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/jbd2.h> 12bd2d0210STheodore Ts'o #include <linux/highuid.h> 13bd2d0210STheodore Ts'o #include <linux/pagemap.h> 14bd2d0210STheodore Ts'o #include <linux/quotaops.h> 15bd2d0210STheodore Ts'o #include <linux/string.h> 16bd2d0210STheodore Ts'o #include <linux/buffer_head.h> 17bd2d0210STheodore Ts'o #include <linux/writeback.h> 18bd2d0210STheodore Ts'o #include <linux/pagevec.h> 19bd2d0210STheodore Ts'o #include <linux/mpage.h> 20bd2d0210STheodore Ts'o #include <linux/namei.h> 21bd2d0210STheodore Ts'o #include <linux/uio.h> 22bd2d0210STheodore Ts'o #include <linux/bio.h> 23bd2d0210STheodore Ts'o #include <linux/workqueue.h> 24bd2d0210STheodore Ts'o #include <linux/kernel.h> 25bd2d0210STheodore Ts'o #include <linux/slab.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 #include "ext4_extents.h" 31bd2d0210STheodore Ts'o 32bd2d0210STheodore Ts'o static struct kmem_cache *io_page_cachep, *io_end_cachep; 33bd2d0210STheodore Ts'o 345dabfc78STheodore Ts'o int __init ext4_init_pageio(void) 35bd2d0210STheodore Ts'o { 36bd2d0210STheodore Ts'o io_page_cachep = KMEM_CACHE(ext4_io_page, SLAB_RECLAIM_ACCOUNT); 37bd2d0210STheodore Ts'o if (io_page_cachep == NULL) 38bd2d0210STheodore Ts'o return -ENOMEM; 39bd2d0210STheodore Ts'o io_end_cachep = KMEM_CACHE(ext4_io_end, SLAB_RECLAIM_ACCOUNT); 4013195184SDan Carpenter if (io_end_cachep == NULL) { 41bd2d0210STheodore Ts'o kmem_cache_destroy(io_page_cachep); 42bd2d0210STheodore Ts'o return -ENOMEM; 43bd2d0210STheodore Ts'o } 44bd2d0210STheodore Ts'o return 0; 45bd2d0210STheodore Ts'o } 46bd2d0210STheodore Ts'o 475dabfc78STheodore Ts'o void ext4_exit_pageio(void) 48bd2d0210STheodore Ts'o { 49bd2d0210STheodore Ts'o kmem_cache_destroy(io_end_cachep); 50bd2d0210STheodore Ts'o kmem_cache_destroy(io_page_cachep); 51bd2d0210STheodore Ts'o } 52bd2d0210STheodore Ts'o 53f7ad6d2eSTheodore Ts'o void ext4_ioend_wait(struct inode *inode) 54f7ad6d2eSTheodore Ts'o { 55e9e3bcecSEric Sandeen wait_queue_head_t *wq = ext4_ioend_wq(inode); 56f7ad6d2eSTheodore Ts'o 57f7ad6d2eSTheodore Ts'o wait_event(*wq, (atomic_read(&EXT4_I(inode)->i_ioend_count) == 0)); 58f7ad6d2eSTheodore Ts'o } 59f7ad6d2eSTheodore Ts'o 6083668e71STheodore Ts'o static void put_io_page(struct ext4_io_page *io_page) 6183668e71STheodore Ts'o { 6283668e71STheodore Ts'o if (atomic_dec_and_test(&io_page->p_count)) { 636268b325SLinus Torvalds end_page_writeback(io_page->p_page); 6483668e71STheodore Ts'o put_page(io_page->p_page); 6583668e71STheodore Ts'o kmem_cache_free(io_page_cachep, io_page); 6683668e71STheodore Ts'o } 6783668e71STheodore Ts'o } 6883668e71STheodore Ts'o 69bd2d0210STheodore Ts'o void ext4_free_io_end(ext4_io_end_t *io) 70bd2d0210STheodore Ts'o { 71bd2d0210STheodore Ts'o int i; 72bd2d0210STheodore Ts'o 73bd2d0210STheodore Ts'o BUG_ON(!io); 74*28a535f9SDmitry Monakhov BUG_ON(!list_empty(&io->list)); 7582e54229SDmitry Monakhov BUG_ON(io->flag & EXT4_IO_END_UNWRITTEN); 7682e54229SDmitry Monakhov 77bd2d0210STheodore Ts'o if (io->page) 78bd2d0210STheodore Ts'o put_page(io->page); 7983668e71STheodore Ts'o for (i = 0; i < io->num_io_pages; i++) 8083668e71STheodore Ts'o put_io_page(io->pages[i]); 81bd2d0210STheodore Ts'o io->num_io_pages = 0; 824e298021STheodore Ts'o if (atomic_dec_and_test(&EXT4_I(io->inode)->i_ioend_count)) 834e298021STheodore Ts'o wake_up_all(ext4_ioend_wq(io->inode)); 84bd2d0210STheodore Ts'o kmem_cache_free(io_end_cachep, io); 85bd2d0210STheodore Ts'o } 86bd2d0210STheodore Ts'o 87*28a535f9SDmitry Monakhov /* check a range of space and convert unwritten extents to written. */ 88*28a535f9SDmitry Monakhov static int ext4_end_io(ext4_io_end_t *io) 89bd2d0210STheodore Ts'o { 90bd2d0210STheodore Ts'o struct inode *inode = io->inode; 91bd2d0210STheodore Ts'o loff_t offset = io->offset; 92bd2d0210STheodore Ts'o ssize_t size = io->size; 93bd2d0210STheodore Ts'o int ret = 0; 94bd2d0210STheodore Ts'o 95bd2d0210STheodore Ts'o ext4_debug("ext4_end_io_nolock: io 0x%p from inode %lu,list->next 0x%p," 96bd2d0210STheodore Ts'o "list->prev 0x%p\n", 97bd2d0210STheodore Ts'o io, inode->i_ino, io->list.next, io->list.prev); 98bd2d0210STheodore Ts'o 99bd2d0210STheodore Ts'o ret = ext4_convert_unwritten_extents(inode, offset, size); 100bd2d0210STheodore Ts'o if (ret < 0) { 101b82e384cSTheodore Ts'o ext4_msg(inode->i_sb, KERN_EMERG, 102b82e384cSTheodore Ts'o "failed to convert unwritten extents to written " 103b82e384cSTheodore Ts'o "extents -- potential data loss! " 104b82e384cSTheodore Ts'o "(inode %lu, offset %llu, size %zd, error %d)", 105b82e384cSTheodore Ts'o inode->i_ino, offset, size, ret); 106bd2d0210STheodore Ts'o } 107bd2d0210STheodore Ts'o if (io->iocb) 108bd2d0210STheodore Ts'o aio_complete(io->iocb, io->result, 0); 109b82e384cSTheodore Ts'o 110266991b1SJeff Moyer if (io->flag & EXT4_IO_END_DIRECT) 111266991b1SJeff Moyer inode_dio_done(inode); 112e9e3bcecSEric Sandeen /* Wake up anyone waiting on unwritten extent conversion */ 113e27f41e1SDmitry Monakhov if (atomic_dec_and_test(&EXT4_I(inode)->i_unwritten)) 1144e298021STheodore Ts'o wake_up_all(ext4_ioend_wq(io->inode)); 115bd2d0210STheodore Ts'o return ret; 116bd2d0210STheodore Ts'o } 117bd2d0210STheodore Ts'o 118*28a535f9SDmitry Monakhov static void dump_completed_IO(struct inode *inode) 119*28a535f9SDmitry Monakhov { 120*28a535f9SDmitry Monakhov #ifdef EXT4FS_DEBUG 121*28a535f9SDmitry Monakhov struct list_head *cur, *before, *after; 122*28a535f9SDmitry Monakhov ext4_io_end_t *io, *io0, *io1; 123*28a535f9SDmitry Monakhov unsigned long flags; 124*28a535f9SDmitry Monakhov 125*28a535f9SDmitry Monakhov if (list_empty(&EXT4_I(inode)->i_completed_io_list)) { 126*28a535f9SDmitry Monakhov ext4_debug("inode %lu completed_io list is empty\n", 127*28a535f9SDmitry Monakhov inode->i_ino); 128*28a535f9SDmitry Monakhov return; 129*28a535f9SDmitry Monakhov } 130*28a535f9SDmitry Monakhov 131*28a535f9SDmitry Monakhov ext4_debug("Dump inode %lu completed_io list\n", inode->i_ino); 132*28a535f9SDmitry Monakhov list_for_each_entry(io, &EXT4_I(inode)->i_completed_io_list, list) { 133*28a535f9SDmitry Monakhov cur = &io->list; 134*28a535f9SDmitry Monakhov before = cur->prev; 135*28a535f9SDmitry Monakhov io0 = container_of(before, ext4_io_end_t, list); 136*28a535f9SDmitry Monakhov after = cur->next; 137*28a535f9SDmitry Monakhov io1 = container_of(after, ext4_io_end_t, list); 138*28a535f9SDmitry Monakhov 139*28a535f9SDmitry Monakhov ext4_debug("io 0x%p from inode %lu,prev 0x%p,next 0x%p\n", 140*28a535f9SDmitry Monakhov io, inode->i_ino, io0, io1); 141*28a535f9SDmitry Monakhov } 142*28a535f9SDmitry Monakhov #endif 143*28a535f9SDmitry Monakhov } 144*28a535f9SDmitry Monakhov 145*28a535f9SDmitry Monakhov /* Add the io_end to per-inode completed end_io list. */ 146*28a535f9SDmitry Monakhov void ext4_add_complete_io(ext4_io_end_t *io_end) 147*28a535f9SDmitry Monakhov { 148*28a535f9SDmitry Monakhov struct ext4_inode_info *ei = EXT4_I(io_end->inode); 149*28a535f9SDmitry Monakhov struct workqueue_struct *wq; 150*28a535f9SDmitry Monakhov unsigned long flags; 151*28a535f9SDmitry Monakhov 152*28a535f9SDmitry Monakhov BUG_ON(!(io_end->flag & EXT4_IO_END_UNWRITTEN)); 153*28a535f9SDmitry Monakhov wq = EXT4_SB(io_end->inode->i_sb)->dio_unwritten_wq; 154*28a535f9SDmitry Monakhov 155*28a535f9SDmitry Monakhov spin_lock_irqsave(&ei->i_completed_io_lock, flags); 156*28a535f9SDmitry Monakhov if (list_empty(&ei->i_completed_io_list)) { 157*28a535f9SDmitry Monakhov io_end->flag |= EXT4_IO_END_QUEUED; 158*28a535f9SDmitry Monakhov queue_work(wq, &io_end->work); 159*28a535f9SDmitry Monakhov } 160*28a535f9SDmitry Monakhov list_add_tail(&io_end->list, &ei->i_completed_io_list); 161*28a535f9SDmitry Monakhov spin_unlock_irqrestore(&ei->i_completed_io_lock, flags); 162*28a535f9SDmitry Monakhov } 163*28a535f9SDmitry Monakhov 164*28a535f9SDmitry Monakhov static int ext4_do_flush_completed_IO(struct inode *inode, 165*28a535f9SDmitry Monakhov ext4_io_end_t *work_io) 166*28a535f9SDmitry Monakhov { 167*28a535f9SDmitry Monakhov ext4_io_end_t *io; 168*28a535f9SDmitry Monakhov struct list_head unwritten, complete, to_free; 169*28a535f9SDmitry Monakhov unsigned long flags; 170*28a535f9SDmitry Monakhov struct ext4_inode_info *ei = EXT4_I(inode); 171*28a535f9SDmitry Monakhov int err, ret = 0; 172*28a535f9SDmitry Monakhov 173*28a535f9SDmitry Monakhov INIT_LIST_HEAD(&complete); 174*28a535f9SDmitry Monakhov INIT_LIST_HEAD(&to_free); 175*28a535f9SDmitry Monakhov 176*28a535f9SDmitry Monakhov spin_lock_irqsave(&ei->i_completed_io_lock, flags); 177*28a535f9SDmitry Monakhov dump_completed_IO(inode); 178*28a535f9SDmitry Monakhov list_replace_init(&ei->i_completed_io_list, &unwritten); 179*28a535f9SDmitry Monakhov spin_unlock_irqrestore(&ei->i_completed_io_lock, flags); 180*28a535f9SDmitry Monakhov 181*28a535f9SDmitry Monakhov while (!list_empty(&unwritten)) { 182*28a535f9SDmitry Monakhov io = list_entry(unwritten.next, ext4_io_end_t, list); 183*28a535f9SDmitry Monakhov BUG_ON(!(io->flag & EXT4_IO_END_UNWRITTEN)); 184*28a535f9SDmitry Monakhov list_del_init(&io->list); 185*28a535f9SDmitry Monakhov 186*28a535f9SDmitry Monakhov err = ext4_end_io(io); 187*28a535f9SDmitry Monakhov if (unlikely(!ret && err)) 188*28a535f9SDmitry Monakhov ret = err; 189*28a535f9SDmitry Monakhov 190*28a535f9SDmitry Monakhov list_add_tail(&io->list, &complete); 191*28a535f9SDmitry Monakhov } 192*28a535f9SDmitry Monakhov /* It is important to update all flags for all end_io in one shot w/o 193*28a535f9SDmitry Monakhov * dropping the lock.*/ 194*28a535f9SDmitry Monakhov spin_lock_irqsave(&ei->i_completed_io_lock, flags); 195*28a535f9SDmitry Monakhov while (!list_empty(&complete)) { 196*28a535f9SDmitry Monakhov io = list_entry(complete.next, ext4_io_end_t, list); 197*28a535f9SDmitry Monakhov io->flag &= ~EXT4_IO_END_UNWRITTEN; 198*28a535f9SDmitry Monakhov /* end_io context can not be destroyed now because it still 199*28a535f9SDmitry Monakhov * used by queued worker. Worker thread will destroy it later */ 200*28a535f9SDmitry Monakhov if (io->flag & EXT4_IO_END_QUEUED) 201*28a535f9SDmitry Monakhov list_del_init(&io->list); 202*28a535f9SDmitry Monakhov else 203*28a535f9SDmitry Monakhov list_move(&io->list, &to_free); 204*28a535f9SDmitry Monakhov } 205*28a535f9SDmitry Monakhov /* If we are called from worker context, it is time to clear queued 206*28a535f9SDmitry Monakhov * flag, and destroy it's end_io if it was converted already */ 207*28a535f9SDmitry Monakhov if (work_io) { 208*28a535f9SDmitry Monakhov work_io->flag &= ~EXT4_IO_END_QUEUED; 209*28a535f9SDmitry Monakhov if (!(work_io->flag & EXT4_IO_END_UNWRITTEN)) 210*28a535f9SDmitry Monakhov list_add_tail(&work_io->list, &to_free); 211*28a535f9SDmitry Monakhov } 212*28a535f9SDmitry Monakhov spin_unlock_irqrestore(&ei->i_completed_io_lock, flags); 213*28a535f9SDmitry Monakhov 214*28a535f9SDmitry Monakhov while (!list_empty(&to_free)) { 215*28a535f9SDmitry Monakhov io = list_entry(to_free.next, ext4_io_end_t, list); 216*28a535f9SDmitry Monakhov list_del_init(&io->list); 217*28a535f9SDmitry Monakhov ext4_free_io_end(io); 218*28a535f9SDmitry Monakhov } 219*28a535f9SDmitry Monakhov return ret; 220*28a535f9SDmitry Monakhov } 221*28a535f9SDmitry Monakhov 222bd2d0210STheodore Ts'o /* 223bd2d0210STheodore Ts'o * work on completed aio dio IO, to convert unwritten extents to extents 224bd2d0210STheodore Ts'o */ 225bd2d0210STheodore Ts'o static void ext4_end_io_work(struct work_struct *work) 226bd2d0210STheodore Ts'o { 227bd2d0210STheodore Ts'o ext4_io_end_t *io = container_of(work, ext4_io_end_t, work); 228*28a535f9SDmitry Monakhov ext4_do_flush_completed_IO(io->inode, io); 229d73d5046STao Ma } 230d73d5046STao Ma 231*28a535f9SDmitry Monakhov int ext4_flush_completed_IO(struct inode *inode) 232*28a535f9SDmitry Monakhov { 233*28a535f9SDmitry Monakhov return ext4_do_flush_completed_IO(inode, NULL); 234bd2d0210STheodore Ts'o } 235bd2d0210STheodore Ts'o 236bd2d0210STheodore Ts'o ext4_io_end_t *ext4_init_io_end(struct inode *inode, gfp_t flags) 237bd2d0210STheodore Ts'o { 238b17b35ecSJesper Juhl ext4_io_end_t *io = kmem_cache_zalloc(io_end_cachep, flags); 239bd2d0210STheodore Ts'o if (io) { 240f7ad6d2eSTheodore Ts'o atomic_inc(&EXT4_I(inode)->i_ioend_count); 241f7ad6d2eSTheodore Ts'o io->inode = inode; 242bd2d0210STheodore Ts'o INIT_WORK(&io->work, ext4_end_io_work); 243bd2d0210STheodore Ts'o INIT_LIST_HEAD(&io->list); 244bd2d0210STheodore Ts'o } 245bd2d0210STheodore Ts'o return io; 246bd2d0210STheodore Ts'o } 247bd2d0210STheodore Ts'o 248bd2d0210STheodore Ts'o /* 249bd2d0210STheodore Ts'o * Print an buffer I/O error compatible with the fs/buffer.c. This 250bd2d0210STheodore Ts'o * provides compatibility with dmesg scrapers that look for a specific 251bd2d0210STheodore Ts'o * buffer I/O error message. We really need a unified error reporting 252bd2d0210STheodore Ts'o * structure to userspace ala Digital Unix's uerf system, but it's 253bd2d0210STheodore Ts'o * probably not going to happen in my lifetime, due to LKML politics... 254bd2d0210STheodore Ts'o */ 255bd2d0210STheodore Ts'o static void buffer_io_error(struct buffer_head *bh) 256bd2d0210STheodore Ts'o { 257bd2d0210STheodore Ts'o char b[BDEVNAME_SIZE]; 258bd2d0210STheodore Ts'o printk(KERN_ERR "Buffer I/O error on device %s, logical block %llu\n", 259bd2d0210STheodore Ts'o bdevname(bh->b_bdev, b), 260bd2d0210STheodore Ts'o (unsigned long long)bh->b_blocknr); 261bd2d0210STheodore Ts'o } 262bd2d0210STheodore Ts'o 263bd2d0210STheodore Ts'o static void ext4_end_bio(struct bio *bio, int error) 264bd2d0210STheodore Ts'o { 265bd2d0210STheodore Ts'o ext4_io_end_t *io_end = bio->bi_private; 266bd2d0210STheodore Ts'o struct inode *inode; 267bd2d0210STheodore Ts'o int i; 268d50bdd5aSCurt Wohlgemuth sector_t bi_sector = bio->bi_sector; 269bd2d0210STheodore Ts'o 270bd2d0210STheodore Ts'o BUG_ON(!io_end); 271bd2d0210STheodore Ts'o bio->bi_private = NULL; 272bd2d0210STheodore Ts'o bio->bi_end_io = NULL; 273bd2d0210STheodore Ts'o if (test_bit(BIO_UPTODATE, &bio->bi_flags)) 274bd2d0210STheodore Ts'o error = 0; 275bd2d0210STheodore Ts'o bio_put(bio); 276bd2d0210STheodore Ts'o 277bd2d0210STheodore Ts'o for (i = 0; i < io_end->num_io_pages; i++) { 278bd2d0210STheodore Ts'o struct page *page = io_end->pages[i]->p_page; 279bd2d0210STheodore Ts'o struct buffer_head *bh, *head; 280bd2d0210STheodore Ts'o loff_t offset; 28139db00f1SCurt Wohlgemuth loff_t io_end_offset; 28239db00f1SCurt Wohlgemuth 28339db00f1SCurt Wohlgemuth if (error) { 28439db00f1SCurt Wohlgemuth SetPageError(page); 28539db00f1SCurt Wohlgemuth set_bit(AS_EIO, &page->mapping->flags); 28639db00f1SCurt Wohlgemuth head = page_buffers(page); 28739db00f1SCurt Wohlgemuth BUG_ON(!head); 28839db00f1SCurt Wohlgemuth 28939db00f1SCurt Wohlgemuth io_end_offset = io_end->offset + io_end->size; 290bd2d0210STheodore Ts'o 291bd2d0210STheodore Ts'o offset = (sector_t) page->index << PAGE_CACHE_SHIFT; 292bd2d0210STheodore Ts'o bh = head; 293bd2d0210STheodore Ts'o do { 294bd2d0210STheodore Ts'o if ((offset >= io_end->offset) && 29539db00f1SCurt Wohlgemuth (offset+bh->b_size <= io_end_offset)) 296bd2d0210STheodore Ts'o buffer_io_error(bh); 297bd2d0210STheodore Ts'o 298bd2d0210STheodore Ts'o offset += bh->b_size; 299bd2d0210STheodore Ts'o bh = bh->b_this_page; 300bd2d0210STheodore Ts'o } while (bh != head); 301bd2d0210STheodore Ts'o } 302bd2d0210STheodore Ts'o 3036268b325SLinus Torvalds put_io_page(io_end->pages[i]); 304bd2d0210STheodore Ts'o } 3056268b325SLinus Torvalds io_end->num_io_pages = 0; 306f7ad6d2eSTheodore Ts'o inode = io_end->inode; 307f7ad6d2eSTheodore Ts'o 308f7ad6d2eSTheodore Ts'o if (error) { 309f7ad6d2eSTheodore Ts'o io_end->flag |= EXT4_IO_END_ERROR; 310f7ad6d2eSTheodore Ts'o ext4_warning(inode->i_sb, "I/O error writing to inode %lu " 311f7ad6d2eSTheodore Ts'o "(offset %llu size %ld starting block %llu)", 312f7ad6d2eSTheodore Ts'o inode->i_ino, 313f7ad6d2eSTheodore Ts'o (unsigned long long) io_end->offset, 314f7ad6d2eSTheodore Ts'o (long) io_end->size, 315f7ad6d2eSTheodore Ts'o (unsigned long long) 316d50bdd5aSCurt Wohlgemuth bi_sector >> (inode->i_blkbits - 9)); 317f7ad6d2eSTheodore Ts'o } 318bd2d0210STheodore Ts'o 319b6168443STheodore Ts'o if (!(io_end->flag & EXT4_IO_END_UNWRITTEN)) { 320b6168443STheodore Ts'o ext4_free_io_end(io_end); 321b6168443STheodore Ts'o return; 322b6168443STheodore Ts'o } 323b6168443STheodore Ts'o 324*28a535f9SDmitry Monakhov ext4_add_complete_io(io_end); 325bd2d0210STheodore Ts'o } 326bd2d0210STheodore Ts'o 327bd2d0210STheodore Ts'o void ext4_io_submit(struct ext4_io_submit *io) 328bd2d0210STheodore Ts'o { 329bd2d0210STheodore Ts'o struct bio *bio = io->io_bio; 330bd2d0210STheodore Ts'o 331bd2d0210STheodore Ts'o if (bio) { 332bd2d0210STheodore Ts'o bio_get(io->io_bio); 333bd2d0210STheodore Ts'o submit_bio(io->io_op, io->io_bio); 334bd2d0210STheodore Ts'o BUG_ON(bio_flagged(io->io_bio, BIO_EOPNOTSUPP)); 335bd2d0210STheodore Ts'o bio_put(io->io_bio); 336bd2d0210STheodore Ts'o } 3377dc57615SPeter Huewe io->io_bio = NULL; 338bd2d0210STheodore Ts'o io->io_op = 0; 3397dc57615SPeter Huewe io->io_end = NULL; 340bd2d0210STheodore Ts'o } 341bd2d0210STheodore Ts'o 342bd2d0210STheodore Ts'o static int io_submit_init(struct ext4_io_submit *io, 343bd2d0210STheodore Ts'o struct inode *inode, 344bd2d0210STheodore Ts'o struct writeback_control *wbc, 345bd2d0210STheodore Ts'o struct buffer_head *bh) 346bd2d0210STheodore Ts'o { 347bd2d0210STheodore Ts'o ext4_io_end_t *io_end; 348bd2d0210STheodore Ts'o struct page *page = bh->b_page; 349bd2d0210STheodore Ts'o int nvecs = bio_get_nr_vecs(bh->b_bdev); 350bd2d0210STheodore Ts'o struct bio *bio; 351bd2d0210STheodore Ts'o 352bd2d0210STheodore Ts'o io_end = ext4_init_io_end(inode, GFP_NOFS); 353bd2d0210STheodore Ts'o if (!io_end) 354bd2d0210STheodore Ts'o return -ENOMEM; 355275d3ba6STheodore Ts'o bio = bio_alloc(GFP_NOIO, min(nvecs, BIO_MAX_PAGES)); 356bd2d0210STheodore Ts'o bio->bi_sector = bh->b_blocknr * (bh->b_size >> 9); 357bd2d0210STheodore Ts'o bio->bi_bdev = bh->b_bdev; 358bd2d0210STheodore Ts'o bio->bi_private = io->io_end = io_end; 359bd2d0210STheodore Ts'o bio->bi_end_io = ext4_end_bio; 360bd2d0210STheodore Ts'o 361bd2d0210STheodore Ts'o io_end->offset = (page->index << PAGE_CACHE_SHIFT) + bh_offset(bh); 362bd2d0210STheodore Ts'o 363bd2d0210STheodore Ts'o io->io_bio = bio; 364721a9602SJens Axboe io->io_op = (wbc->sync_mode == WB_SYNC_ALL ? WRITE_SYNC : WRITE); 365bd2d0210STheodore Ts'o io->io_next_block = bh->b_blocknr; 366bd2d0210STheodore Ts'o return 0; 367bd2d0210STheodore Ts'o } 368bd2d0210STheodore Ts'o 369bd2d0210STheodore Ts'o static int io_submit_add_bh(struct ext4_io_submit *io, 370bd2d0210STheodore Ts'o struct ext4_io_page *io_page, 371bd2d0210STheodore Ts'o struct inode *inode, 372bd2d0210STheodore Ts'o struct writeback_control *wbc, 373bd2d0210STheodore Ts'o struct buffer_head *bh) 374bd2d0210STheodore Ts'o { 375bd2d0210STheodore Ts'o ext4_io_end_t *io_end; 376bd2d0210STheodore Ts'o int ret; 377bd2d0210STheodore Ts'o 378bd2d0210STheodore Ts'o if (buffer_new(bh)) { 379bd2d0210STheodore Ts'o clear_buffer_new(bh); 380bd2d0210STheodore Ts'o unmap_underlying_metadata(bh->b_bdev, bh->b_blocknr); 381bd2d0210STheodore Ts'o } 382bd2d0210STheodore Ts'o 383bd2d0210STheodore Ts'o if (!buffer_mapped(bh) || buffer_delay(bh)) { 384bd2d0210STheodore Ts'o if (!buffer_mapped(bh)) 385bd2d0210STheodore Ts'o clear_buffer_dirty(bh); 386bd2d0210STheodore Ts'o if (io->io_bio) 387bd2d0210STheodore Ts'o ext4_io_submit(io); 388bd2d0210STheodore Ts'o return 0; 389bd2d0210STheodore Ts'o } 390bd2d0210STheodore Ts'o 391bd2d0210STheodore Ts'o if (io->io_bio && bh->b_blocknr != io->io_next_block) { 392bd2d0210STheodore Ts'o submit_and_retry: 393bd2d0210STheodore Ts'o ext4_io_submit(io); 394bd2d0210STheodore Ts'o } 395bd2d0210STheodore Ts'o if (io->io_bio == NULL) { 396bd2d0210STheodore Ts'o ret = io_submit_init(io, inode, wbc, bh); 397bd2d0210STheodore Ts'o if (ret) 398bd2d0210STheodore Ts'o return ret; 399bd2d0210STheodore Ts'o } 400bd2d0210STheodore Ts'o io_end = io->io_end; 401bd2d0210STheodore Ts'o if ((io_end->num_io_pages >= MAX_IO_PAGES) && 402bd2d0210STheodore Ts'o (io_end->pages[io_end->num_io_pages-1] != io_page)) 403bd2d0210STheodore Ts'o goto submit_and_retry; 4040edeb71dSTao Ma if (buffer_uninit(bh)) 4050edeb71dSTao Ma ext4_set_io_unwritten_flag(inode, io_end); 406bd2d0210STheodore Ts'o io->io_end->size += bh->b_size; 407bd2d0210STheodore Ts'o io->io_next_block++; 408bd2d0210STheodore Ts'o ret = bio_add_page(io->io_bio, bh->b_page, bh->b_size, bh_offset(bh)); 409bd2d0210STheodore Ts'o if (ret != bh->b_size) 410bd2d0210STheodore Ts'o goto submit_and_retry; 411bd2d0210STheodore Ts'o if ((io_end->num_io_pages == 0) || 412bd2d0210STheodore Ts'o (io_end->pages[io_end->num_io_pages-1] != io_page)) { 413bd2d0210STheodore Ts'o io_end->pages[io_end->num_io_pages++] = io_page; 41483668e71STheodore Ts'o atomic_inc(&io_page->p_count); 415bd2d0210STheodore Ts'o } 416bd2d0210STheodore Ts'o return 0; 417bd2d0210STheodore Ts'o } 418bd2d0210STheodore Ts'o 419bd2d0210STheodore Ts'o int ext4_bio_write_page(struct ext4_io_submit *io, 420bd2d0210STheodore Ts'o struct page *page, 421bd2d0210STheodore Ts'o int len, 422bd2d0210STheodore Ts'o struct writeback_control *wbc) 423bd2d0210STheodore Ts'o { 424bd2d0210STheodore Ts'o struct inode *inode = page->mapping->host; 425bd2d0210STheodore Ts'o unsigned block_start, block_end, blocksize; 426bd2d0210STheodore Ts'o struct ext4_io_page *io_page; 427bd2d0210STheodore Ts'o struct buffer_head *bh, *head; 428bd2d0210STheodore Ts'o int ret = 0; 429bd2d0210STheodore Ts'o 430bd2d0210STheodore Ts'o blocksize = 1 << inode->i_blkbits; 431bd2d0210STheodore Ts'o 432d50bdd5aSCurt Wohlgemuth BUG_ON(!PageLocked(page)); 433bd2d0210STheodore Ts'o BUG_ON(PageWriteback(page)); 434bd2d0210STheodore Ts'o 435bd2d0210STheodore Ts'o io_page = kmem_cache_alloc(io_page_cachep, GFP_NOFS); 436bd2d0210STheodore Ts'o if (!io_page) { 437bd2d0210STheodore Ts'o set_page_dirty(page); 438bd2d0210STheodore Ts'o unlock_page(page); 439bd2d0210STheodore Ts'o return -ENOMEM; 440bd2d0210STheodore Ts'o } 441bd2d0210STheodore Ts'o io_page->p_page = page; 44283668e71STheodore Ts'o atomic_set(&io_page->p_count, 1); 443bd2d0210STheodore Ts'o get_page(page); 444a54aa761STheodore Ts'o set_page_writeback(page); 445a54aa761STheodore Ts'o ClearPageError(page); 446bd2d0210STheodore Ts'o 447bd2d0210STheodore Ts'o for (bh = head = page_buffers(page), block_start = 0; 448bd2d0210STheodore Ts'o bh != head || !block_start; 449bd2d0210STheodore Ts'o block_start = block_end, bh = bh->b_this_page) { 450d50bdd5aSCurt Wohlgemuth 451bd2d0210STheodore Ts'o block_end = block_start + blocksize; 452bd2d0210STheodore Ts'o if (block_start >= len) { 4535a0dc736SYongqiang Yang /* 4545a0dc736SYongqiang Yang * Comments copied from block_write_full_page_endio: 4555a0dc736SYongqiang Yang * 4565a0dc736SYongqiang Yang * The page straddles i_size. It must be zeroed out on 4575a0dc736SYongqiang Yang * each and every writepage invocation because it may 4585a0dc736SYongqiang Yang * be mmapped. "A file is mapped in multiples of the 4595a0dc736SYongqiang Yang * page size. For a file that is not a multiple of 4605a0dc736SYongqiang Yang * the page size, the remaining memory is zeroed when 4615a0dc736SYongqiang Yang * mapped, and writes to that region are not written 4625a0dc736SYongqiang Yang * out to the file." 4635a0dc736SYongqiang Yang */ 4645a0dc736SYongqiang Yang zero_user_segment(page, block_start, block_end); 465bd2d0210STheodore Ts'o clear_buffer_dirty(bh); 466bd2d0210STheodore Ts'o set_buffer_uptodate(bh); 467bd2d0210STheodore Ts'o continue; 468bd2d0210STheodore Ts'o } 469d50bdd5aSCurt Wohlgemuth clear_buffer_dirty(bh); 470bd2d0210STheodore Ts'o ret = io_submit_add_bh(io, io_page, inode, wbc, bh); 471bd2d0210STheodore Ts'o if (ret) { 472bd2d0210STheodore Ts'o /* 473bd2d0210STheodore Ts'o * We only get here on ENOMEM. Not much else 474bd2d0210STheodore Ts'o * we can do but mark the page as dirty, and 475bd2d0210STheodore Ts'o * better luck next time. 476bd2d0210STheodore Ts'o */ 477bd2d0210STheodore Ts'o set_page_dirty(page); 478bd2d0210STheodore Ts'o break; 479bd2d0210STheodore Ts'o } 480bd2d0210STheodore Ts'o } 481bd2d0210STheodore Ts'o unlock_page(page); 482bd2d0210STheodore Ts'o /* 483bd2d0210STheodore Ts'o * If the page was truncated before we could do the writeback, 484bd2d0210STheodore Ts'o * or we had a memory allocation error while trying to write 485bd2d0210STheodore Ts'o * the first buffer head, we won't have submitted any pages for 486bd2d0210STheodore Ts'o * I/O. In that case we need to make sure we've cleared the 487bd2d0210STheodore Ts'o * PageWriteback bit from the page to prevent the system from 488bd2d0210STheodore Ts'o * wedging later on. 489bd2d0210STheodore Ts'o */ 49083668e71STheodore Ts'o put_io_page(io_page); 491bd2d0210STheodore Ts'o return ret; 492bd2d0210STheodore Ts'o } 493