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 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, ALLOC_NORMAL); 138 if (ret) 139 return ret; 140 141 down(&f->sem); 142 memset(&ri, 0, sizeof(ri)); 143 144 ri.magic = cpu_to_je16(JFFS2_MAGIC_BITMASK); 145 ri.nodetype = cpu_to_je16(JFFS2_NODETYPE_INODE); 146 ri.totlen = cpu_to_je32(sizeof(ri)); 147 ri.hdr_crc = cpu_to_je32(crc32(0, &ri, sizeof(struct jffs2_unknown_node)-4)); 148 149 ri.ino = cpu_to_je32(f->inocache->ino); 150 ri.version = cpu_to_je32(++f->highest_version); 151 ri.mode = cpu_to_jemode(inode->i_mode); 152 ri.uid = cpu_to_je16(inode->i_uid); 153 ri.gid = cpu_to_je16(inode->i_gid); 154 ri.isize = cpu_to_je32(max((uint32_t)inode->i_size, pageofs)); 155 ri.atime = ri.ctime = ri.mtime = cpu_to_je32(get_seconds()); 156 ri.offset = cpu_to_je32(inode->i_size); 157 ri.dsize = cpu_to_je32(pageofs - inode->i_size); 158 ri.csize = cpu_to_je32(0); 159 ri.compr = JFFS2_COMPR_ZERO; 160 ri.node_crc = cpu_to_je32(crc32(0, &ri, sizeof(ri)-8)); 161 ri.data_crc = cpu_to_je32(0); 162 163 fn = jffs2_write_dnode(c, f, &ri, NULL, 0, phys_ofs, ALLOC_NORMAL); 164 165 if (IS_ERR(fn)) { 166 ret = PTR_ERR(fn); 167 jffs2_complete_reservation(c); 168 up(&f->sem); 169 return ret; 170 } 171 ret = jffs2_add_full_dnode_to_inode(c, f, fn); 172 if (f->metadata) { 173 jffs2_mark_node_obsolete(c, f->metadata->raw); 174 jffs2_free_full_dnode(f->metadata); 175 f->metadata = NULL; 176 } 177 if (ret) { 178 D1(printk(KERN_DEBUG "Eep. add_full_dnode_to_inode() failed in prepare_write, returned %d\n", ret)); 179 jffs2_mark_node_obsolete(c, fn->raw); 180 jffs2_free_full_dnode(fn); 181 jffs2_complete_reservation(c); 182 up(&f->sem); 183 return ret; 184 } 185 jffs2_complete_reservation(c); 186 inode->i_size = pageofs; 187 up(&f->sem); 188 } 189 190 /* Read in the page if it wasn't already present, unless it's a whole page */ 191 if (!PageUptodate(pg) && (start || end < PAGE_CACHE_SIZE)) { 192 down(&f->sem); 193 ret = jffs2_do_readpage_nolock(inode, pg); 194 up(&f->sem); 195 } 196 D1(printk(KERN_DEBUG "end prepare_write(). pg->flags %lx\n", pg->flags)); 197 return ret; 198 } 199 200 static int jffs2_commit_write (struct file *filp, struct page *pg, 201 unsigned start, unsigned end) 202 { 203 /* Actually commit the write from the page cache page we're looking at. 204 * For now, we write the full page out each time. It sucks, but it's simple 205 */ 206 struct inode *inode = pg->mapping->host; 207 struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode); 208 struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb); 209 struct jffs2_raw_inode *ri; 210 unsigned aligned_start = start & ~3; 211 int ret = 0; 212 uint32_t writtenlen = 0; 213 214 D1(printk(KERN_DEBUG "jffs2_commit_write(): ino #%lu, page at 0x%lx, range %d-%d, flags %lx\n", 215 inode->i_ino, pg->index << PAGE_CACHE_SHIFT, start, end, pg->flags)); 216 217 if (!start && end == PAGE_CACHE_SIZE) { 218 /* We need to avoid deadlock with page_cache_read() in 219 jffs2_garbage_collect_pass(). So we have to mark the 220 page up to date, to prevent page_cache_read() from 221 trying to re-lock it. */ 222 SetPageUptodate(pg); 223 } 224 225 ri = jffs2_alloc_raw_inode(); 226 227 if (!ri) { 228 D1(printk(KERN_DEBUG "jffs2_commit_write(): Allocation of raw inode failed\n")); 229 return -ENOMEM; 230 } 231 232 /* Set the fields that the generic jffs2_write_inode_range() code can't find */ 233 ri->ino = cpu_to_je32(inode->i_ino); 234 ri->mode = cpu_to_jemode(inode->i_mode); 235 ri->uid = cpu_to_je16(inode->i_uid); 236 ri->gid = cpu_to_je16(inode->i_gid); 237 ri->isize = cpu_to_je32((uint32_t)inode->i_size); 238 ri->atime = ri->ctime = ri->mtime = cpu_to_je32(get_seconds()); 239 240 /* In 2.4, it was already kmapped by generic_file_write(). Doesn't 241 hurt to do it again. The alternative is ifdefs, which are ugly. */ 242 kmap(pg); 243 244 ret = jffs2_write_inode_range(c, f, ri, page_address(pg) + aligned_start, 245 (pg->index << PAGE_CACHE_SHIFT) + aligned_start, 246 end - aligned_start, &writtenlen); 247 248 kunmap(pg); 249 250 if (ret) { 251 /* There was an error writing. */ 252 SetPageError(pg); 253 } 254 255 /* Adjust writtenlen for the padding we did, so we don't confuse our caller */ 256 if (writtenlen < (start&3)) 257 writtenlen = 0; 258 else 259 writtenlen -= (start&3); 260 261 if (writtenlen) { 262 if (inode->i_size < (pg->index << PAGE_CACHE_SHIFT) + start + writtenlen) { 263 inode->i_size = (pg->index << PAGE_CACHE_SHIFT) + start + writtenlen; 264 inode->i_blocks = (inode->i_size + 511) >> 9; 265 266 inode->i_ctime = inode->i_mtime = ITIME(je32_to_cpu(ri->ctime)); 267 } 268 } 269 270 jffs2_free_raw_inode(ri); 271 272 if (start+writtenlen < end) { 273 /* generic_file_write has written more to the page cache than we've 274 actually written to the medium. Mark the page !Uptodate so that 275 it gets reread */ 276 D1(printk(KERN_DEBUG "jffs2_commit_write(): Not all bytes written. Marking page !uptodate\n")); 277 SetPageError(pg); 278 ClearPageUptodate(pg); 279 } 280 281 D1(printk(KERN_DEBUG "jffs2_commit_write() returning %d\n",writtenlen?writtenlen:ret)); 282 return writtenlen?writtenlen:ret; 283 } 284