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 { 55b0857d30SJan Kara char b[BDEVNAME_SIZE]; 56e8974c39SAnatol Pomozov printk_ratelimited(KERN_ERR "Buffer I/O error on device %s, logical block %llu\n", 57b0857d30SJan Kara bdevname(bh->b_bdev, b), 58b0857d30SJan Kara (unsigned long long)bh->b_blocknr); 59b0857d30SJan Kara } 60b0857d30SJan Kara 61b0857d30SJan Kara static void ext4_finish_bio(struct bio *bio) 62b0857d30SJan Kara { 63b0857d30SJan Kara int i; 64b0857d30SJan Kara int error = !test_bit(BIO_UPTODATE, &bio->bi_flags); 652c30c71bSKent Overstreet struct bio_vec *bvec; 66b0857d30SJan Kara 672c30c71bSKent Overstreet bio_for_each_segment_all(bvec, bio, i) { 68b0857d30SJan Kara struct page *page = bvec->bv_page; 692058f83aSMichael Halcrow #ifdef CONFIG_EXT4_FS_ENCRYPTION 702058f83aSMichael Halcrow struct page *data_page = NULL; 712058f83aSMichael Halcrow struct ext4_crypto_ctx *ctx = NULL; 722058f83aSMichael Halcrow #endif 73b0857d30SJan Kara struct buffer_head *bh, *head; 74b0857d30SJan Kara unsigned bio_start = bvec->bv_offset; 75b0857d30SJan Kara unsigned bio_end = bio_start + bvec->bv_len; 76b0857d30SJan Kara unsigned under_io = 0; 77b0857d30SJan Kara unsigned long flags; 78b0857d30SJan Kara 79b0857d30SJan Kara if (!page) 80b0857d30SJan Kara continue; 81b0857d30SJan Kara 822058f83aSMichael Halcrow #ifdef CONFIG_EXT4_FS_ENCRYPTION 832058f83aSMichael Halcrow if (!page->mapping) { 842058f83aSMichael Halcrow /* The bounce data pages are unmapped. */ 852058f83aSMichael Halcrow data_page = page; 862058f83aSMichael Halcrow ctx = (struct ext4_crypto_ctx *)page_private(data_page); 87614def70STheodore Ts'o page = ctx->w.control_page; 882058f83aSMichael Halcrow } 892058f83aSMichael Halcrow #endif 902058f83aSMichael Halcrow 91b0857d30SJan Kara if (error) { 92b0857d30SJan Kara SetPageError(page); 93b0857d30SJan Kara set_bit(AS_EIO, &page->mapping->flags); 94b0857d30SJan Kara } 95b0857d30SJan Kara bh = head = page_buffers(page); 96b0857d30SJan Kara /* 97b0857d30SJan Kara * We check all buffers in the page under BH_Uptodate_Lock 98b0857d30SJan Kara * to avoid races with other end io clearing async_write flags 99b0857d30SJan Kara */ 100b0857d30SJan Kara local_irq_save(flags); 101b0857d30SJan Kara bit_spin_lock(BH_Uptodate_Lock, &head->b_state); 102b0857d30SJan Kara do { 103b0857d30SJan Kara if (bh_offset(bh) < bio_start || 104b0857d30SJan Kara bh_offset(bh) + bh->b_size > bio_end) { 105b0857d30SJan Kara if (buffer_async_write(bh)) 106b0857d30SJan Kara under_io++; 107b0857d30SJan Kara continue; 108b0857d30SJan Kara } 109b0857d30SJan Kara clear_buffer_async_write(bh); 110b0857d30SJan Kara if (error) 111b0857d30SJan Kara buffer_io_error(bh); 112b0857d30SJan Kara } while ((bh = bh->b_this_page) != head); 113b0857d30SJan Kara bit_spin_unlock(BH_Uptodate_Lock, &head->b_state); 114b0857d30SJan Kara local_irq_restore(flags); 1152058f83aSMichael Halcrow if (!under_io) { 1162058f83aSMichael Halcrow #ifdef CONFIG_EXT4_FS_ENCRYPTION 1172058f83aSMichael Halcrow if (ctx) 1182058f83aSMichael Halcrow ext4_restore_control_page(data_page); 1192058f83aSMichael Halcrow #endif 120b0857d30SJan Kara end_page_writeback(page); 121b0857d30SJan Kara } 122b0857d30SJan Kara } 1232058f83aSMichael Halcrow } 124b0857d30SJan Kara 12597a851edSJan Kara static void ext4_release_io_end(ext4_io_end_t *io_end) 126bd2d0210STheodore Ts'o { 127b0857d30SJan Kara struct bio *bio, *next_bio; 128b0857d30SJan Kara 12997a851edSJan Kara BUG_ON(!list_empty(&io_end->list)); 13097a851edSJan Kara BUG_ON(io_end->flag & EXT4_IO_END_UNWRITTEN); 1316b523df4SJan Kara WARN_ON(io_end->handle); 132bd2d0210STheodore Ts'o 13397a851edSJan Kara if (atomic_dec_and_test(&EXT4_I(io_end->inode)->i_ioend_count)) 13497a851edSJan Kara wake_up_all(ext4_ioend_wq(io_end->inode)); 135b0857d30SJan Kara 136b0857d30SJan Kara for (bio = io_end->bio; bio; bio = next_bio) { 137b0857d30SJan Kara next_bio = bio->bi_private; 138b0857d30SJan Kara ext4_finish_bio(bio); 139b0857d30SJan Kara bio_put(bio); 140b0857d30SJan Kara } 14197a851edSJan Kara kmem_cache_free(io_end_cachep, io_end); 14297a851edSJan Kara } 14397a851edSJan Kara 14497a851edSJan Kara static void ext4_clear_io_unwritten_flag(ext4_io_end_t *io_end) 14597a851edSJan Kara { 14697a851edSJan Kara struct inode *inode = io_end->inode; 14797a851edSJan Kara 14897a851edSJan Kara io_end->flag &= ~EXT4_IO_END_UNWRITTEN; 14997a851edSJan Kara /* Wake up anyone waiting on unwritten extent conversion */ 15097a851edSJan Kara if (atomic_dec_and_test(&EXT4_I(inode)->i_unwritten)) 15197a851edSJan Kara wake_up_all(ext4_ioend_wq(inode)); 152bd2d0210STheodore Ts'o } 153bd2d0210STheodore Ts'o 154a115f749SJan Kara /* 155a115f749SJan Kara * Check a range of space and convert unwritten extents to written. Note that 156a115f749SJan Kara * we are protected from truncate touching same part of extent tree by the 157a115f749SJan Kara * fact that truncate code waits for all DIO to finish (thus exclusion from 158a115f749SJan Kara * direct IO is achieved) and also waits for PageWriteback bits. Thus we 159a115f749SJan Kara * cannot get to ext4_ext_truncate() before all IOs overlapping that range are 160a115f749SJan Kara * completed (happens from ext4_free_ioend()). 161a115f749SJan Kara */ 16228a535f9SDmitry Monakhov static int ext4_end_io(ext4_io_end_t *io) 163bd2d0210STheodore Ts'o { 164bd2d0210STheodore Ts'o struct inode *inode = io->inode; 165bd2d0210STheodore Ts'o loff_t offset = io->offset; 166bd2d0210STheodore Ts'o ssize_t size = io->size; 1676b523df4SJan Kara handle_t *handle = io->handle; 168bd2d0210STheodore Ts'o int ret = 0; 169bd2d0210STheodore Ts'o 170bd2d0210STheodore Ts'o ext4_debug("ext4_end_io_nolock: io 0x%p from inode %lu,list->next 0x%p," 171bd2d0210STheodore Ts'o "list->prev 0x%p\n", 172bd2d0210STheodore Ts'o io, inode->i_ino, io->list.next, io->list.prev); 173bd2d0210STheodore Ts'o 1746b523df4SJan Kara io->handle = NULL; /* Following call will use up the handle */ 1756b523df4SJan Kara ret = ext4_convert_unwritten_extents(handle, inode, offset, size); 176bd2d0210STheodore Ts'o if (ret < 0) { 177b82e384cSTheodore Ts'o ext4_msg(inode->i_sb, KERN_EMERG, 178b82e384cSTheodore Ts'o "failed to convert unwritten extents to written " 179b82e384cSTheodore Ts'o "extents -- potential data loss! " 180b82e384cSTheodore Ts'o "(inode %lu, offset %llu, size %zd, error %d)", 181b82e384cSTheodore Ts'o inode->i_ino, offset, size, ret); 182bd2d0210STheodore Ts'o } 18397a851edSJan Kara ext4_clear_io_unwritten_flag(io); 18497a851edSJan Kara ext4_release_io_end(io); 185bd2d0210STheodore Ts'o return ret; 186bd2d0210STheodore Ts'o } 187bd2d0210STheodore Ts'o 1882e8fa54eSJan Kara static void dump_completed_IO(struct inode *inode, struct list_head *head) 18928a535f9SDmitry Monakhov { 19028a535f9SDmitry Monakhov #ifdef EXT4FS_DEBUG 19128a535f9SDmitry Monakhov struct list_head *cur, *before, *after; 19228a535f9SDmitry Monakhov ext4_io_end_t *io, *io0, *io1; 19328a535f9SDmitry Monakhov 1942e8fa54eSJan Kara if (list_empty(head)) 19528a535f9SDmitry Monakhov return; 19628a535f9SDmitry Monakhov 1972e8fa54eSJan Kara ext4_debug("Dump inode %lu completed io list\n", inode->i_ino); 1982e8fa54eSJan Kara list_for_each_entry(io, head, list) { 19928a535f9SDmitry Monakhov cur = &io->list; 20028a535f9SDmitry Monakhov before = cur->prev; 20128a535f9SDmitry Monakhov io0 = container_of(before, ext4_io_end_t, list); 20228a535f9SDmitry Monakhov after = cur->next; 20328a535f9SDmitry Monakhov io1 = container_of(after, ext4_io_end_t, list); 20428a535f9SDmitry Monakhov 20528a535f9SDmitry Monakhov ext4_debug("io 0x%p from inode %lu,prev 0x%p,next 0x%p\n", 20628a535f9SDmitry Monakhov io, inode->i_ino, io0, io1); 20728a535f9SDmitry Monakhov } 20828a535f9SDmitry Monakhov #endif 20928a535f9SDmitry Monakhov } 21028a535f9SDmitry Monakhov 21128a535f9SDmitry Monakhov /* Add the io_end to per-inode completed end_io list. */ 21297a851edSJan Kara static void ext4_add_complete_io(ext4_io_end_t *io_end) 21328a535f9SDmitry Monakhov { 21428a535f9SDmitry Monakhov struct ext4_inode_info *ei = EXT4_I(io_end->inode); 21578371a45SJan Kara struct ext4_sb_info *sbi = EXT4_SB(io_end->inode->i_sb); 21628a535f9SDmitry Monakhov struct workqueue_struct *wq; 21728a535f9SDmitry Monakhov unsigned long flags; 21828a535f9SDmitry Monakhov 2197b7a8665SChristoph Hellwig /* Only reserved conversions from writeback should enter here */ 2207b7a8665SChristoph Hellwig WARN_ON(!(io_end->flag & EXT4_IO_END_UNWRITTEN)); 22178371a45SJan Kara WARN_ON(!io_end->handle && sbi->s_journal); 22228a535f9SDmitry Monakhov spin_lock_irqsave(&ei->i_completed_io_lock, flags); 22378371a45SJan Kara wq = sbi->rsv_conversion_wq; 2242e8fa54eSJan Kara if (list_empty(&ei->i_rsv_conversion_list)) 2252e8fa54eSJan Kara queue_work(wq, &ei->i_rsv_conversion_work); 2262e8fa54eSJan Kara list_add_tail(&io_end->list, &ei->i_rsv_conversion_list); 22728a535f9SDmitry Monakhov spin_unlock_irqrestore(&ei->i_completed_io_lock, flags); 22828a535f9SDmitry Monakhov } 22928a535f9SDmitry Monakhov 2302e8fa54eSJan Kara static int ext4_do_flush_completed_IO(struct inode *inode, 2312e8fa54eSJan Kara struct list_head *head) 23228a535f9SDmitry Monakhov { 23328a535f9SDmitry Monakhov ext4_io_end_t *io; 234002bd7faSJan Kara struct list_head unwritten; 23528a535f9SDmitry Monakhov unsigned long flags; 23628a535f9SDmitry Monakhov struct ext4_inode_info *ei = EXT4_I(inode); 23728a535f9SDmitry Monakhov int err, ret = 0; 23828a535f9SDmitry Monakhov 23928a535f9SDmitry Monakhov spin_lock_irqsave(&ei->i_completed_io_lock, flags); 2402e8fa54eSJan Kara dump_completed_IO(inode, head); 2412e8fa54eSJan Kara list_replace_init(head, &unwritten); 24228a535f9SDmitry Monakhov spin_unlock_irqrestore(&ei->i_completed_io_lock, flags); 24328a535f9SDmitry Monakhov 24428a535f9SDmitry Monakhov while (!list_empty(&unwritten)) { 24528a535f9SDmitry Monakhov io = list_entry(unwritten.next, ext4_io_end_t, list); 24628a535f9SDmitry Monakhov BUG_ON(!(io->flag & EXT4_IO_END_UNWRITTEN)); 24728a535f9SDmitry Monakhov list_del_init(&io->list); 24828a535f9SDmitry Monakhov 24928a535f9SDmitry Monakhov err = ext4_end_io(io); 25028a535f9SDmitry Monakhov if (unlikely(!ret && err)) 25128a535f9SDmitry Monakhov ret = err; 25228a535f9SDmitry Monakhov } 25328a535f9SDmitry Monakhov return ret; 25428a535f9SDmitry Monakhov } 25528a535f9SDmitry Monakhov 256bd2d0210STheodore Ts'o /* 2572e8fa54eSJan Kara * work on completed IO, to convert unwritten extents to extents 258bd2d0210STheodore Ts'o */ 2592e8fa54eSJan Kara void ext4_end_io_rsv_work(struct work_struct *work) 260bd2d0210STheodore Ts'o { 26184c17543SJan Kara struct ext4_inode_info *ei = container_of(work, struct ext4_inode_info, 2622e8fa54eSJan Kara i_rsv_conversion_work); 2632e8fa54eSJan Kara ext4_do_flush_completed_IO(&ei->vfs_inode, &ei->i_rsv_conversion_list); 2642e8fa54eSJan Kara } 2652e8fa54eSJan Kara 266bd2d0210STheodore Ts'o ext4_io_end_t *ext4_init_io_end(struct inode *inode, gfp_t flags) 267bd2d0210STheodore Ts'o { 268b17b35ecSJesper Juhl ext4_io_end_t *io = kmem_cache_zalloc(io_end_cachep, flags); 269bd2d0210STheodore Ts'o if (io) { 270f7ad6d2eSTheodore Ts'o atomic_inc(&EXT4_I(inode)->i_ioend_count); 271f7ad6d2eSTheodore Ts'o io->inode = inode; 272bd2d0210STheodore Ts'o INIT_LIST_HEAD(&io->list); 27397a851edSJan Kara atomic_set(&io->count, 1); 274bd2d0210STheodore Ts'o } 275bd2d0210STheodore Ts'o return io; 276bd2d0210STheodore Ts'o } 277bd2d0210STheodore Ts'o 27897a851edSJan Kara void ext4_put_io_end_defer(ext4_io_end_t *io_end) 27997a851edSJan Kara { 28097a851edSJan Kara if (atomic_dec_and_test(&io_end->count)) { 28197a851edSJan Kara if (!(io_end->flag & EXT4_IO_END_UNWRITTEN) || !io_end->size) { 28297a851edSJan Kara ext4_release_io_end(io_end); 28397a851edSJan Kara return; 28497a851edSJan Kara } 28597a851edSJan Kara ext4_add_complete_io(io_end); 28697a851edSJan Kara } 28797a851edSJan Kara } 28897a851edSJan Kara 28997a851edSJan Kara int ext4_put_io_end(ext4_io_end_t *io_end) 29097a851edSJan Kara { 29197a851edSJan Kara int err = 0; 29297a851edSJan Kara 29397a851edSJan Kara if (atomic_dec_and_test(&io_end->count)) { 29497a851edSJan Kara if (io_end->flag & EXT4_IO_END_UNWRITTEN) { 2956b523df4SJan Kara err = ext4_convert_unwritten_extents(io_end->handle, 2966b523df4SJan Kara io_end->inode, io_end->offset, 2976b523df4SJan Kara io_end->size); 2986b523df4SJan Kara io_end->handle = NULL; 29997a851edSJan Kara ext4_clear_io_unwritten_flag(io_end); 30097a851edSJan Kara } 30197a851edSJan Kara ext4_release_io_end(io_end); 30297a851edSJan Kara } 30397a851edSJan Kara return err; 30497a851edSJan Kara } 30597a851edSJan Kara 30697a851edSJan Kara ext4_io_end_t *ext4_get_io_end(ext4_io_end_t *io_end) 30797a851edSJan Kara { 30897a851edSJan Kara atomic_inc(&io_end->count); 30997a851edSJan Kara return io_end; 31097a851edSJan Kara } 31197a851edSJan Kara 312822dbba3SJan Kara /* BIO completion function for page writeback */ 313bd2d0210STheodore Ts'o static void ext4_end_bio(struct bio *bio, int error) 314bd2d0210STheodore Ts'o { 315bd2d0210STheodore Ts'o ext4_io_end_t *io_end = bio->bi_private; 3164f024f37SKent Overstreet sector_t bi_sector = bio->bi_iter.bi_sector; 317bd2d0210STheodore Ts'o 318bd2d0210STheodore Ts'o BUG_ON(!io_end); 319bd2d0210STheodore Ts'o bio->bi_end_io = NULL; 320bd2d0210STheodore Ts'o if (test_bit(BIO_UPTODATE, &bio->bi_flags)) 321bd2d0210STheodore Ts'o error = 0; 3220058f965SJan Kara 323f7ad6d2eSTheodore Ts'o if (error) { 324b0857d30SJan Kara struct inode *inode = io_end->inode; 325b0857d30SJan Kara 3269503c67cSMatthew Wilcox ext4_warning(inode->i_sb, "I/O error %d writing to inode %lu " 327f7ad6d2eSTheodore Ts'o "(offset %llu size %ld starting block %llu)", 3289503c67cSMatthew Wilcox error, inode->i_ino, 329f7ad6d2eSTheodore Ts'o (unsigned long long) io_end->offset, 330f7ad6d2eSTheodore Ts'o (long) io_end->size, 331f7ad6d2eSTheodore Ts'o (unsigned long long) 332d50bdd5aSCurt Wohlgemuth bi_sector >> (inode->i_blkbits - 9)); 3339503c67cSMatthew Wilcox mapping_set_error(inode->i_mapping, error); 334f7ad6d2eSTheodore Ts'o } 335822dbba3SJan Kara 336822dbba3SJan Kara if (io_end->flag & EXT4_IO_END_UNWRITTEN) { 337822dbba3SJan Kara /* 338822dbba3SJan Kara * Link bio into list hanging from io_end. We have to do it 339822dbba3SJan Kara * atomically as bio completions can be racing against each 340822dbba3SJan Kara * other. 341822dbba3SJan Kara */ 342822dbba3SJan Kara bio->bi_private = xchg(&io_end->bio, bio); 34397a851edSJan Kara ext4_put_io_end_defer(io_end); 344822dbba3SJan Kara } else { 345822dbba3SJan Kara /* 346822dbba3SJan Kara * Drop io_end reference early. Inode can get freed once 347822dbba3SJan Kara * we finish the bio. 348822dbba3SJan Kara */ 349822dbba3SJan Kara ext4_put_io_end_defer(io_end); 350822dbba3SJan Kara ext4_finish_bio(bio); 351822dbba3SJan Kara bio_put(bio); 352822dbba3SJan Kara } 353bd2d0210STheodore Ts'o } 354bd2d0210STheodore Ts'o 355bd2d0210STheodore Ts'o void ext4_io_submit(struct ext4_io_submit *io) 356bd2d0210STheodore Ts'o { 357bd2d0210STheodore Ts'o struct bio *bio = io->io_bio; 358bd2d0210STheodore Ts'o 359bd2d0210STheodore Ts'o if (bio) { 360*5a33911fSTejun Heo int io_op = io->io_wbc->sync_mode == WB_SYNC_ALL ? 361*5a33911fSTejun Heo WRITE_SYNC : WRITE; 362bd2d0210STheodore Ts'o bio_get(io->io_bio); 363*5a33911fSTejun Heo submit_bio(io_op, io->io_bio); 364bd2d0210STheodore Ts'o bio_put(io->io_bio); 365bd2d0210STheodore Ts'o } 3667dc57615SPeter Huewe io->io_bio = NULL; 36797a851edSJan Kara } 36897a851edSJan Kara 36997a851edSJan Kara void ext4_io_submit_init(struct ext4_io_submit *io, 37097a851edSJan Kara struct writeback_control *wbc) 37197a851edSJan Kara { 372*5a33911fSTejun Heo io->io_wbc = wbc; 37397a851edSJan Kara io->io_bio = NULL; 3747dc57615SPeter Huewe io->io_end = NULL; 375bd2d0210STheodore Ts'o } 376bd2d0210STheodore Ts'o 37797a851edSJan Kara static int io_submit_init_bio(struct ext4_io_submit *io, 378bd2d0210STheodore Ts'o struct buffer_head *bh) 379bd2d0210STheodore Ts'o { 380bd2d0210STheodore Ts'o int nvecs = bio_get_nr_vecs(bh->b_bdev); 381bd2d0210STheodore Ts'o struct bio *bio; 382bd2d0210STheodore Ts'o 383275d3ba6STheodore Ts'o bio = bio_alloc(GFP_NOIO, min(nvecs, BIO_MAX_PAGES)); 384a1d8d9a7STheodore Ts'o if (!bio) 385a1d8d9a7STheodore Ts'o return -ENOMEM; 3864f024f37SKent Overstreet bio->bi_iter.bi_sector = bh->b_blocknr * (bh->b_size >> 9); 387bd2d0210STheodore Ts'o bio->bi_bdev = bh->b_bdev; 388bd2d0210STheodore Ts'o bio->bi_end_io = ext4_end_bio; 38997a851edSJan Kara bio->bi_private = ext4_get_io_end(io->io_end); 390bd2d0210STheodore Ts'o io->io_bio = bio; 391bd2d0210STheodore Ts'o io->io_next_block = bh->b_blocknr; 392bd2d0210STheodore Ts'o return 0; 393bd2d0210STheodore Ts'o } 394bd2d0210STheodore Ts'o 395bd2d0210STheodore Ts'o static int io_submit_add_bh(struct ext4_io_submit *io, 396bd2d0210STheodore Ts'o struct inode *inode, 3972058f83aSMichael Halcrow struct page *page, 398bd2d0210STheodore Ts'o struct buffer_head *bh) 399bd2d0210STheodore Ts'o { 400bd2d0210STheodore Ts'o int ret; 401bd2d0210STheodore Ts'o 402bd2d0210STheodore Ts'o if (io->io_bio && bh->b_blocknr != io->io_next_block) { 403bd2d0210STheodore Ts'o submit_and_retry: 404bd2d0210STheodore Ts'o ext4_io_submit(io); 405bd2d0210STheodore Ts'o } 406bd2d0210STheodore Ts'o if (io->io_bio == NULL) { 40797a851edSJan Kara ret = io_submit_init_bio(io, bh); 408bd2d0210STheodore Ts'o if (ret) 409bd2d0210STheodore Ts'o return ret; 410bd2d0210STheodore Ts'o } 4112058f83aSMichael Halcrow ret = bio_add_page(io->io_bio, page, bh->b_size, bh_offset(bh)); 412a549984bSTheodore Ts'o if (ret != bh->b_size) 413a549984bSTheodore Ts'o goto submit_and_retry; 41497a851edSJan Kara io->io_next_block++; 415bd2d0210STheodore Ts'o return 0; 416bd2d0210STheodore Ts'o } 417bd2d0210STheodore Ts'o 418bd2d0210STheodore Ts'o int ext4_bio_write_page(struct ext4_io_submit *io, 419bd2d0210STheodore Ts'o struct page *page, 420bd2d0210STheodore Ts'o int len, 4211c8349a1SNamjae Jeon struct writeback_control *wbc, 4221c8349a1SNamjae Jeon bool keep_towrite) 423bd2d0210STheodore Ts'o { 4242058f83aSMichael Halcrow struct page *data_page = NULL; 425bd2d0210STheodore Ts'o struct inode *inode = page->mapping->host; 4260058f965SJan Kara unsigned block_start, blocksize; 427bd2d0210STheodore Ts'o struct buffer_head *bh, *head; 428bd2d0210STheodore Ts'o int ret = 0; 4290058f965SJan Kara int nr_submitted = 0; 430bd2d0210STheodore Ts'o 431bd2d0210STheodore Ts'o blocksize = 1 << inode->i_blkbits; 432bd2d0210STheodore Ts'o 433d50bdd5aSCurt Wohlgemuth BUG_ON(!PageLocked(page)); 434bd2d0210STheodore Ts'o BUG_ON(PageWriteback(page)); 435bd2d0210STheodore Ts'o 4361c8349a1SNamjae Jeon if (keep_towrite) 4371c8349a1SNamjae Jeon set_page_writeback_keepwrite(page); 4381c8349a1SNamjae Jeon else 439a54aa761STheodore Ts'o set_page_writeback(page); 440a54aa761STheodore Ts'o ClearPageError(page); 441bd2d0210STheodore Ts'o 4420058f965SJan Kara /* 443f8409abdSLinus Torvalds * Comments copied from block_write_full_page: 444eeece469SJan Kara * 445eeece469SJan Kara * The page straddles i_size. It must be zeroed out on each and every 446eeece469SJan Kara * writepage invocation because it may be mmapped. "A file is mapped 447eeece469SJan Kara * in multiples of the page size. For a file that is not a multiple of 448eeece469SJan Kara * the page size, the remaining memory is zeroed when mapped, and 449eeece469SJan Kara * writes to that region are not written out to the file." 450eeece469SJan Kara */ 451eeece469SJan Kara if (len < PAGE_CACHE_SIZE) 452eeece469SJan Kara zero_user_segment(page, len, PAGE_CACHE_SIZE); 453eeece469SJan Kara /* 4540058f965SJan Kara * In the first loop we prepare and mark buffers to submit. We have to 4550058f965SJan Kara * mark all buffers in the page before submitting so that 4560058f965SJan Kara * end_page_writeback() cannot be called from ext4_bio_end_io() when IO 4570058f965SJan Kara * on the first buffer finishes and we are still working on submitting 4580058f965SJan Kara * the second buffer. 4590058f965SJan Kara */ 4600058f965SJan Kara bh = head = page_buffers(page); 4610058f965SJan Kara do { 4620058f965SJan Kara block_start = bh_offset(bh); 463bd2d0210STheodore Ts'o if (block_start >= len) { 464bd2d0210STheodore Ts'o clear_buffer_dirty(bh); 465bd2d0210STheodore Ts'o set_buffer_uptodate(bh); 466bd2d0210STheodore Ts'o continue; 467bd2d0210STheodore Ts'o } 4688a850c3fSJan Kara if (!buffer_dirty(bh) || buffer_delay(bh) || 4698a850c3fSJan Kara !buffer_mapped(bh) || buffer_unwritten(bh)) { 4708a850c3fSJan Kara /* A hole? We can safely clear the dirty bit */ 4718a850c3fSJan Kara if (!buffer_mapped(bh)) 4728a850c3fSJan Kara clear_buffer_dirty(bh); 4738a850c3fSJan Kara if (io->io_bio) 4748a850c3fSJan Kara ext4_io_submit(io); 4758a850c3fSJan Kara continue; 4768a850c3fSJan Kara } 4770058f965SJan Kara if (buffer_new(bh)) { 4780058f965SJan Kara clear_buffer_new(bh); 4790058f965SJan Kara unmap_underlying_metadata(bh->b_bdev, bh->b_blocknr); 4800058f965SJan Kara } 4810058f965SJan Kara set_buffer_async_write(bh); 4820058f965SJan Kara } while ((bh = bh->b_this_page) != head); 4830058f965SJan Kara 4840058f965SJan Kara bh = head = page_buffers(page); 4852058f83aSMichael Halcrow 4862058f83aSMichael Halcrow if (ext4_encrypted_inode(inode) && S_ISREG(inode->i_mode)) { 4872058f83aSMichael Halcrow data_page = ext4_encrypt(inode, page); 4882058f83aSMichael Halcrow if (IS_ERR(data_page)) { 4892058f83aSMichael Halcrow ret = PTR_ERR(data_page); 4902058f83aSMichael Halcrow data_page = NULL; 4912058f83aSMichael Halcrow goto out; 4922058f83aSMichael Halcrow } 4932058f83aSMichael Halcrow } 4942058f83aSMichael Halcrow 4952058f83aSMichael Halcrow /* Now submit buffers to write */ 4960058f965SJan Kara do { 4970058f965SJan Kara if (!buffer_async_write(bh)) 4980058f965SJan Kara continue; 4992058f83aSMichael Halcrow ret = io_submit_add_bh(io, inode, 5002058f83aSMichael Halcrow data_page ? data_page : page, bh); 501bd2d0210STheodore Ts'o if (ret) { 502bd2d0210STheodore Ts'o /* 503bd2d0210STheodore Ts'o * We only get here on ENOMEM. Not much else 504bd2d0210STheodore Ts'o * we can do but mark the page as dirty, and 505bd2d0210STheodore Ts'o * better luck next time. 506bd2d0210STheodore Ts'o */ 507bd2d0210STheodore Ts'o break; 508bd2d0210STheodore Ts'o } 5090058f965SJan Kara nr_submitted++; 5101ae48a63SJan Kara clear_buffer_dirty(bh); 5110058f965SJan Kara } while ((bh = bh->b_this_page) != head); 5120058f965SJan Kara 5130058f965SJan Kara /* Error stopped previous loop? Clean up buffers... */ 5140058f965SJan Kara if (ret) { 5152058f83aSMichael Halcrow out: 5162058f83aSMichael Halcrow if (data_page) 5172058f83aSMichael Halcrow ext4_restore_control_page(data_page); 5182058f83aSMichael Halcrow printk_ratelimited(KERN_ERR "%s: ret = %d\n", __func__, ret); 5192058f83aSMichael Halcrow redirty_page_for_writepage(wbc, page); 5200058f965SJan Kara do { 5210058f965SJan Kara clear_buffer_async_write(bh); 5220058f965SJan Kara bh = bh->b_this_page; 5230058f965SJan Kara } while (bh != head); 524bd2d0210STheodore Ts'o } 525bd2d0210STheodore Ts'o unlock_page(page); 5260058f965SJan Kara /* Nothing submitted - we have to end page writeback */ 5270058f965SJan Kara if (!nr_submitted) 5280058f965SJan Kara end_page_writeback(page); 529bd2d0210STheodore Ts'o return ret; 530bd2d0210STheodore Ts'o } 531