer_head *bh, *head; 411bd2d0210STheodore Ts'o int ret = 0; 4120058f965SJan Kara int nr_submitted = 0; 413937d7b84STheodore Ts'o int nr_to_submit = 0; 414bd2d0210STheodore Ts'o 415bd2d0210STheodore Ts'o blocksize = 1 << inode->i_blkbits; 416bd2d0210STheodore Ts'o 417d50bdd5aSCurt Wohlgemuth BUG_ON(!PageLocked(page)); 418bd2d0210STheodore Ts'o BUG_ON(PageWriteback(page)); 419bd2d0210STheodore Ts'o 4201c8349a1SNamjae Jeon if (keep_towrite) 4211c8349a1SNamjae Jeon set_page_writeback_keepwrite(page); 4221c8349a1SNamjae Jeon else 423a54aa761STheodore Ts'o set_page_writeback(page); 424a54aa761STheodore Ts'o ClearPageError(page); 425bd2d0210STheodore Ts'o 4260058f965SJan Kara /* 427f8409abdSLinus Torvalds * Comments copied from block_write_full_page: 428eeece469SJan Kara * 429eeece469SJan Kara * The page straddles i_size. It must be zeroed out on each and every 430eeece469SJan Kara * writepage invocation because it may be mmapped. "A file is mapped 431eeece469SJan Kara * in multiples of the page size. For a file that is not a multiple of 432eeece469SJan Kara * the page size, the remaining memory is zeroed when mapped, and 433eeece469SJan Kara * writes to that region are not written out to the file." 434eeece469SJan Kara */ 435*09cbfeafSKirill A. Shutemov if (len < PAGE_SIZE) 436*09cbfeafSKirill A. Shutemov zero_user_segment(page, len, PAGE_SIZE); 437eeece469SJan Kara /* 4380058f965SJan Kara * In the first loop we prepare and mark buffers to submit. We have to 4390058f965SJan Kara * mark all buffers in the page before submitting so that 4400058f965SJan Kara * end_page_writeback() cannot be called from ext4_bio_end_io() when IO 4410058f965SJan Kara * on the first buffer finishes and we are still working on submitting 4420058f965SJan Kara * the second buffer. 4430058f965SJan Kara */ 4440058f965SJan Kara bh = head = page_buffers(page); 4450058f965SJan Kara do { 4460058f965SJan Kara block_start = bh_offset(bh); 447bd2d0210STheodore Ts'o if (block_start >= len) { 448bd2d0210STheodore Ts'o clear_buffer_dirty(bh); 449bd2d0210STheodore Ts'o set_buffer_uptodate(bh); 450bd2d0210STheodore Ts'o continue; 451bd2d0210STheodore Ts'o } 4528a850c3fSJan Kara if (!buffer_dirty(bh) || buffer_delay(bh) || 4538a850c3fSJan Kara !buffer_mapped(bh) || buffer_unwritten(bh)) { 4548a850c3fSJan Kara /* A hole? We can safely clear the dirty bit */ 4558a850c3fSJan Kara if (!buffer_mapped(bh)) 4568a850c3fSJan Kara clear_buffer_dirty(bh); 4578a850c3fSJan Kara if (io->io_bio) 4588a850c3fSJan Kara ext4_io_submit(io); 4598a850c3fSJan Kara continue; 4608a850c3fSJan Kara } 4610058f965SJan Kara if (buffer_new(bh)) { 4620058f965SJan Kara clear_buffer_new(bh); 4630058f965SJan Kara unmap_underlying_metadata(bh->b_bdev, bh->b_blocknr); 4640058f965SJan Kara } 4650058f965SJan Kara set_buffer_async_write(bh); 466937d7b84STheodore Ts'o nr_to_submit++; 4670058f965SJan Kara } while ((bh = bh->b_this_page) != head); 4680058f965SJan Kara 4690058f965SJan Kara bh = head = page_buffers(page); 4702058f83aSMichael Halcrow 471937d7b84STheodore Ts'o if (ext4_encrypted_inode(inode) && S_ISREG(inode->i_mode) && 472937d7b84STheodore Ts'o nr_to_submit) { 4732058f83aSMichael Halcrow data_page = ext4_encrypt(inode, page); 4742058f83aSMichael Halcrow if (IS_ERR(data_page)) { 4752058f83aSMichael Halcrow ret = PTR_ERR(data_page); 4762058f83aSMichael Halcrow data_page = NULL; 4772058f83aSMichael Halcrow goto out; 4782058f83aSMichael Halcrow } 4792058f83aSMichael Halcrow } 4802058f83aSMichael Halcrow 4812058f83aSMichael Halcrow /* Now submit buffers to write */ 4820058f965SJan Kara do { 4830058f965SJan Kara if (!buffer_async_write(bh)) 4840058f965SJan Kara continue; 4852058f83aSMichael Halcrow ret = io_submit_add_bh(io, inode, 4862058f83aSMichael Halcrow data_page ? data_page : page, bh); 487bd2d0210STheodore Ts'o if (ret) { 488bd2d0210STheodore Ts'o /* 489bd2d0210STheodore Ts'o * We only get here on ENOMEM. Not much else 490bd2d0210STheodore Ts'o * we can do but mark the page as dirty, and 491bd2d0210STheodore Ts'o * better luck next time. 492bd2d0210STheodore Ts'o */ 493bd2d0210STheodore Ts'o break; 494bd2d0210STheodore Ts'o } 4950058f965SJan Kara nr_submitted++; 4961ae48a63SJan Kara clear_buffer_dirty(bh); 4970058f965SJan Kara } while ((bh = bh->b_this_page) != head); 4980058f965SJan Kara 4990058f965SJan Kara /* Error stopped previous loop? Clean up buffers... */ 5000058f965SJan Kara if (ret) { 5012058f83aSMichael Halcrow out: 5022058f83aSMichael Halcrow if (data_page) 5032058f83aSMichael Halcrow ext4_restore_control_page(data_page); 5042058f83aSMichael Halcrow printk_ratelimited(KERN_ERR "%s: ret = %d\n", __func__, ret); 5052058f83aSMichael Halcrow redirty_page_for_writepage(wbc, page); 5060058f965SJan Kara do { 5070058f965SJan Kara clear_buffer_async_write(bh); 5080058f965SJan Kara bh = bh->b_this_page; 5090058f965SJan Kara } while (bh != head); 510bd2d0210STheodore Ts'o } 511bd2d0210STheodore Ts'o unlock_page(page); 5120058f965SJan Kara /* Nothing submitted - we have to end page writeback */ 5130058f965SJan Kara if (!nr_submitted) 5140058f965SJan Kara end_page_writeback(page); 515bd2d0210STheodore Ts'o return ret; 516bd2d0210STheodore Ts'o } 517