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 1.99 2004/11/16 20:36:11 dwmw2 Exp $ 11 * 12 */ 13 14 #include <linux/version.h> 15 #include <linux/kernel.h> 16 #include <linux/slab.h> 17 #include <linux/fs.h> 18 #include <linux/time.h> 19 #include <linux/pagemap.h> 20 #include <linux/highmem.h> 21 #include <linux/crc32.h> 22 #include <linux/jffs2.h> 23 #include "nodelist.h" 24 25 extern int generic_file_open(struct inode *, struct file *) __attribute__((weak)); 26 extern loff_t generic_file_llseek(struct file *file, loff_t offset, int origin) __attribute__((weak)); 27 28 static int jffs2_commit_write (struct file *filp, struct page *pg, 29 unsigned start, unsigned end); 30 static int jffs2_prepare_write (struct file *filp, struct page *pg, 31 unsigned start, unsigned end); 32 static int jffs2_readpage (struct file *filp, struct page *pg); 33 34 int jffs2_fsync(struct file *filp, struct dentry *dentry, int datasync) 35 { 36 struct inode *inode = dentry->d_inode; 37 struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb); 38 39 /* Trigger GC to flush any pending writes for this inode */ 40 jffs2_flush_wbuf_gc(c, inode->i_ino); 41 42 return 0; 43 } 44 45 struct file_operations jffs2_file_operations = 46 { 47 .llseek = generic_file_llseek, 48 .open = generic_file_open, 49 .read = generic_file_read, 50 .write = generic_file_write, 51 .ioctl = jffs2_ioctl, 52 .mmap = generic_file_readonly_mmap, 53 .fsync = jffs2_fsync, 54 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,5,29) 55 .sendfile = generic_file_sendfile 56 #endif 57 }; 58 59 /* jffs2_file_inode_operations */ 60 61 struct inode_operations jffs2_file_inode_operations = 62 { 63 .setattr = jffs2_setattr 64 }; 65 66 struct address_space_operations jffs2_file_address_operations = 67 { 68 .readpage = jffs2_readpage, 69 .prepare_write =jffs2_prepare_write, 70 .commit_write = jffs2_commit_write 71 }; 72 73 static int jffs2_do_readpage_nolock (struct inode *inode, struct page *pg) 74 { 75 struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode); 76 struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb); 77 unsigned char *pg_buf; 78 int ret; 79 80 D2(printk(KERN_DEBUG "jffs2_do_readpage_nolock(): ino #%lu, page at offset 0x%lx\n", inode->i_ino, pg->index << PAGE_CACHE_SHIFT)); 81 82 if (!PageLocked(pg)) 83 PAGE_BUG(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 phys_ofs, 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), &phys_ofs, &alloc_len, ALLOC_NORMAL); 145 if (ret) 146 return ret; 147 148 down(&f->sem); 149 memset(&ri, 0, sizeof(ri)); 150 151 ri.magic = cpu_to_je16(JFFS2_MAGIC_BITMASK); 152 ri.nodetype = cpu_to_je16(JFFS2_NODETYPE_INODE); 153 ri.totlen = cpu_to_je32(sizeof(ri)); 154 ri.hdr_crc = cpu_to_je32(crc32(0, &ri, sizeof(struct jffs2_unknown_node)-4)); 155 156 ri.ino = cpu_to_je32(f->inocache->ino); 157 ri.version = cpu_to_je32(++f->highest_version); 158 ri.mode = cpu_to_jemode(inode->i_mode); 159 ri.uid = cpu_to_je16(inode->i_uid); 160 ri.gid = cpu_to_je16(inode->i_gid); 161 ri.isize = cpu_to_je32(max((uint32_t)inode->i_size, pageofs)); 162 ri.atime = ri.ctime = ri.mtime = cpu_to_je32(get_seconds()); 163 ri.offset = cpu_to_je32(inode->i_size); 164 ri.dsize = cpu_to_je32(pageofs - inode->i_size); 165 ri.csize = cpu_to_je32(0); 166 ri.compr = JFFS2_COMPR_ZERO; 167 ri.node_crc = cpu_to_je32(crc32(0, &ri, sizeof(ri)-8)); 168 ri.data_crc = cpu_to_je32(0); 169 170 fn = jffs2_write_dnode(c, f, &ri, NULL, 0, phys_ofs, ALLOC_NORMAL); 171 172 if (IS_ERR(fn)) { 173 ret = PTR_ERR(fn); 174 jffs2_complete_reservation(c); 175 up(&f->sem); 176 return ret; 177 } 178 ret = jffs2_add_full_dnode_to_inode(c, f, fn); 179 if (f->metadata) { 180 jffs2_mark_node_obsolete(c, f->metadata->raw); 181 jffs2_free_full_dnode(f->metadata); 182 f->metadata = NULL; 183 } 184 if (ret) { 185 D1(printk(KERN_DEBUG "Eep. add_full_dnode_to_inode() failed in prepare_write, returned %d\n", ret)); 186 jffs2_mark_node_obsolete(c, fn->raw); 187 jffs2_free_full_dnode(fn); 188 jffs2_complete_reservation(c); 189 up(&f->sem); 190 return ret; 191 } 192 jffs2_complete_reservation(c); 193 inode->i_size = pageofs; 194 up(&f->sem); 195 } 196 197 /* Read in the page if it wasn't already present, unless it's a whole page */ 198 if (!PageUptodate(pg) && (start || end < PAGE_CACHE_SIZE)) { 199 down(&f->sem); 200 ret = jffs2_do_readpage_nolock(inode, pg); 201 up(&f->sem); 202 } 203 D1(printk(KERN_DEBUG "end prepare_write(). pg->flags %lx\n", pg->flags)); 204 return ret; 205 } 206 207 static int jffs2_commit_write (struct file *filp, struct page *pg, 208 unsigned start, unsigned end) 209 { 210 /* Actually commit the write from the page cache page we're looking at. 211 * For now, we write the full page out each time. It sucks, but it's simple 212 */ 213 struct inode *inode = pg->mapping->host; 214 struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode); 215 struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb); 216 struct jffs2_raw_inode *ri; 217 unsigned aligned_start = start & ~3; 218 int ret = 0; 219 uint32_t writtenlen = 0; 220 221 D1(printk(KERN_DEBUG "jffs2_commit_write(): ino #%lu, page at 0x%lx, range %d-%d, flags %lx\n", 222 inode->i_ino, pg->index << PAGE_CACHE_SHIFT, start, end, pg->flags)); 223 224 if (!start && end == PAGE_CACHE_SIZE) { 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 } 231 232 ri = jffs2_alloc_raw_inode(); 233 234 if (!ri) { 235 D1(printk(KERN_DEBUG "jffs2_commit_write(): Allocation of raw inode failed\n")); 236 return -ENOMEM; 237 } 238 239 /* Set the fields that the generic jffs2_write_inode_range() code can't find */ 240 ri->ino = cpu_to_je32(inode->i_ino); 241 ri->mode = cpu_to_jemode(inode->i_mode); 242 ri->uid = cpu_to_je16(inode->i_uid); 243 ri->gid = cpu_to_je16(inode->i_gid); 244 ri->isize = cpu_to_je32((uint32_t)inode->i_size); 245 ri->atime = ri->ctime = ri->mtime = cpu_to_je32(get_seconds()); 246 247 /* In 2.4, it was already kmapped by generic_file_write(). Doesn't 248 hurt to do it again. The alternative is ifdefs, which are ugly. */ 249 kmap(pg); 250 251 ret = jffs2_write_inode_range(c, f, ri, page_address(pg) + aligned_start, 252 (pg->index << PAGE_CACHE_SHIFT) + aligned_start, 253 end - aligned_start, &writtenlen); 254 255 kunmap(pg); 256 257 if (ret) { 258 /* There was an error writing. */ 259 SetPageError(pg); 260 } 261 262 /* Adjust writtenlen for the padding we did, so we don't confuse our caller */ 263 if (writtenlen < (start&3)) 264 writtenlen = 0; 265 else 266 writtenlen -= (start&3); 267 268 if (writtenlen) { 269 if (inode->i_size < (pg->index << PAGE_CACHE_SHIFT) + start + writtenlen) { 270 inode->i_size = (pg->index << PAGE_CACHE_SHIFT) + start + writtenlen; 271 inode->i_blocks = (inode->i_size + 511) >> 9; 272 273 inode->i_ctime = inode->i_mtime = ITIME(je32_to_cpu(ri->ctime)); 274 } 275 } 276 277 jffs2_free_raw_inode(ri); 278 279 if (start+writtenlen < end) { 280 /* generic_file_write has written more to the page cache than we've 281 actually written to the medium. Mark the page !Uptodate so that 282 it gets reread */ 283 D1(printk(KERN_DEBUG "jffs2_commit_write(): Not all bytes written. Marking page !uptodate\n")); 284 SetPageError(pg); 285 ClearPageUptodate(pg); 286 } 287 288 D1(printk(KERN_DEBUG "jffs2_commit_write() returning %d\n",writtenlen?writtenlen:ret)); 289 return writtenlen?writtenlen:ret; 290 } 291