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