11da177e4SLinus Torvalds /* 21da177e4SLinus Torvalds * JFFS2 -- Journalling Flash File System, Version 2. 31da177e4SLinus Torvalds * 4c00c310eSDavid Woodhouse * Copyright © 2001-2007 Red Hat, Inc. 51da177e4SLinus Torvalds * 61da177e4SLinus Torvalds * Created by David Woodhouse <dwmw2@infradead.org> 71da177e4SLinus Torvalds * 81da177e4SLinus Torvalds * For licensing information, see the file 'LICENCE' in this directory. 91da177e4SLinus Torvalds * 101da177e4SLinus Torvalds */ 111da177e4SLinus Torvalds 121da177e4SLinus Torvalds #include <linux/kernel.h> 131da177e4SLinus Torvalds #include <linux/slab.h> 141da177e4SLinus Torvalds #include <linux/fs.h> 151da177e4SLinus Torvalds #include <linux/time.h> 161da177e4SLinus Torvalds #include <linux/pagemap.h> 171da177e4SLinus Torvalds #include <linux/highmem.h> 181da177e4SLinus Torvalds #include <linux/crc32.h> 191da177e4SLinus Torvalds #include <linux/jffs2.h> 201da177e4SLinus Torvalds #include "nodelist.h" 211da177e4SLinus Torvalds 221da177e4SLinus Torvalds static int jffs2_commit_write (struct file *filp, struct page *pg, 231da177e4SLinus Torvalds unsigned start, unsigned end); 241da177e4SLinus Torvalds static int jffs2_prepare_write (struct file *filp, struct page *pg, 251da177e4SLinus Torvalds unsigned start, unsigned end); 261da177e4SLinus Torvalds static int jffs2_readpage (struct file *filp, struct page *pg); 271da177e4SLinus Torvalds 281da177e4SLinus Torvalds int jffs2_fsync(struct file *filp, struct dentry *dentry, int datasync) 291da177e4SLinus Torvalds { 301da177e4SLinus Torvalds struct inode *inode = dentry->d_inode; 311da177e4SLinus Torvalds struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb); 321da177e4SLinus Torvalds 331da177e4SLinus Torvalds /* Trigger GC to flush any pending writes for this inode */ 341da177e4SLinus Torvalds jffs2_flush_wbuf_gc(c, inode->i_ino); 351da177e4SLinus Torvalds 361da177e4SLinus Torvalds return 0; 371da177e4SLinus Torvalds } 381da177e4SLinus Torvalds 394b6f5d20SArjan van de Ven const struct file_operations jffs2_file_operations = 401da177e4SLinus Torvalds { 411da177e4SLinus Torvalds .llseek = generic_file_llseek, 421da177e4SLinus Torvalds .open = generic_file_open, 43543ade1fSBadari Pulavarty .read = do_sync_read, 44543ade1fSBadari Pulavarty .aio_read = generic_file_aio_read, 45543ade1fSBadari Pulavarty .write = do_sync_write, 46543ade1fSBadari Pulavarty .aio_write = generic_file_aio_write, 471da177e4SLinus Torvalds .ioctl = jffs2_ioctl, 481da177e4SLinus Torvalds .mmap = generic_file_readonly_mmap, 491da177e4SLinus Torvalds .fsync = jffs2_fsync, 501da177e4SLinus Torvalds .sendfile = generic_file_sendfile 511da177e4SLinus Torvalds }; 521da177e4SLinus Torvalds 531da177e4SLinus Torvalds /* jffs2_file_inode_operations */ 541da177e4SLinus Torvalds 5592e1d5beSArjan van de Ven const struct inode_operations jffs2_file_inode_operations = 561da177e4SLinus Torvalds { 57aa98d7cfSKaiGai Kohei .permission = jffs2_permission, 58aa98d7cfSKaiGai Kohei .setattr = jffs2_setattr, 59aa98d7cfSKaiGai Kohei .setxattr = jffs2_setxattr, 60aa98d7cfSKaiGai Kohei .getxattr = jffs2_getxattr, 61aa98d7cfSKaiGai Kohei .listxattr = jffs2_listxattr, 62aa98d7cfSKaiGai Kohei .removexattr = jffs2_removexattr 631da177e4SLinus Torvalds }; 641da177e4SLinus Torvalds 65f5e54d6eSChristoph Hellwig const struct address_space_operations jffs2_file_address_operations = 661da177e4SLinus Torvalds { 671da177e4SLinus Torvalds .readpage = jffs2_readpage, 681da177e4SLinus Torvalds .prepare_write =jffs2_prepare_write, 691da177e4SLinus Torvalds .commit_write = jffs2_commit_write 701da177e4SLinus Torvalds }; 711da177e4SLinus Torvalds 721da177e4SLinus Torvalds static int jffs2_do_readpage_nolock (struct inode *inode, struct page *pg) 731da177e4SLinus Torvalds { 741da177e4SLinus Torvalds struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode); 751da177e4SLinus Torvalds struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb); 761da177e4SLinus Torvalds unsigned char *pg_buf; 771da177e4SLinus Torvalds int ret; 781da177e4SLinus Torvalds 791da177e4SLinus Torvalds D2(printk(KERN_DEBUG "jffs2_do_readpage_nolock(): ino #%lu, page at offset 0x%lx\n", inode->i_ino, pg->index << PAGE_CACHE_SHIFT)); 801da177e4SLinus Torvalds 81cd7619d6SMatt Mackall BUG_ON(!PageLocked(pg)); 821da177e4SLinus Torvalds 831da177e4SLinus Torvalds pg_buf = kmap(pg); 841da177e4SLinus Torvalds /* FIXME: Can kmap fail? */ 851da177e4SLinus Torvalds 861da177e4SLinus Torvalds ret = jffs2_read_inode_range(c, f, pg_buf, pg->index << PAGE_CACHE_SHIFT, PAGE_CACHE_SIZE); 871da177e4SLinus Torvalds 881da177e4SLinus Torvalds if (ret) { 891da177e4SLinus Torvalds ClearPageUptodate(pg); 901da177e4SLinus Torvalds SetPageError(pg); 911da177e4SLinus Torvalds } else { 921da177e4SLinus Torvalds SetPageUptodate(pg); 931da177e4SLinus Torvalds ClearPageError(pg); 941da177e4SLinus Torvalds } 951da177e4SLinus Torvalds 961da177e4SLinus Torvalds flush_dcache_page(pg); 971da177e4SLinus Torvalds kunmap(pg); 981da177e4SLinus Torvalds 991da177e4SLinus Torvalds D2(printk(KERN_DEBUG "readpage finished\n")); 1001da177e4SLinus Torvalds return 0; 1011da177e4SLinus Torvalds } 1021da177e4SLinus Torvalds 1031da177e4SLinus Torvalds int jffs2_do_readpage_unlock(struct inode *inode, struct page *pg) 1041da177e4SLinus Torvalds { 1051da177e4SLinus Torvalds int ret = jffs2_do_readpage_nolock(inode, pg); 1061da177e4SLinus Torvalds unlock_page(pg); 1071da177e4SLinus Torvalds return ret; 1081da177e4SLinus Torvalds } 1091da177e4SLinus Torvalds 1101da177e4SLinus Torvalds 1111da177e4SLinus Torvalds static int jffs2_readpage (struct file *filp, struct page *pg) 1121da177e4SLinus Torvalds { 1131da177e4SLinus Torvalds struct jffs2_inode_info *f = JFFS2_INODE_INFO(pg->mapping->host); 1141da177e4SLinus Torvalds int ret; 1151da177e4SLinus Torvalds 1161da177e4SLinus Torvalds down(&f->sem); 1171da177e4SLinus Torvalds ret = jffs2_do_readpage_unlock(pg->mapping->host, pg); 1181da177e4SLinus Torvalds up(&f->sem); 1191da177e4SLinus Torvalds return ret; 1201da177e4SLinus Torvalds } 1211da177e4SLinus Torvalds 1221da177e4SLinus Torvalds static int jffs2_prepare_write (struct file *filp, struct page *pg, 1231da177e4SLinus Torvalds unsigned start, unsigned end) 1241da177e4SLinus Torvalds { 1251da177e4SLinus Torvalds struct inode *inode = pg->mapping->host; 1261da177e4SLinus Torvalds struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode); 1271da177e4SLinus Torvalds uint32_t pageofs = pg->index << PAGE_CACHE_SHIFT; 1281da177e4SLinus Torvalds int ret = 0; 1291da177e4SLinus Torvalds 1301da177e4SLinus Torvalds D1(printk(KERN_DEBUG "jffs2_prepare_write()\n")); 1311da177e4SLinus Torvalds 1321da177e4SLinus Torvalds if (pageofs > inode->i_size) { 1331da177e4SLinus Torvalds /* Make new hole frag from old EOF to new page */ 1341da177e4SLinus Torvalds struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb); 1351da177e4SLinus Torvalds struct jffs2_raw_inode ri; 1361da177e4SLinus Torvalds struct jffs2_full_dnode *fn; 1379fe4854cSDavid Woodhouse uint32_t alloc_len; 1381da177e4SLinus Torvalds 1391da177e4SLinus Torvalds D1(printk(KERN_DEBUG "Writing new hole frag 0x%x-0x%x between current EOF and new page\n", 1401da177e4SLinus Torvalds (unsigned int)inode->i_size, pageofs)); 1411da177e4SLinus Torvalds 1429fe4854cSDavid Woodhouse ret = jffs2_reserve_space(c, sizeof(ri), &alloc_len, 143e631ddbaSFerenc Havasi ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE); 1441da177e4SLinus Torvalds if (ret) 1451da177e4SLinus Torvalds return ret; 1461da177e4SLinus Torvalds 1471da177e4SLinus Torvalds down(&f->sem); 1481da177e4SLinus Torvalds memset(&ri, 0, sizeof(ri)); 1491da177e4SLinus Torvalds 1501da177e4SLinus Torvalds ri.magic = cpu_to_je16(JFFS2_MAGIC_BITMASK); 1511da177e4SLinus Torvalds ri.nodetype = cpu_to_je16(JFFS2_NODETYPE_INODE); 1521da177e4SLinus Torvalds ri.totlen = cpu_to_je32(sizeof(ri)); 1531da177e4SLinus Torvalds ri.hdr_crc = cpu_to_je32(crc32(0, &ri, sizeof(struct jffs2_unknown_node)-4)); 1541da177e4SLinus Torvalds 1551da177e4SLinus Torvalds ri.ino = cpu_to_je32(f->inocache->ino); 1561da177e4SLinus Torvalds ri.version = cpu_to_je32(++f->highest_version); 1571da177e4SLinus Torvalds ri.mode = cpu_to_jemode(inode->i_mode); 1581da177e4SLinus Torvalds ri.uid = cpu_to_je16(inode->i_uid); 1591da177e4SLinus Torvalds ri.gid = cpu_to_je16(inode->i_gid); 1601da177e4SLinus Torvalds ri.isize = cpu_to_je32(max((uint32_t)inode->i_size, pageofs)); 1611da177e4SLinus Torvalds ri.atime = ri.ctime = ri.mtime = cpu_to_je32(get_seconds()); 1621da177e4SLinus Torvalds ri.offset = cpu_to_je32(inode->i_size); 1631da177e4SLinus Torvalds ri.dsize = cpu_to_je32(pageofs - inode->i_size); 1641da177e4SLinus Torvalds ri.csize = cpu_to_je32(0); 1651da177e4SLinus Torvalds ri.compr = JFFS2_COMPR_ZERO; 1661da177e4SLinus Torvalds ri.node_crc = cpu_to_je32(crc32(0, &ri, sizeof(ri)-8)); 1671da177e4SLinus Torvalds ri.data_crc = cpu_to_je32(0); 1681da177e4SLinus Torvalds 1699fe4854cSDavid Woodhouse fn = jffs2_write_dnode(c, f, &ri, NULL, 0, ALLOC_NORMAL); 1701da177e4SLinus Torvalds 1711da177e4SLinus Torvalds if (IS_ERR(fn)) { 1721da177e4SLinus Torvalds ret = PTR_ERR(fn); 1731da177e4SLinus Torvalds jffs2_complete_reservation(c); 1741da177e4SLinus Torvalds up(&f->sem); 1751da177e4SLinus Torvalds return ret; 1761da177e4SLinus Torvalds } 1771da177e4SLinus Torvalds ret = jffs2_add_full_dnode_to_inode(c, f, fn); 1781da177e4SLinus Torvalds if (f->metadata) { 1791da177e4SLinus Torvalds jffs2_mark_node_obsolete(c, f->metadata->raw); 1801da177e4SLinus Torvalds jffs2_free_full_dnode(f->metadata); 1811da177e4SLinus Torvalds f->metadata = NULL; 1821da177e4SLinus Torvalds } 1831da177e4SLinus Torvalds if (ret) { 1841da177e4SLinus Torvalds D1(printk(KERN_DEBUG "Eep. add_full_dnode_to_inode() failed in prepare_write, returned %d\n", ret)); 1851da177e4SLinus Torvalds jffs2_mark_node_obsolete(c, fn->raw); 1861da177e4SLinus Torvalds jffs2_free_full_dnode(fn); 1871da177e4SLinus Torvalds jffs2_complete_reservation(c); 1881da177e4SLinus Torvalds up(&f->sem); 1891da177e4SLinus Torvalds return ret; 1901da177e4SLinus Torvalds } 1911da177e4SLinus Torvalds jffs2_complete_reservation(c); 1921da177e4SLinus Torvalds inode->i_size = pageofs; 1931da177e4SLinus Torvalds up(&f->sem); 1941da177e4SLinus Torvalds } 1951da177e4SLinus Torvalds 1961da177e4SLinus Torvalds /* Read in the page if it wasn't already present, unless it's a whole page */ 1971da177e4SLinus Torvalds if (!PageUptodate(pg) && (start || end < PAGE_CACHE_SIZE)) { 1981da177e4SLinus Torvalds down(&f->sem); 1991da177e4SLinus Torvalds ret = jffs2_do_readpage_nolock(inode, pg); 2001da177e4SLinus Torvalds up(&f->sem); 2011da177e4SLinus Torvalds } 2021da177e4SLinus Torvalds D1(printk(KERN_DEBUG "end prepare_write(). pg->flags %lx\n", pg->flags)); 2031da177e4SLinus Torvalds return ret; 2041da177e4SLinus Torvalds } 2051da177e4SLinus Torvalds 2061da177e4SLinus Torvalds static int jffs2_commit_write (struct file *filp, struct page *pg, 2071da177e4SLinus Torvalds unsigned start, unsigned end) 2081da177e4SLinus Torvalds { 2091da177e4SLinus Torvalds /* Actually commit the write from the page cache page we're looking at. 2101da177e4SLinus Torvalds * For now, we write the full page out each time. It sucks, but it's simple 2111da177e4SLinus Torvalds */ 2121da177e4SLinus Torvalds struct inode *inode = pg->mapping->host; 2131da177e4SLinus Torvalds struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode); 2141da177e4SLinus Torvalds struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb); 2151da177e4SLinus Torvalds struct jffs2_raw_inode *ri; 2161da177e4SLinus Torvalds unsigned aligned_start = start & ~3; 2171da177e4SLinus Torvalds int ret = 0; 2181da177e4SLinus Torvalds uint32_t writtenlen = 0; 2191da177e4SLinus Torvalds 2201da177e4SLinus Torvalds D1(printk(KERN_DEBUG "jffs2_commit_write(): ino #%lu, page at 0x%lx, range %d-%d, flags %lx\n", 2211da177e4SLinus Torvalds inode->i_ino, pg->index << PAGE_CACHE_SHIFT, start, end, pg->flags)); 2221da177e4SLinus Torvalds 223cf5eba53SDavid Woodhouse if (end == PAGE_CACHE_SIZE) { 224cf5eba53SDavid Woodhouse if (!start) { 2251da177e4SLinus Torvalds /* We need to avoid deadlock with page_cache_read() in 2261da177e4SLinus Torvalds jffs2_garbage_collect_pass(). So we have to mark the 2271da177e4SLinus Torvalds page up to date, to prevent page_cache_read() from 2281da177e4SLinus Torvalds trying to re-lock it. */ 2291da177e4SLinus Torvalds SetPageUptodate(pg); 230cf5eba53SDavid Woodhouse } else { 231cf5eba53SDavid Woodhouse /* When writing out the end of a page, write out the 232cf5eba53SDavid Woodhouse _whole_ page. This helps to reduce the number of 233cf5eba53SDavid Woodhouse nodes in files which have many short writes, like 234cf5eba53SDavid Woodhouse syslog files. */ 235cf5eba53SDavid Woodhouse start = aligned_start = 0; 236cf5eba53SDavid Woodhouse } 2371da177e4SLinus Torvalds } 2381da177e4SLinus Torvalds 2391da177e4SLinus Torvalds ri = jffs2_alloc_raw_inode(); 2401da177e4SLinus Torvalds 2411da177e4SLinus Torvalds if (!ri) { 2421da177e4SLinus Torvalds D1(printk(KERN_DEBUG "jffs2_commit_write(): Allocation of raw inode failed\n")); 2431da177e4SLinus Torvalds return -ENOMEM; 2441da177e4SLinus Torvalds } 2451da177e4SLinus Torvalds 2461da177e4SLinus Torvalds /* Set the fields that the generic jffs2_write_inode_range() code can't find */ 2471da177e4SLinus Torvalds ri->ino = cpu_to_je32(inode->i_ino); 2481da177e4SLinus Torvalds ri->mode = cpu_to_jemode(inode->i_mode); 2491da177e4SLinus Torvalds ri->uid = cpu_to_je16(inode->i_uid); 2501da177e4SLinus Torvalds ri->gid = cpu_to_je16(inode->i_gid); 2511da177e4SLinus Torvalds ri->isize = cpu_to_je32((uint32_t)inode->i_size); 2521da177e4SLinus Torvalds ri->atime = ri->ctime = ri->mtime = cpu_to_je32(get_seconds()); 2531da177e4SLinus Torvalds 2541da177e4SLinus Torvalds /* In 2.4, it was already kmapped by generic_file_write(). Doesn't 2551da177e4SLinus Torvalds hurt to do it again. The alternative is ifdefs, which are ugly. */ 2561da177e4SLinus Torvalds kmap(pg); 2571da177e4SLinus Torvalds 2581da177e4SLinus Torvalds ret = jffs2_write_inode_range(c, f, ri, page_address(pg) + aligned_start, 2591da177e4SLinus Torvalds (pg->index << PAGE_CACHE_SHIFT) + aligned_start, 2601da177e4SLinus Torvalds end - aligned_start, &writtenlen); 2611da177e4SLinus Torvalds 2621da177e4SLinus Torvalds kunmap(pg); 2631da177e4SLinus Torvalds 2641da177e4SLinus Torvalds if (ret) { 2651da177e4SLinus Torvalds /* There was an error writing. */ 2661da177e4SLinus Torvalds SetPageError(pg); 2671da177e4SLinus Torvalds } 2681da177e4SLinus Torvalds 2691da177e4SLinus Torvalds /* Adjust writtenlen for the padding we did, so we don't confuse our caller */ 2701da177e4SLinus Torvalds if (writtenlen < (start&3)) 2711da177e4SLinus Torvalds writtenlen = 0; 2721da177e4SLinus Torvalds else 2731da177e4SLinus Torvalds writtenlen -= (start&3); 2741da177e4SLinus Torvalds 2751da177e4SLinus Torvalds if (writtenlen) { 2761da177e4SLinus Torvalds if (inode->i_size < (pg->index << PAGE_CACHE_SHIFT) + start + writtenlen) { 2771da177e4SLinus Torvalds inode->i_size = (pg->index << PAGE_CACHE_SHIFT) + start + writtenlen; 2781da177e4SLinus Torvalds inode->i_blocks = (inode->i_size + 511) >> 9; 2791da177e4SLinus Torvalds 2801da177e4SLinus Torvalds inode->i_ctime = inode->i_mtime = ITIME(je32_to_cpu(ri->ctime)); 2811da177e4SLinus Torvalds } 2821da177e4SLinus Torvalds } 2831da177e4SLinus Torvalds 2841da177e4SLinus Torvalds jffs2_free_raw_inode(ri); 2851da177e4SLinus Torvalds 2861da177e4SLinus Torvalds if (start+writtenlen < end) { 2871da177e4SLinus Torvalds /* generic_file_write has written more to the page cache than we've 2881da177e4SLinus Torvalds actually written to the medium. Mark the page !Uptodate so that 2891da177e4SLinus Torvalds it gets reread */ 2901da177e4SLinus Torvalds D1(printk(KERN_DEBUG "jffs2_commit_write(): Not all bytes written. Marking page !uptodate\n")); 2911da177e4SLinus Torvalds SetPageError(pg); 2921da177e4SLinus Torvalds ClearPageUptodate(pg); 2931da177e4SLinus Torvalds } 2941da177e4SLinus Torvalds 2954fc67fbeSTodd Poynor D1(printk(KERN_DEBUG "jffs2_commit_write() returning %d\n",start+writtenlen==end?0:ret)); 2964fc67fbeSTodd Poynor return start+writtenlen==end?0:ret; 2971da177e4SLinus Torvalds } 298