1 /* 2 * JFFS2 -- Journalling Flash File System, Version 2. 3 * 4 * Copyright (C) 2001-2003 Red Hat, Inc. 5 * 6 * Created by David Woodhouse <dwmw2@infradead.org> 7 * 8 * For licensing information, see the file 'LICENCE' in this directory. 9 * 10 * $Id: file.c,v 1.104 2005/10/18 23:29:35 tpoynor Exp $ 11 * 12 */ 13 14 #include <linux/kernel.h> 15 #include <linux/slab.h> 16 #include <linux/fs.h> 17 #include <linux/time.h> 18 #include <linux/pagemap.h> 19 #include <linux/highmem.h> 20 #include <linux/crc32.h> 21 #include <linux/jffs2.h> 22 #include "nodelist.h" 23 24 static int jffs2_commit_write (struct file *filp, struct page *pg, 25 unsigned start, unsigned end); 26 static int jffs2_prepare_write (struct file *filp, struct page *pg, 27 unsigned start, unsigned end); 28 static int jffs2_readpage (struct file *filp, struct page *pg); 29 30 int jffs2_fsync(struct file *filp, struct dentry *dentry, int datasync) 31 { 32 struct inode *inode = dentry->d_inode; 33 struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb); 34 35 /* Trigger GC to flush any pending writes for this inode */ 36 jffs2_flush_wbuf_gc(c, inode->i_ino); 37 38 return 0; 39 } 40 41 struct file_operations jffs2_file_operations = 42 { 43 .llseek = generic_file_llseek, 44 .open = generic_file_open, 45 .read = generic_file_read, 46 .write = generic_file_write, 47 .ioctl = jffs2_ioctl, 48 .mmap = generic_file_readonly_mmap, 49 .fsync = jffs2_fsync, 50 .sendfile = generic_file_sendfile 51 }; 52 53 /* jffs2_file_inode_operations */ 54 55 struct inode_operations jffs2_file_inode_operations = 56 { 57 .setattr = jffs2_setattr 58 }; 59 60 struct address_space_operations jffs2_file_address_operations = 61 { 62 .readpage = jffs2_readpage, 63 .prepare_write =jffs2_prepare_write, 64 .commit_write = jffs2_commit_write 65 }; 66 67 static int jffs2_do_readpage_nolock (struct inode *inode, struct page *pg) 68 { 69 struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode); 70 struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb); 71 unsigned char *pg_buf; 72 int ret; 73 74 D2(printk(KERN_DEBUG "jffs2_do_readpage_nolock(): ino #%lu, page at offset 0x%lx\n", inode->i_ino, pg->index << PAGE_CACHE_SHIFT)); 75 76 BUG_ON(!PageLocked(pg)); 77 78 pg_buf = kmap(pg); 79 /* FIXME: Can kmap fail? */ 80 81 ret = jffs2_read_inode_range(c, f, pg_buf, pg->index << PAGE_CACHE_SHIFT, PAGE_CACHE_SIZE); 82 83 if (ret) { 84 ClearPageUptodate(pg); 85 SetPageError(pg); 86 } else { 87 SetPageUptodate(pg); 88 ClearPageError(pg); 89 } 90 91 flush_dcache_page(pg); 92 kunmap(pg); 93 94 D2(printk(KERN_DEBUG "readpage finished\n")); 95 return 0; 96 } 97 98 int jffs2_do_readpage_unlock(struct inode *inode, struct page *pg) 99 { 100 int ret = jffs2_do_readpage_nolock(inode, pg); 101 unlock_page(pg); 102 return ret; 103 } 104 105 106 static int jffs2_readpage (struct file *filp, struct page *pg) 107 { 108 struct jffs2_inode_info *f = JFFS2_INODE_INFO(pg->mapping->host); 109 int ret; 110 111 down(&f->sem); 112 ret = jffs2_do_readpage_unlock(pg->mapping->host, pg); 113 up(&f->sem); 114 return ret; 115 } 116 117 static int jffs2_prepare_write (struct file *filp, struct page *pg, 118 unsigned start, unsigned end) 119 { 120 struct inode *inode = pg->mapping->host; 121 struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode); 122 uint32_t pageofs = pg->index << PAGE_CACHE_SHIFT; 123 int ret = 0; 124 125 D1(printk(KERN_DEBUG "jffs2_prepare_write()\n")); 126 127 if (pageofs > inode->i_size) { 128 /* Make new hole frag from old EOF to new page */ 129 struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb); 130 struct jffs2_raw_inode ri; 131 struct jffs2_full_dnode *fn; 132 uint32_t phys_ofs, alloc_len; 133 134 D1(printk(KERN_DEBUG "Writing new hole frag 0x%x-0x%x between current EOF and new page\n", 135 (unsigned int)inode->i_size, pageofs)); 136 137 ret = jffs2_reserve_space(c, sizeof(ri), &phys_ofs, &alloc_len, 138 ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE); 139 if (ret) 140 return ret; 141 142 down(&f->sem); 143 memset(&ri, 0, sizeof(ri)); 144 145 ri.magic = cpu_to_je16(JFFS2_MAGIC_BITMASK); 146 ri.nodetype = cpu_to_je16(JFFS2_NODETYPE_INODE); 147 ri.totlen = cpu_to_je32(sizeof(ri)); 148 ri.hdr_crc = cpu_to_je32(crc32(0, &ri, sizeof(struct jffs2_unknown_node)-4)); 149 150 ri.ino = cpu_to_je32(f->inocache->ino); 151 ri.version = cpu_to_je32(++f->highest_version); 152 ri.mode = cpu_to_jemode(inode->i_mode); 153 ri.uid = cpu_to_je16(inode->i_uid); 154 ri.gid = cpu_to_je16(inode->i_gid); 155 ri.isize = cpu_to_je32(max((uint32_t)inode->i_size, pageofs)); 156 ri.atime = ri.ctime = ri.mtime = cpu_to_je32(get_seconds()); 157 ri.offset = cpu_to_je32(inode->i_size); 158 ri.dsize = cpu_to_je32(pageofs - inode->i_size); 159 ri.csize = cpu_to_je32(0); 160 ri.compr = JFFS2_COMPR_ZERO; 161 ri.node_crc = cpu_to_je32(crc32(0, &ri, sizeof(ri)-8)); 162 ri.data_crc = cpu_to_je32(0); 163 164 fn = jffs2_write_dnode(c, f, &ri, NULL, 0, phys_ofs, ALLOC_NORMAL); 165 166 if (IS_ERR(fn)) { 167 ret = PTR_ERR(fn); 168 jffs2_complete_reservation(c); 169 up(&f->sem); 170 return ret; 171 } 172 ret = jffs2_add_full_dnode_to_inode(c, f, fn); 173 if (f->metadata) { 174 jffs2_mark_node_obsolete(c, f->metadata->raw); 175 jffs2_free_full_dnode(f->metadata); 176 f->metadata = NULL; 177 } 178 if (ret) { 179 D1(printk(KERN_DEBUG "Eep. add_full_dnode_to_inode() failed in prepare_write, returned %d\n", ret)); 180 jffs2_mark_node_obsolete(c, fn->raw); 181 jffs2_free_full_dnode(fn); 182 jffs2_complete_reservation(c); 183 up(&f->sem); 184 return ret; 185 } 186 jffs2_complete_reservation(c); 187 inode->i_size = pageofs; 188 up(&f->sem); 189 } 190 191 /* Read in the page if it wasn't already present, unless it's a whole page */ 192 if (!PageUptodate(pg) && (start || end < PAGE_CACHE_SIZE)) { 193 down(&f->sem); 194 ret = jffs2_do_readpage_nolock(inode, pg); 195 up(&f->sem); 196 } 197 D1(printk(KERN_DEBUG "end prepare_write(). pg->flags %lx\n", pg->flags)); 198 return ret; 199 } 200 201 static int jffs2_commit_write (struct file *filp, struct page *pg, 202 unsigned start, unsigned end) 203 { 204 /* Actually commit the write from the page cache page we're looking at. 205 * For now, we write the full page out each time. It sucks, but it's simple 206 */ 207 struct inode *inode = pg->mapping->host; 208 struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode); 209 struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb); 210 struct jffs2_raw_inode *ri; 211 unsigned aligned_start = start & ~3; 212 int ret = 0; 213 uint32_t writtenlen = 0; 214 215 D1(printk(KERN_DEBUG "jffs2_commit_write(): ino #%lu, page at 0x%lx, range %d-%d, flags %lx\n", 216 inode->i_ino, pg->index << PAGE_CACHE_SHIFT, start, end, pg->flags)); 217 218 if (!start && end == PAGE_CACHE_SIZE) { 219 /* We need to avoid deadlock with page_cache_read() in 220 jffs2_garbage_collect_pass(). So we have to mark the 221 page up to date, to prevent page_cache_read() from 222 trying to re-lock it. */ 223 SetPageUptodate(pg); 224 } 225 226 ri = jffs2_alloc_raw_inode(); 227 228 if (!ri) { 229 D1(printk(KERN_DEBUG "jffs2_commit_write(): Allocation of raw inode failed\n")); 230 return -ENOMEM; 231 } 232 233 /* Set the fields that the generic jffs2_write_inode_range() code can't find */ 234 ri->ino = cpu_to_je32(inode->i_ino); 235 ri->mode = cpu_to_jemode(inode->i_mode); 236 ri->uid = cpu_to_je16(inode->i_uid); 237 ri->gid = cpu_to_je16(inode->i_gid); 238 ri->isize = cpu_to_je32((uint32_t)inode->i_size); 239 ri->atime = ri->ctime = ri->mtime = cpu_to_je32(get_seconds()); 240 241 /* In 2.4, it was already kmapped by generic_file_write(). Doesn't 242 hurt to do it again. The alternative is ifdefs, which are ugly. */ 243 kmap(pg); 244 245 ret = jffs2_write_inode_range(c, f, ri, page_address(pg) + aligned_start, 246 (pg->index << PAGE_CACHE_SHIFT) + aligned_start, 247 end - aligned_start, &writtenlen); 248 249 kunmap(pg); 250 251 if (ret) { 252 /* There was an error writing. */ 253 SetPageError(pg); 254 } 255 256 /* Adjust writtenlen for the padding we did, so we don't confuse our caller */ 257 if (writtenlen < (start&3)) 258 writtenlen = 0; 259 else 260 writtenlen -= (start&3); 261 262 if (writtenlen) { 263 if (inode->i_size < (pg->index << PAGE_CACHE_SHIFT) + start + writtenlen) { 264 inode->i_size = (pg->index << PAGE_CACHE_SHIFT) + start + writtenlen; 265 inode->i_blocks = (inode->i_size + 511) >> 9; 266 267 inode->i_ctime = inode->i_mtime = ITIME(je32_to_cpu(ri->ctime)); 268 } 269 } 270 271 jffs2_free_raw_inode(ri); 272 273 if (start+writtenlen < end) { 274 /* generic_file_write has written more to the page cache than we've 275 actually written to the medium. Mark the page !Uptodate so that 276 it gets reread */ 277 D1(printk(KERN_DEBUG "jffs2_commit_write(): Not all bytes written. Marking page !uptodate\n")); 278 SetPageError(pg); 279 ClearPageUptodate(pg); 280 } 281 282 D1(printk(KERN_DEBUG "jffs2_commit_write() returning %d\n",start+writtenlen==end?0:ret)); 283 return start+writtenlen==end?0:ret; 284 } 285