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 const struct file_operations jffs2_file_operations = 42 { 43 .llseek = generic_file_llseek, 44 .open = generic_file_open, 45 .read = do_sync_read, 46 .aio_read = generic_file_aio_read, 47 .write = do_sync_write, 48 .aio_write = generic_file_aio_write, 49 .ioctl = jffs2_ioctl, 50 .mmap = generic_file_readonly_mmap, 51 .fsync = jffs2_fsync, 52 .sendfile = generic_file_sendfile 53 }; 54 55 /* jffs2_file_inode_operations */ 56 57 const struct inode_operations jffs2_file_inode_operations = 58 { 59 .permission = jffs2_permission, 60 .setattr = jffs2_setattr, 61 .setxattr = jffs2_setxattr, 62 .getxattr = jffs2_getxattr, 63 .listxattr = jffs2_listxattr, 64 .removexattr = jffs2_removexattr 65 }; 66 67 const struct address_space_operations jffs2_file_address_operations = 68 { 69 .readpage = jffs2_readpage, 70 .prepare_write =jffs2_prepare_write, 71 .commit_write = jffs2_commit_write 72 }; 73 74 static int jffs2_do_readpage_nolock (struct inode *inode, struct page *pg) 75 { 76 struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode); 77 struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb); 78 unsigned char *pg_buf; 79 int ret; 80 81 D2(printk(KERN_DEBUG "jffs2_do_readpage_nolock(): ino #%lu, page at offset 0x%lx\n", inode->i_ino, pg->index << PAGE_CACHE_SHIFT)); 82 83 BUG_ON(!PageLocked(pg)); 84 85 pg_buf = kmap(pg); 86 /* FIXME: Can kmap fail? */ 87 88 ret = jffs2_read_inode_range(c, f, pg_buf, pg->index << PAGE_CACHE_SHIFT, PAGE_CACHE_SIZE); 89 90 if (ret) { 91 ClearPageUptodate(pg); 92 SetPageError(pg); 93 } else { 94 SetPageUptodate(pg); 95 ClearPageError(pg); 96 } 97 98 flush_dcache_page(pg); 99 kunmap(pg); 100 101 D2(printk(KERN_DEBUG "readpage finished\n")); 102 return 0; 103 } 104 105 int jffs2_do_readpage_unlock(struct inode *inode, struct page *pg) 106 { 107 int ret = jffs2_do_readpage_nolock(inode, pg); 108 unlock_page(pg); 109 return ret; 110 } 111 112 113 static int jffs2_readpage (struct file *filp, struct page *pg) 114 { 115 struct jffs2_inode_info *f = JFFS2_INODE_INFO(pg->mapping->host); 116 int ret; 117 118 down(&f->sem); 119 ret = jffs2_do_readpage_unlock(pg->mapping->host, pg); 120 up(&f->sem); 121 return ret; 122 } 123 124 static int jffs2_prepare_write (struct file *filp, struct page *pg, 125 unsigned start, unsigned end) 126 { 127 struct inode *inode = pg->mapping->host; 128 struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode); 129 uint32_t pageofs = pg->index << PAGE_CACHE_SHIFT; 130 int ret = 0; 131 132 D1(printk(KERN_DEBUG "jffs2_prepare_write()\n")); 133 134 if (pageofs > inode->i_size) { 135 /* Make new hole frag from old EOF to new page */ 136 struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb); 137 struct jffs2_raw_inode ri; 138 struct jffs2_full_dnode *fn; 139 uint32_t alloc_len; 140 141 D1(printk(KERN_DEBUG "Writing new hole frag 0x%x-0x%x between current EOF and new page\n", 142 (unsigned int)inode->i_size, pageofs)); 143 144 ret = jffs2_reserve_space(c, sizeof(ri), &alloc_len, 145 ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE); 146 if (ret) 147 return ret; 148 149 down(&f->sem); 150 memset(&ri, 0, sizeof(ri)); 151 152 ri.magic = cpu_to_je16(JFFS2_MAGIC_BITMASK); 153 ri.nodetype = cpu_to_je16(JFFS2_NODETYPE_INODE); 154 ri.totlen = cpu_to_je32(sizeof(ri)); 155 ri.hdr_crc = cpu_to_je32(crc32(0, &ri, sizeof(struct jffs2_unknown_node)-4)); 156 157 ri.ino = cpu_to_je32(f->inocache->ino); 158 ri.version = cpu_to_je32(++f->highest_version); 159 ri.mode = cpu_to_jemode(inode->i_mode); 160 ri.uid = cpu_to_je16(inode->i_uid); 161 ri.gid = cpu_to_je16(inode->i_gid); 162 ri.isize = cpu_to_je32(max((uint32_t)inode->i_size, pageofs)); 163 ri.atime = ri.ctime = ri.mtime = cpu_to_je32(get_seconds()); 164 ri.offset = cpu_to_je32(inode->i_size); 165 ri.dsize = cpu_to_je32(pageofs - inode->i_size); 166 ri.csize = cpu_to_je32(0); 167 ri.compr = JFFS2_COMPR_ZERO; 168 ri.node_crc = cpu_to_je32(crc32(0, &ri, sizeof(ri)-8)); 169 ri.data_crc = cpu_to_je32(0); 170 171 fn = jffs2_write_dnode(c, f, &ri, NULL, 0, ALLOC_NORMAL); 172 173 if (IS_ERR(fn)) { 174 ret = PTR_ERR(fn); 175 jffs2_complete_reservation(c); 176 up(&f->sem); 177 return ret; 178 } 179 ret = jffs2_add_full_dnode_to_inode(c, f, fn); 180 if (f->metadata) { 181 jffs2_mark_node_obsolete(c, f->metadata->raw); 182 jffs2_free_full_dnode(f->metadata); 183 f->metadata = NULL; 184 } 185 if (ret) { 186 D1(printk(KERN_DEBUG "Eep. add_full_dnode_to_inode() failed in prepare_write, returned %d\n", ret)); 187 jffs2_mark_node_obsolete(c, fn->raw); 188 jffs2_free_full_dnode(fn); 189 jffs2_complete_reservation(c); 190 up(&f->sem); 191 return ret; 192 } 193 jffs2_complete_reservation(c); 194 inode->i_size = pageofs; 195 up(&f->sem); 196 } 197 198 /* Read in the page if it wasn't already present, unless it's a whole page */ 199 if (!PageUptodate(pg) && (start || end < PAGE_CACHE_SIZE)) { 200 down(&f->sem); 201 ret = jffs2_do_readpage_nolock(inode, pg); 202 up(&f->sem); 203 } 204 D1(printk(KERN_DEBUG "end prepare_write(). pg->flags %lx\n", pg->flags)); 205 return ret; 206 } 207 208 static int jffs2_commit_write (struct file *filp, struct page *pg, 209 unsigned start, unsigned end) 210 { 211 /* Actually commit the write from the page cache page we're looking at. 212 * For now, we write the full page out each time. It sucks, but it's simple 213 */ 214 struct inode *inode = pg->mapping->host; 215 struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode); 216 struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb); 217 struct jffs2_raw_inode *ri; 218 unsigned aligned_start = start & ~3; 219 int ret = 0; 220 uint32_t writtenlen = 0; 221 222 D1(printk(KERN_DEBUG "jffs2_commit_write(): ino #%lu, page at 0x%lx, range %d-%d, flags %lx\n", 223 inode->i_ino, pg->index << PAGE_CACHE_SHIFT, start, end, pg->flags)); 224 225 if (end == PAGE_CACHE_SIZE) { 226 if (!start) { 227 /* We need to avoid deadlock with page_cache_read() in 228 jffs2_garbage_collect_pass(). So we have to mark the 229 page up to date, to prevent page_cache_read() from 230 trying to re-lock it. */ 231 SetPageUptodate(pg); 232 } else { 233 /* When writing out the end of a page, write out the 234 _whole_ page. This helps to reduce the number of 235 nodes in files which have many short writes, like 236 syslog files. */ 237 start = aligned_start = 0; 238 } 239 } 240 241 ri = jffs2_alloc_raw_inode(); 242 243 if (!ri) { 244 D1(printk(KERN_DEBUG "jffs2_commit_write(): Allocation of raw inode failed\n")); 245 return -ENOMEM; 246 } 247 248 /* Set the fields that the generic jffs2_write_inode_range() code can't find */ 249 ri->ino = cpu_to_je32(inode->i_ino); 250 ri->mode = cpu_to_jemode(inode->i_mode); 251 ri->uid = cpu_to_je16(inode->i_uid); 252 ri->gid = cpu_to_je16(inode->i_gid); 253 ri->isize = cpu_to_je32((uint32_t)inode->i_size); 254 ri->atime = ri->ctime = ri->mtime = cpu_to_je32(get_seconds()); 255 256 /* In 2.4, it was already kmapped by generic_file_write(). Doesn't 257 hurt to do it again. The alternative is ifdefs, which are ugly. */ 258 kmap(pg); 259 260 ret = jffs2_write_inode_range(c, f, ri, page_address(pg) + aligned_start, 261 (pg->index << PAGE_CACHE_SHIFT) + aligned_start, 262 end - aligned_start, &writtenlen); 263 264 kunmap(pg); 265 266 if (ret) { 267 /* There was an error writing. */ 268 SetPageError(pg); 269 } 270 271 /* Adjust writtenlen for the padding we did, so we don't confuse our caller */ 272 if (writtenlen < (start&3)) 273 writtenlen = 0; 274 else 275 writtenlen -= (start&3); 276 277 if (writtenlen) { 278 if (inode->i_size < (pg->index << PAGE_CACHE_SHIFT) + start + writtenlen) { 279 inode->i_size = (pg->index << PAGE_CACHE_SHIFT) + start + writtenlen; 280 inode->i_blocks = (inode->i_size + 511) >> 9; 281 282 inode->i_ctime = inode->i_mtime = ITIME(je32_to_cpu(ri->ctime)); 283 } 284 } 285 286 jffs2_free_raw_inode(ri); 287 288 if (start+writtenlen < end) { 289 /* generic_file_write has written more to the page cache than we've 290 actually written to the medium. Mark the page !Uptodate so that 291 it gets reread */ 292 D1(printk(KERN_DEBUG "jffs2_commit_write(): Not all bytes written. Marking page !uptodate\n")); 293 SetPageError(pg); 294 ClearPageUptodate(pg); 295 } 296 297 D1(printk(KERN_DEBUG "jffs2_commit_write() returning %d\n",start+writtenlen==end?0:ret)); 298 return start+writtenlen==end?0:ret; 299 } 300