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 1.102 2005/07/06 12:13:09 dwmw2 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 extern int generic_file_open(struct inode *, struct file *) __attribute__((weak)); 25 extern loff_t generic_file_llseek(struct file *file, loff_t offset, int origin) __attribute__((weak)); 26 27 static int jffs2_commit_write (struct file *filp, struct page *pg, 28 unsigned start, unsigned end); 29 static int jffs2_prepare_write (struct file *filp, struct page *pg, 30 unsigned start, unsigned end); 31 static int jffs2_readpage (struct file *filp, struct page *pg); 32 33 int jffs2_fsync(struct file *filp, struct dentry *dentry, int datasync) 34 { 35 struct inode *inode = dentry->d_inode; 36 struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb); 37 38 /* Trigger GC to flush any pending writes for this inode */ 39 jffs2_flush_wbuf_gc(c, inode->i_ino); 40 41 return 0; 42 } 43 44 struct file_operations jffs2_file_operations = 45 { 46 .llseek = generic_file_llseek, 47 .open = generic_file_open, 48 .read = generic_file_read, 49 .write = generic_file_write, 50 .ioctl = jffs2_ioctl, 51 .mmap = generic_file_readonly_mmap, 52 .fsync = jffs2_fsync, 53 .sendfile = generic_file_sendfile 54 }; 55 56 /* jffs2_file_inode_operations */ 57 58 struct inode_operations jffs2_file_inode_operations = 59 { 60 .setattr = jffs2_setattr 61 }; 62 63 struct address_space_operations jffs2_file_address_operations = 64 { 65 .readpage = jffs2_readpage, 66 .prepare_write =jffs2_prepare_write, 67 .commit_write = jffs2_commit_write 68 }; 69 70 static int jffs2_do_readpage_nolock (struct inode *inode, struct page *pg) 71 { 72 struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode); 73 struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb); 74 unsigned char *pg_buf; 75 int ret; 76 77 D2(printk(KERN_DEBUG "jffs2_do_readpage_nolock(): ino #%lu, page at offset 0x%lx\n", inode->i_ino, pg->index << PAGE_CACHE_SHIFT)); 78 79 BUG_ON(!PageLocked(pg)); 80 81 pg_buf = kmap(pg); 82 /* FIXME: Can kmap fail? */ 83 84 ret = jffs2_read_inode_range(c, f, pg_buf, pg->index << PAGE_CACHE_SHIFT, PAGE_CACHE_SIZE); 85 86 if (ret) { 87 ClearPageUptodate(pg); 88 SetPageError(pg); 89 } else { 90 SetPageUptodate(pg); 91 ClearPageError(pg); 92 } 93 94 flush_dcache_page(pg); 95 kunmap(pg); 96 97 D2(printk(KERN_DEBUG "readpage finished\n")); 98 return 0; 99 } 100 101 int jffs2_do_readpage_unlock(struct inode *inode, struct page *pg) 102 { 103 int ret = jffs2_do_readpage_nolock(inode, pg); 104 unlock_page(pg); 105 return ret; 106 } 107 108 109 static int jffs2_readpage (struct file *filp, struct page *pg) 110 { 111 struct jffs2_inode_info *f = JFFS2_INODE_INFO(pg->mapping->host); 112 int ret; 113 114 down(&f->sem); 115 ret = jffs2_do_readpage_unlock(pg->mapping->host, pg); 116 up(&f->sem); 117 return ret; 118 } 119 120 static int jffs2_prepare_write (struct file *filp, struct page *pg, 121 unsigned start, unsigned end) 122 { 123 struct inode *inode = pg->mapping->host; 124 struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode); 125 uint32_t pageofs = pg->index << PAGE_CACHE_SHIFT; 126 int ret = 0; 127 128 D1(printk(KERN_DEBUG "jffs2_prepare_write()\n")); 129 130 if (pageofs > inode->i_size) { 131 /* Make new hole frag from old EOF to new page */ 132 struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb); 133 struct jffs2_raw_inode ri; 134 struct jffs2_full_dnode *fn; 135 uint32_t phys_ofs, alloc_len; 136 137 D1(printk(KERN_DEBUG "Writing new hole frag 0x%x-0x%x between current EOF and new page\n", 138 (unsigned int)inode->i_size, pageofs)); 139 140 ret = jffs2_reserve_space(c, sizeof(ri), &phys_ofs, &alloc_len, ALLOC_NORMAL); 141 if (ret) 142 return ret; 143 144 down(&f->sem); 145 memset(&ri, 0, sizeof(ri)); 146 147 ri.magic = cpu_to_je16(JFFS2_MAGIC_BITMASK); 148 ri.nodetype = cpu_to_je16(JFFS2_NODETYPE_INODE); 149 ri.totlen = cpu_to_je32(sizeof(ri)); 150 ri.hdr_crc = cpu_to_je32(crc32(0, &ri, sizeof(struct jffs2_unknown_node)-4)); 151 152 ri.ino = cpu_to_je32(f->inocache->ino); 153 ri.version = cpu_to_je32(++f->highest_version); 154 ri.mode = cpu_to_jemode(inode->i_mode); 155 ri.uid = cpu_to_je16(inode->i_uid); 156 ri.gid = cpu_to_je16(inode->i_gid); 157 ri.isize = cpu_to_je32(max((uint32_t)inode->i_size, pageofs)); 158 ri.atime = ri.ctime = ri.mtime = cpu_to_je32(get_seconds()); 159 ri.offset = cpu_to_je32(inode->i_size); 160 ri.dsize = cpu_to_je32(pageofs - inode->i_size); 161 ri.csize = cpu_to_je32(0); 162 ri.compr = JFFS2_COMPR_ZERO; 163 ri.node_crc = cpu_to_je32(crc32(0, &ri, sizeof(ri)-8)); 164 ri.data_crc = cpu_to_je32(0); 165 166 fn = jffs2_write_dnode(c, f, &ri, NULL, 0, phys_ofs, ALLOC_NORMAL); 167 168 if (IS_ERR(fn)) { 169 ret = PTR_ERR(fn); 170 jffs2_complete_reservation(c); 171 up(&f->sem); 172 return ret; 173 } 174 ret = jffs2_add_full_dnode_to_inode(c, f, fn); 175 if (f->metadata) { 176 jffs2_mark_node_obsolete(c, f->metadata->raw); 177 jffs2_free_full_dnode(f->metadata); 178 f->metadata = NULL; 179 } 180 if (ret) { 181 D1(printk(KERN_DEBUG "Eep. add_full_dnode_to_inode() failed in prepare_write, returned %d\n", ret)); 182 jffs2_mark_node_obsolete(c, fn->raw); 183 jffs2_free_full_dnode(fn); 184 jffs2_complete_reservation(c); 185 up(&f->sem); 186 return ret; 187 } 188 jffs2_complete_reservation(c); 189 inode->i_size = pageofs; 190 up(&f->sem); 191 } 192 193 /* Read in the page if it wasn't already present, unless it's a whole page */ 194 if (!PageUptodate(pg) && (start || end < PAGE_CACHE_SIZE)) { 195 down(&f->sem); 196 ret = jffs2_do_readpage_nolock(inode, pg); 197 up(&f->sem); 198 } 199 D1(printk(KERN_DEBUG "end prepare_write(). pg->flags %lx\n", pg->flags)); 200 return ret; 201 } 202 203 static int jffs2_commit_write (struct file *filp, struct page *pg, 204 unsigned start, unsigned end) 205 { 206 /* Actually commit the write from the page cache page we're looking at. 207 * For now, we write the full page out each time. It sucks, but it's simple 208 */ 209 struct inode *inode = pg->mapping->host; 210 struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode); 211 struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb); 212 struct jffs2_raw_inode *ri; 213 unsigned aligned_start = start & ~3; 214 int ret = 0; 215 uint32_t writtenlen = 0; 216 217 D1(printk(KERN_DEBUG "jffs2_commit_write(): ino #%lu, page at 0x%lx, range %d-%d, flags %lx\n", 218 inode->i_ino, pg->index << PAGE_CACHE_SHIFT, start, end, pg->flags)); 219 220 if (!start && end == PAGE_CACHE_SIZE) { 221 /* We need to avoid deadlock with page_cache_read() in 222 jffs2_garbage_collect_pass(). So we have to mark the 223 page up to date, to prevent page_cache_read() from 224 trying to re-lock it. */ 225 SetPageUptodate(pg); 226 } 227 228 ri = jffs2_alloc_raw_inode(); 229 230 if (!ri) { 231 D1(printk(KERN_DEBUG "jffs2_commit_write(): Allocation of raw inode failed\n")); 232 return -ENOMEM; 233 } 234 235 /* Set the fields that the generic jffs2_write_inode_range() code can't find */ 236 ri->ino = cpu_to_je32(inode->i_ino); 237 ri->mode = cpu_to_jemode(inode->i_mode); 238 ri->uid = cpu_to_je16(inode->i_uid); 239 ri->gid = cpu_to_je16(inode->i_gid); 240 ri->isize = cpu_to_je32((uint32_t)inode->i_size); 241 ri->atime = ri->ctime = ri->mtime = cpu_to_je32(get_seconds()); 242 243 /* In 2.4, it was already kmapped by generic_file_write(). Doesn't 244 hurt to do it again. The alternative is ifdefs, which are ugly. */ 245 kmap(pg); 246 247 ret = jffs2_write_inode_range(c, f, ri, page_address(pg) + aligned_start, 248 (pg->index << PAGE_CACHE_SHIFT) + aligned_start, 249 end - aligned_start, &writtenlen); 250 251 kunmap(pg); 252 253 if (ret) { 254 /* There was an error writing. */ 255 SetPageError(pg); 256 } 257 258 /* Adjust writtenlen for the padding we did, so we don't confuse our caller */ 259 if (writtenlen < (start&3)) 260 writtenlen = 0; 261 else 262 writtenlen -= (start&3); 263 264 if (writtenlen) { 265 if (inode->i_size < (pg->index << PAGE_CACHE_SHIFT) + start + writtenlen) { 266 inode->i_size = (pg->index << PAGE_CACHE_SHIFT) + start + writtenlen; 267 inode->i_blocks = (inode->i_size + 511) >> 9; 268 269 inode->i_ctime = inode->i_mtime = ITIME(je32_to_cpu(ri->ctime)); 270 } 271 } 272 273 jffs2_free_raw_inode(ri); 274 275 if (start+writtenlen < end) { 276 /* generic_file_write has written more to the page cache than we've 277 actually written to the medium. Mark the page !Uptodate so that 278 it gets reread */ 279 D1(printk(KERN_DEBUG "jffs2_commit_write(): Not all bytes written. Marking page !uptodate\n")); 280 SetPageError(pg); 281 ClearPageUptodate(pg); 282 } 283 284 D1(printk(KERN_DEBUG "jffs2_commit_write() returning %d\n",writtenlen?writtenlen:ret)); 285 return writtenlen?writtenlen:ret; 286 } 287