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; 642c30c71bSKent Overstreet struct bio_vec *bvec; 65b0857d30SJan Kara 662c30c71bSKent Overstreet bio_for_each_segment_all(bvec, bio, i) { 67b0857d30SJan Kara struct page *page = bvec->bv_page; 682058f83aSMichael Halcrow #ifdef CONFIG_EXT4_FS_ENCRYPTION 692058f83aSMichael Halcrow struct page *data_page = NULL; 702058f83aSMichael Halcrow struct ext4_crypto_ctx *ctx = NULL; 712058f83aSMichael Halcrow #endif 72b0857d30SJan Kara struct buffer_head *bh, *head; 73b0857d30SJan Kara unsigned bio_start = bvec->bv_offset; 74b0857d30SJan Kara unsigned bio_end = bio_start + bvec->bv_len; 75b0857d30SJan Kara unsigned under_io = 0; 76b0857d30SJan Kara unsigned long flags; 77b0857d30SJan Kara 78b0857d30SJan Kara if (!page) 79b0857d30SJan Kara continue; 80b0857d30SJan Kara 812058f83aSMichael Halcrow #ifdef CONFIG_EXT4_FS_ENCRYPTION 822058f83aSMichael Halcrow if (!page->mapping) { 832058f83aSMichael Halcrow /* The bounce data pages are unmapped. */ 842058f83aSMichael Halcrow data_page = page; 852058f83aSMichael Halcrow ctx = (struct ext4_crypto_ctx *)page_private(data_page); 86614def70STheodore Ts'o page = ctx->w.control_page; 872058f83aSMichael Halcrow } 882058f83aSMichael Halcrow #endif 892058f83aSMichael Halcrow 90*4246a0b6SChristoph Hellwig if (bio->bi_error) { 91b0857d30SJan Kara SetPageError(page); 92b0857d30SJan Kara set_bit(AS_EIO, &page->mapping->flags); 93b0857d30SJan Kara } 94b0857d30SJan Kara bh = head = page_buffers(page); 95b0857d30SJan Kara /* 96b0857d30SJan Kara * We check all buffers in the page under BH_Uptodate_Lock 97b0857d30SJan Kara * to avoid races with other end io clearing async_write flags 98b0857d30SJan Kara */ 99b0857d30SJan Kara local_irq_save(flags); 100b0857d30SJan Kara bit_spin_lock(BH_Uptodate_Lock, &head->b_state); 101b0857d30SJan Kara do { 102b0857d30SJan Kara if (bh_offset(bh) < bio_start || 103b0857d30SJan Kara bh_offset(bh) + bh->b_size > bio_end) { 104b0857d30SJan Kara if (buffer_async_write(bh)) 105b0857d30SJan Kara under_io++; 106b0857d30SJan Kara continue; 107b0857d30SJan Kara } 108b0857d30SJan Kara clear_buffer_async_write(bh); 109*4246a0b6SChristoph Hellwig if (bio->bi_error) 110b0857d30SJan Kara buffer_io_error(bh); 111b0857d30SJan Kara } while ((bh = bh->b_this_page) != head); 112b0857d30SJan Kara bit_spin_unlock(BH_Uptodate_Lock, &head->b_state); 113b0857d30SJan Kara local_irq_restore(flags); 1142058f83aSMichael Halcrow if (!under_io) { 1152058f83aSMichael Halcrow #ifdef CONFIG_EXT4_FS_ENCRYPTION 1162058f83aSMichael Halcrow if (ctx) 1172058f83aSMichael Halcrow ext4_restore_control_page(data_page); 1182058f83aSMichael Halcrow #endif 119b0857d30SJan Kara end_page_writeback(page); 120b0857d30SJan Kara } 121b0857d30SJan Kara } 1222058f83aSMichael Halcrow } 123b0857d30SJan Kara 12497a851edSJan Kara static void ext4_release_io_end(ext4_io_end_t *io_end) 125bd2d0210STheodore Ts'o { 126b0857d30SJan Kara struct bio *bio, *next_bio; 127b0857d30SJan Kara 12897a851edSJan Kara BUG_ON(!list_empty(&io_end->list)); 12997a851edSJan Kara BUG_ON(io_end->flag & EXT4_IO_END_UNWRITTEN); 1306b523df4SJan Kara WARN_ON(io_end->handle); 131bd2d0210STheodore Ts'o 13297a851edSJan Kara if (atomic_dec_and_test(&EXT4_I(io_end->inode)->i_ioend_count)) 13397a851edSJan Kara wake_up_all(ext4_ioend_wq(io_end->inode)); 134b0857d30SJan Kara 135b0857d30SJan Kara for (bio = io_end->bio; bio; bio = next_bio) { 136b0857d30SJan Kara next_bio = bio->bi_private; 137b0857d30SJan Kara ext4_finish_bio(bio); 138b0857d30SJan Kara bio_put(bio); 139b0857d30SJan Kara } 14097a851edSJan Kara kmem_cache_free(io_end_cachep, io_end); 14197a851edSJan Kara } 14297a851edSJan Kara 14397a851edSJan Kara static void ext4_clear_io_unwritten_flag(ext4_io_end_t *io_end) 14497a851edSJan Kara { 14597a851edSJan Kara struct inode *inode = io_end->inode; 14697a851edSJan Kara 14797a851edSJan Kara io_end->flag &= ~EXT4_IO_END_UNWRITTEN; 14897a851edSJan Kara /* Wake up anyone waiting on unwritten extent conversion */ 14997a851edSJan Kara if (atomic_dec_and_test(&EXT4_I(inode)->i_unwritten)) 15097a851edSJan Kara wake_up_all(ext4_ioend_wq(inode)); 151bd2d0210STheodore Ts'o } 152bd2d0210STheodore Ts'o 153a115f749SJan Kara /* 154a115f749SJan Kara * Check a range of space and convert unwritten extents to written. Note that 155a115f749SJan Kara * we are protected from truncate touching same part of extent tree by the 156a115f749SJan Kara * fact that truncate code waits for all DIO to finish (thus exclusion from 157a115f749SJan Kara * direct IO is achieved) and also waits for PageWriteback bits. Thus we 158a115f749SJan Kara * cannot get to ext4_ext_truncate() before all IOs overlapping that range are 159a115f749SJan Kara * completed (happens from ext4_free_ioend()). 160a115f749SJan Kara */ 16128a535f9SDmitry Monakhov static int ext4_end_io(ext4_io_end_t *io) 162bd2d0210STheodore Ts'o { 163bd2d0210STheodore Ts'o struct inode *inode = io->inode; 164bd2d0210STheodore Ts'o loff_t offset = io->offset; 165bd2d0210STheodore Ts'o ssize_t size = io->size; 1666b523df4SJan Kara handle_t *handle = io->handle; 167bd2d0210STheodore Ts'o int ret = 0; 168bd2d0210STheodore Ts'o 169bd2d0210STheodore Ts'o ext4_debug("ext4_end_io_nolock: io 0x%p from inode %lu,list->next 0x%p," 170bd2d0210STheodore Ts'o "list->prev 0x%p\n", 171bd2d0210STheodore Ts'o io, inode->i_ino, io->list.next, io->list.prev); 172bd2d0210STheodore Ts'o 1736b523df4SJan Kara io->handle = NULL; /* Following call will use up the handle */ 1746b523df4SJan Kara ret = ext4_convert_unwritten_extents(handle, inode, offset, size); 175bd2d0210STheodore Ts'o if (ret < 0) { 176b82e384cSTheodore Ts'o ext4_msg(inode->i_sb, KERN_EMERG, 177b82e384cSTheodore Ts'o "failed to convert unwritten extents to written " 178b82e384cSTheodore Ts'o "extents -- potential data loss! " 179b82e384cSTheodore Ts'o "(inode %lu, offset %llu, size %zd, error %d)", 180b82e384cSTheodore Ts'o inode->i_ino, offset, size, ret); 181bd2d0210STheodore Ts'o } 18297a851edSJan Kara ext4_clear_io_unwritten_flag(io); 18397a851edSJan Kara ext4_release_io_end(io); 184bd2d0210STheodore Ts'o return ret; 185bd2d0210STheodore Ts'o } 186bd2d0210STheodore Ts'o 1872e8fa54eSJan Kara static void dump_completed_IO(struct inode *inode, struct list_head *head) 18828a535f9SDmitry Monakhov { 18928a535f9SDmitry Monakhov #ifdef EXT4FS_DEBUG 19028a535f9SDmitry Monakhov struct list_head *cur, *before, *after; 19128a535f9SDmitry Monakhov ext4_io_end_t *io, *io0, *io1; 19228a535f9SDmitry Monakhov 1932e8fa54eSJan Kara if (list_empty(head)) 19428a535f9SDmitry Monakhov return; 19528a535f9SDmitry Monakhov 1962e8fa54eSJan Kara ext4_debug("Dump inode %lu completed io list\n", inode->i_ino); 1972e8fa54eSJan Kara list_for_each_entry(io, head, list) { 19828a535f9SDmitry Monakhov cur = &io->list; 19928a535f9SDmitry Monakhov before = cur->prev; 20028a535f9SDmitry Monakhov io0 = container_of(before, ext4_io_end_t, list); 20128a535f9SDmitry Monakhov after = cur->next; 20228a535f9SDmitry Monakhov io1 = container_of(after, ext4_io_end_t, list); 20328a535f9SDmitry Monakhov 20428a535f9SDmitry Monakhov ext4_debug("io 0x%p from inode %lu,prev 0x%p,next 0x%p\n", 20528a535f9SDmitry Monakhov io, inode->i_ino, io0, io1); 20628a535f9SDmitry Monakhov } 20728a535f9SDmitry Monakhov #endif 20828a535f9SDmitry Monakhov } 20928a535f9SDmitry Monakhov 21028a535f9SDmitry Monakhov /* Add the io_end to per-inode completed end_io list. */ 21197a851edSJan Kara static void ext4_add_complete_io(ext4_io_end_t *io_end) 21228a535f9SDmitry Monakhov { 21328a535f9SDmitry Monakhov struct ext4_inode_info *ei = EXT4_I(io_end->inode); 21478371a45SJan Kara struct ext4_sb_info *sbi = EXT4_SB(io_end->inode->i_sb); 21528a535f9SDmitry Monakhov struct workqueue_struct *wq; 21628a535f9SDmitry Monakhov unsigned long flags; 21728a535f9SDmitry Monakhov 2187b7a8665SChristoph Hellwig /* Only reserved conversions from writeback should enter here */ 2197b7a8665SChristoph Hellwig WARN_ON(!(io_end->flag & EXT4_IO_END_UNWRITTEN)); 22078371a45SJan Kara WARN_ON(!io_end->handle && sbi->s_journal); 22128a535f9SDmitry Monakhov spin_lock_irqsave(&ei->i_completed_io_lock, flags); 22278371a45SJan Kara wq = sbi->rsv_conversion_wq; 2232e8fa54eSJan Kara if (list_empty(&ei->i_rsv_conversion_list)) 2242e8fa54eSJan Kara queue_work(wq, &ei->i_rsv_conversion_work); 2252e8fa54eSJan Kara list_add_tail(&io_end->list, &ei->i_rsv_conversion_list); 22628a535f9SDmitry Monakhov spin_unlock_irqrestore(&ei->i_completed_io_lock, flags); 22728a535f9SDmitry Monakhov } 22828a535f9SDmitry Monakhov 2292e8fa54eSJan Kara static int ext4_do_flush_completed_IO(struct inode *inode, 2302e8fa54eSJan Kara struct list_head *head) 23128a535f9SDmitry Monakhov { 23228a535f9SDmitry Monakhov ext4_io_end_t *io; 233002bd7faSJan Kara struct list_head unwritten; 23428a535f9SDmitry Monakhov unsigned long flags; 23528a535f9SDmitry Monakhov struct ext4_inode_info *ei = EXT4_I(inode); 23628a535f9SDmitry Monakhov int err, ret = 0; 23728a535f9SDmitry Monakhov 23828a535f9SDmitry Monakhov spin_lock_irqsave(&ei->i_completed_io_lock, flags); 2392e8fa54eSJan Kara dump_completed_IO(inode, head); 2402e8fa54eSJan Kara list_replace_init(head, &unwritten); 24128a535f9SDmitry Monakhov spin_unlock_irqrestore(&ei->i_completed_io_lock, flags); 24228a535f9SDmitry Monakhov 24328a535f9SDmitry Monakhov while (!list_empty(&unwritten)) { 24428a535f9SDmitry Monakhov io = list_entry(unwritten.next, ext4_io_end_t, list); 24528a535f9SDmitry Monakhov BUG_ON(!(io->flag & EXT4_IO_END_UNWRITTEN)); 24628a535f9SDmitry Monakhov list_del_init(&io->list); 24728a535f9SDmitry Monakhov 24828a535f9SDmitry Monakhov err = ext4_end_io(io); 24928a535f9SDmitry Monakhov if (unlikely(!ret && err)) 25028a535f9SDmitry Monakhov ret = err; 25128a535f9SDmitry Monakhov } 25228a535f9SDmitry Monakhov return ret; 25328a535f9SDmitry Monakhov } 25428a535f9SDmitry Monakhov 255bd2d0210STheodore Ts'o /* 2562e8fa54eSJan Kara * work on completed IO, to convert unwritten extents to extents 257bd2d0210STheodore Ts'o */ 2582e8fa54eSJan Kara void ext4_end_io_rsv_work(struct work_struct *work) 259bd2d0210STheodore Ts'o { 26084c17543SJan Kara struct ext4_inode_info *ei = container_of(work, struct ext4_inode_info, 2612e8fa54eSJan Kara i_rsv_conversion_work); 2622e8fa54eSJan Kara ext4_do_flush_completed_IO(&ei->vfs_inode, &ei->i_rsv_conversion_list); 2632e8fa54eSJan Kara } 2642e8fa54eSJan Kara 265bd2d0210STheodore Ts'o ext4_io_end_t *ext4_init_io_end(struct inode *inode, gfp_t flags) 266bd2d0210STheodore Ts'o { 267b17b35ecSJesper Juhl ext4_io_end_t *io = kmem_cache_zalloc(io_end_cachep, flags); 268bd2d0210STheodore Ts'o if (io) { 269f7ad6d2eSTheodore Ts'o atomic_inc(&EXT4_I(inode)->i_ioend_count); 270f7ad6d2eSTheodore Ts'o io->inode = inode; 271bd2d0210STheodore Ts'o INIT_LIST_HEAD(&io->list); 27297a851edSJan Kara atomic_set(&io->count, 1); 273bd2d0210STheodore Ts'o } 274bd2d0210STheodore Ts'o return io; 275bd2d0210STheodore Ts'o } 276bd2d0210STheodore Ts'o 27797a851edSJan Kara void ext4_put_io_end_defer(ext4_io_end_t *io_end) 27897a851edSJan Kara { 27997a851edSJan Kara if (atomic_dec_and_test(&io_end->count)) { 28097a851edSJan Kara if (!(io_end->flag & EXT4_IO_END_UNWRITTEN) || !io_end->size) { 28197a851edSJan Kara ext4_release_io_end(io_end); 28297a851edSJan Kara return; 28397a851edSJan Kara } 28497a851edSJan Kara ext4_add_complete_io(io_end); 28597a851edSJan Kara } 28697a851edSJan Kara } 28797a851edSJan Kara 28897a851edSJan Kara int ext4_put_io_end(ext4_io_end_t *io_end) 28997a851edSJan Kara { 29097a851edSJan Kara int err = 0; 29197a851edSJan Kara 29297a851edSJan Kara if (atomic_dec_and_test(&io_end->count)) { 29397a851edSJan Kara if (io_end->flag & EXT4_IO_END_UNWRITTEN) { 2946b523df4SJan Kara err = ext4_convert_unwritten_extents(io_end->handle, 2956b523df4SJan Kara io_end->inode, io_end->offset, 2966b523df4SJan Kara io_end->size); 2976b523df4SJan Kara io_end->handle = NULL; 29897a851edSJan Kara ext4_clear_io_unwritten_flag(io_end); 29997a851edSJan Kara } 30097a851edSJan Kara ext4_release_io_end(io_end); 30197a851edSJan Kara } 30297a851edSJan Kara return err; 30397a851edSJan Kara } 30497a851edSJan Kara 30597a851edSJan Kara ext4_io_end_t *ext4_get_io_end(ext4_io_end_t *io_end) 30697a851edSJan Kara { 30797a851edSJan Kara atomic_inc(&io_end->count); 30897a851edSJan Kara return io_end; 30997a851edSJan Kara } 31097a851edSJan Kara 311822dbba3SJan Kara /* BIO completion function for page writeback */ 312*4246a0b6SChristoph Hellwig static void ext4_end_bio(struct bio *bio) 313bd2d0210STheodore Ts'o { 314bd2d0210STheodore Ts'o ext4_io_end_t *io_end = bio->bi_private; 3154f024f37SKent Overstreet sector_t bi_sector = bio->bi_iter.bi_sector; 316bd2d0210STheodore Ts'o 317bd2d0210STheodore Ts'o BUG_ON(!io_end); 318bd2d0210STheodore Ts'o bio->bi_end_io = NULL; 3190058f965SJan Kara 320*4246a0b6SChristoph Hellwig if (bio->bi_error) { 321b0857d30SJan Kara struct inode *inode = io_end->inode; 322b0857d30SJan Kara 3239503c67cSMatthew Wilcox ext4_warning(inode->i_sb, "I/O error %d writing to inode %lu " 324f7ad6d2eSTheodore Ts'o "(offset %llu size %ld starting block %llu)", 325*4246a0b6SChristoph Hellwig bio->bi_error, inode->i_ino, 326f7ad6d2eSTheodore Ts'o (unsigned long long) io_end->offset, 327f7ad6d2eSTheodore Ts'o (long) io_end->size, 328f7ad6d2eSTheodore Ts'o (unsigned long long) 329d50bdd5aSCurt Wohlgemuth bi_sector >> (inode->i_blkbits - 9)); 330*4246a0b6SChristoph Hellwig mapping_set_error(inode->i_mapping, bio->bi_error); 331f7ad6d2eSTheodore Ts'o } 332822dbba3SJan Kara 333822dbba3SJan Kara if (io_end->flag & EXT4_IO_END_UNWRITTEN) { 334822dbba3SJan Kara /* 335822dbba3SJan Kara * Link bio into list hanging from io_end. We have to do it 336822dbba3SJan Kara * atomically as bio completions can be racing against each 337822dbba3SJan Kara * other. 338822dbba3SJan Kara */ 339822dbba3SJan Kara bio->bi_private = xchg(&io_end->bio, bio); 34097a851edSJan Kara ext4_put_io_end_defer(io_end); 341822dbba3SJan Kara } else { 342822dbba3SJan Kara /* 343822dbba3SJan Kara * Drop io_end reference early. Inode can get freed once 344822dbba3SJan Kara * we finish the bio. 345822dbba3SJan Kara */ 346822dbba3SJan Kara ext4_put_io_end_defer(io_end); 347822dbba3SJan Kara ext4_finish_bio(bio); 348822dbba3SJan Kara bio_put(bio); 349822dbba3SJan Kara } 350bd2d0210STheodore Ts'o } 351bd2d0210STheodore Ts'o 352bd2d0210STheodore Ts'o void ext4_io_submit(struct ext4_io_submit *io) 353bd2d0210STheodore Ts'o { 354bd2d0210STheodore Ts'o struct bio *bio = io->io_bio; 355bd2d0210STheodore Ts'o 356bd2d0210STheodore Ts'o if (bio) { 357bd2d0210STheodore Ts'o bio_get(io->io_bio); 358bd2d0210STheodore Ts'o submit_bio(io->io_op, io->io_bio); 359bd2d0210STheodore Ts'o bio_put(io->io_bio); 360bd2d0210STheodore Ts'o } 3617dc57615SPeter Huewe io->io_bio = NULL; 36297a851edSJan Kara } 36397a851edSJan Kara 36497a851edSJan Kara void ext4_io_submit_init(struct ext4_io_submit *io, 36597a851edSJan Kara struct writeback_control *wbc) 36697a851edSJan Kara { 36797a851edSJan Kara io->io_op = (wbc->sync_mode == WB_SYNC_ALL ? WRITE_SYNC : WRITE); 36897a851edSJan Kara io->io_bio = NULL; 3697dc57615SPeter Huewe io->io_end = NULL; 370bd2d0210STheodore Ts'o } 371bd2d0210STheodore Ts'o 37297a851edSJan Kara static int io_submit_init_bio(struct ext4_io_submit *io, 373bd2d0210STheodore Ts'o struct buffer_head *bh) 374bd2d0210STheodore Ts'o { 375bd2d0210STheodore Ts'o int nvecs = bio_get_nr_vecs(bh->b_bdev); 376bd2d0210STheodore Ts'o struct bio *bio; 377bd2d0210STheodore Ts'o 378275d3ba6STheodore Ts'o bio = bio_alloc(GFP_NOIO, min(nvecs, BIO_MAX_PAGES)); 379a1d8d9a7STheodore Ts'o if (!bio) 380a1d8d9a7STheodore Ts'o return -ENOMEM; 3814f024f37SKent Overstreet bio->bi_iter.bi_sector = bh->b_blocknr * (bh->b_size >> 9); 382bd2d0210STheodore Ts'o bio->bi_bdev = bh->b_bdev; 383bd2d0210STheodore Ts'o bio->bi_end_io = ext4_end_bio; 38497a851edSJan Kara bio->bi_private = ext4_get_io_end(io->io_end); 385bd2d0210STheodore Ts'o io->io_bio = bio; 386bd2d0210STheodore Ts'o io->io_next_block = bh->b_blocknr; 387bd2d0210STheodore Ts'o return 0; 388bd2d0210STheodore Ts'o } 389bd2d0210STheodore Ts'o 390bd2d0210STheodore Ts'o static int io_submit_add_bh(struct ext4_io_submit *io, 391bd2d0210STheodore Ts'o struct inode *inode, 3922058f83aSMichael Halcrow struct page *page, 393bd2d0210STheodore Ts'o struct buffer_head *bh) 394bd2d0210STheodore Ts'o { 395bd2d0210STheodore Ts'o int ret; 396bd2d0210STheodore Ts'o 397bd2d0210STheodore Ts'o if (io->io_bio && bh->b_blocknr != io->io_next_block) { 398bd2d0210STheodore Ts'o submit_and_retry: 399bd2d0210STheodore Ts'o ext4_io_submit(io); 400bd2d0210STheodore Ts'o } 401bd2d0210STheodore Ts'o if (io->io_bio == NULL) { 40297a851edSJan Kara ret = io_submit_init_bio(io, bh); 403bd2d0210STheodore Ts'o if (ret) 404bd2d0210STheodore Ts'o return ret; 405bd2d0210STheodore Ts'o } 4062058f83aSMichael Halcrow ret = bio_add_page(io->io_bio, page, bh->b_size, bh_offset(bh)); 407a549984bSTheodore Ts'o if (ret != bh->b_size) 408a549984bSTheodore Ts'o goto submit_and_retry; 40997a851edSJan Kara io->io_next_block++; 410bd2d0210STheodore Ts'o return 0; 411bd2d0210STheodore Ts'o } 412bd2d0210STheodore Ts'o 413bd2d0210STheodore Ts'o int ext4_bio_write_page(struct ext4_io_submit *io, 414bd2d0210STheodore Ts'o struct page *page, 415bd2d0210STheodore Ts'o int len, 4161c8349a1SNamjae Jeon struct writeback_control *wbc, 4171c8349a1SNamjae Jeon bool keep_towrite) 418bd2d0210STheodore Ts'o { 4192058f83aSMichael Halcrow struct page *data_page = NULL; 420bd2d0210STheodore Ts'o struct inode *inode = page->mapping->host; 4210058f965SJan Kara unsigned block_start, blocksize; 422bd2d0210STheodore Ts'o struct buffer_head *bh, *head; 423bd2d0210STheodore Ts'o int ret = 0; 4240058f965SJan Kara int nr_submitted = 0; 425bd2d0210STheodore Ts'o 426bd2d0210STheodore Ts'o blocksize = 1 << inode->i_blkbits; 427bd2d0210STheodore Ts'o 428d50bdd5aSCurt Wohlgemuth BUG_ON(!PageLocked(page)); 429bd2d0210STheodore Ts'o BUG_ON(PageWriteback(page)); 430bd2d0210STheodore Ts'o 4311c8349a1SNamjae Jeon if (keep_towrite) 4321c8349a1SNamjae Jeon set_page_writeback_keepwrite(page); 4331c8349a1SNamjae Jeon else 434a54aa761STheodore Ts'o set_page_writeback(page); 435a54aa761STheodore Ts'o ClearPageError(page); 436bd2d0210STheodore Ts'o 4370058f965SJan Kara /* 438f8409abdSLinus Torvalds * Comments copied from block_write_full_page: 439eeece469SJan Kara * 440eeece469SJan Kara * The page straddles i_size. It must be zeroed out on each and every 441eeece469SJan Kara * writepage invocation because it may be mmapped. "A file is mapped 442eeece469SJan Kara * in multiples of the page size. For a file that is not a multiple of 443eeece469SJan Kara * the page size, the remaining memory is zeroed when mapped, and 444eeece469SJan Kara * writes to that region are not written out to the file." 445eeece469SJan Kara */ 446eeece469SJan Kara if (len < PAGE_CACHE_SIZE) 447eeece469SJan Kara zero_user_segment(page, len, PAGE_CACHE_SIZE); 448eeece469SJan Kara /* 4490058f965SJan Kara * In the first loop we prepare and mark buffers to submit. We have to 4500058f965SJan Kara * mark all buffers in the page before submitting so that 4510058f965SJan Kara * end_page_writeback() cannot be called from ext4_bio_end_io() when IO 4520058f965SJan Kara * on the first buffer finishes and we are still working on submitting 4530058f965SJan Kara * the second buffer. 4540058f965SJan Kara */ 4550058f965SJan Kara bh = head = page_buffers(page); 4560058f965SJan Kara do { 4570058f965SJan Kara block_start = bh_offset(bh); 458bd2d0210STheodore Ts'o if (block_start >= len) { 459bd2d0210STheodore Ts'o clear_buffer_dirty(bh); 460bd2d0210STheodore Ts'o set_buffer_uptodate(bh); 461bd2d0210STheodore Ts'o continue; 462bd2d0210STheodore Ts'o } 4638a850c3fSJan Kara if (!buffer_dirty(bh) || buffer_delay(bh) || 4648a850c3fSJan Kara !buffer_mapped(bh) || buffer_unwritten(bh)) { 4658a850c3fSJan Kara /* A hole? We can safely clear the dirty bit */ 4668a850c3fSJan Kara if (!buffer_mapped(bh)) 4678a850c3fSJan Kara clear_buffer_dirty(bh); 4688a850c3fSJan Kara if (io->io_bio) 4698a850c3fSJan Kara ext4_io_submit(io); 4708a850c3fSJan Kara continue; 4718a850c3fSJan Kara } 4720058f965SJan Kara if (buffer_new(bh)) { 4730058f965SJan Kara clear_buffer_new(bh); 4740058f965SJan Kara unmap_underlying_metadata(bh->b_bdev, bh->b_blocknr); 4750058f965SJan Kara } 4760058f965SJan Kara set_buffer_async_write(bh); 4770058f965SJan Kara } while ((bh = bh->b_this_page) != head); 4780058f965SJan Kara 4790058f965SJan Kara bh = head = page_buffers(page); 4802058f83aSMichael Halcrow 4812058f83aSMichael Halcrow if (ext4_encrypted_inode(inode) && S_ISREG(inode->i_mode)) { 4822058f83aSMichael Halcrow data_page = ext4_encrypt(inode, page); 4832058f83aSMichael Halcrow if (IS_ERR(data_page)) { 4842058f83aSMichael Halcrow ret = PTR_ERR(data_page); 4852058f83aSMichael Halcrow data_page = NULL; 4862058f83aSMichael Halcrow goto out; 4872058f83aSMichael Halcrow } 4882058f83aSMichael Halcrow } 4892058f83aSMichael Halcrow 4902058f83aSMichael Halcrow /* Now submit buffers to write */ 4910058f965SJan Kara do { 4920058f965SJan Kara if (!buffer_async_write(bh)) 4930058f965SJan Kara continue; 4942058f83aSMichael Halcrow ret = io_submit_add_bh(io, inode, 4952058f83aSMichael Halcrow data_page ? data_page : page, bh); 496bd2d0210STheodore Ts'o if (ret) { 497bd2d0210STheodore Ts'o /* 498bd2d0210STheodore Ts'o * We only get here on ENOMEM. Not much else 499bd2d0210STheodore Ts'o * we can do but mark the page as dirty, and 500bd2d0210STheodore Ts'o * better luck next time. 501bd2d0210STheodore Ts'o */ 502bd2d0210STheodore Ts'o break; 503bd2d0210STheodore Ts'o } 5040058f965SJan Kara nr_submitted++; 5051ae48a63SJan Kara clear_buffer_dirty(bh); 5060058f965SJan Kara } while ((bh = bh->b_this_page) != head); 5070058f965SJan Kara 5080058f965SJan Kara /* Error stopped previous loop? Clean up buffers... */ 5090058f965SJan Kara if (ret) { 5102058f83aSMichael Halcrow out: 5112058f83aSMichael Halcrow if (data_page) 5122058f83aSMichael Halcrow ext4_restore_control_page(data_page); 5132058f83aSMichael Halcrow printk_ratelimited(KERN_ERR "%s: ret = %d\n", __func__, ret); 5142058f83aSMichael Halcrow redirty_page_for_writepage(wbc, page); 5150058f965SJan Kara do { 5160058f965SJan Kara clear_buffer_async_write(bh); 5170058f965SJan Kara bh = bh->b_this_page; 5180058f965SJan Kara } while (bh != head); 519bd2d0210STheodore Ts'o } 520bd2d0210STheodore Ts'o unlock_page(page); 5210058f965SJan Kara /* Nothing submitted - we have to end page writeback */ 5220058f965SJan Kara if (!nr_submitted) 5230058f965SJan Kara end_page_writeback(page); 524bd2d0210STheodore Ts'o return ret; 525bd2d0210STheodore Ts'o } 526