Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (c) 2000-2001 Christoph Hellwig. |
| 3 | * All rights reserved. |
| 4 | * |
| 5 | * Redistribution and use in source and binary forms, with or without |
| 6 | * modification, are permitted provided that the following conditions |
| 7 | * are met: |
| 8 | * 1. Redistributions of source code must retain the above copyright |
| 9 | * notice, this list of conditions, and the following disclaimer, |
| 10 | * without modification. |
| 11 | * 2. The name of the author may not be used to endorse or promote products |
| 12 | * derived from this software without specific prior written permission. |
| 13 | * |
| 14 | * Alternatively, this software may be distributed under the terms of the |
| 15 | * GNU General Public License ("GPL"). |
| 16 | * |
| 17 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND |
| 18 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 19 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 20 | * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR |
| 21 | * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| 22 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| 23 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 24 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| 25 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| 26 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 27 | * SUCH DAMAGE. |
| 28 | */ |
| 29 | |
| 30 | /* |
| 31 | * Veritas filesystem driver - lookup and other directory related code. |
| 32 | */ |
| 33 | #include <linux/fs.h> |
| 34 | #include <linux/time.h> |
| 35 | #include <linux/mm.h> |
| 36 | #include <linux/highmem.h> |
| 37 | #include <linux/kernel.h> |
| 38 | #include <linux/pagemap.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 39 | |
| 40 | #include "vxfs.h" |
| 41 | #include "vxfs_dir.h" |
| 42 | #include "vxfs_inode.h" |
| 43 | #include "vxfs_extern.h" |
| 44 | |
| 45 | /* |
| 46 | * Number of VxFS blocks per page. |
| 47 | */ |
| 48 | #define VXFS_BLOCK_PER_PAGE(sbp) ((PAGE_CACHE_SIZE / (sbp)->s_blocksize)) |
| 49 | |
| 50 | |
Al Viro | 00cd8dd | 2012-06-10 17:13:09 -0400 | [diff] [blame] | 51 | static struct dentry * vxfs_lookup(struct inode *, struct dentry *, unsigned int); |
Al Viro | 9b5d5a1 | 2013-05-18 03:15:00 -0400 | [diff] [blame] | 52 | static int vxfs_readdir(struct file *, struct dir_context *); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 53 | |
Arjan van de Ven | 754661f | 2007-02-12 00:55:38 -0800 | [diff] [blame] | 54 | const struct inode_operations vxfs_dir_inode_ops = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 55 | .lookup = vxfs_lookup, |
| 56 | }; |
| 57 | |
Arjan van de Ven | 4b6f5d2 | 2006-03-28 01:56:42 -0800 | [diff] [blame] | 58 | const struct file_operations vxfs_dir_operations = { |
jan Blunck | ca57272 | 2010-05-26 14:44:53 -0700 | [diff] [blame] | 59 | .llseek = generic_file_llseek, |
| 60 | .read = generic_read_dir, |
Al Viro | 9b5d5a1 | 2013-05-18 03:15:00 -0400 | [diff] [blame] | 61 | .iterate = vxfs_readdir, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 62 | }; |
| 63 | |
| 64 | |
Pekka Enberg | 8cb681b | 2005-06-30 02:59:05 -0700 | [diff] [blame] | 65 | static inline u_long |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 66 | dir_pages(struct inode *inode) |
| 67 | { |
| 68 | return (inode->i_size + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; |
| 69 | } |
| 70 | |
Pekka Enberg | 8cb681b | 2005-06-30 02:59:05 -0700 | [diff] [blame] | 71 | static inline u_long |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 72 | dir_blocks(struct inode *ip) |
| 73 | { |
| 74 | u_long bsize = ip->i_sb->s_blocksize; |
| 75 | return (ip->i_size + bsize - 1) & ~(bsize - 1); |
| 76 | } |
| 77 | |
| 78 | /* |
| 79 | * NOTE! unlike strncmp, vxfs_match returns 1 for success, 0 for failure. |
| 80 | * |
| 81 | * len <= VXFS_NAMELEN and de != NULL are guaranteed by caller. |
| 82 | */ |
Pekka Enberg | 8cb681b | 2005-06-30 02:59:05 -0700 | [diff] [blame] | 83 | static inline int |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 84 | vxfs_match(int len, const char * const name, struct vxfs_direct *de) |
| 85 | { |
| 86 | if (len != de->d_namelen) |
| 87 | return 0; |
| 88 | if (!de->d_ino) |
| 89 | return 0; |
| 90 | return !memcmp(name, de->d_name, len); |
| 91 | } |
| 92 | |
Pekka Enberg | 8cb681b | 2005-06-30 02:59:05 -0700 | [diff] [blame] | 93 | static inline struct vxfs_direct * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 94 | vxfs_next_entry(struct vxfs_direct *de) |
| 95 | { |
| 96 | return ((struct vxfs_direct *)((char*)de + de->d_reclen)); |
| 97 | } |
| 98 | |
| 99 | /** |
| 100 | * vxfs_find_entry - find a mathing directory entry for a dentry |
| 101 | * @ip: directory inode |
| 102 | * @dp: dentry for which we want to find a direct |
| 103 | * @ppp: gets filled with the page the return value sits in |
| 104 | * |
| 105 | * Description: |
| 106 | * vxfs_find_entry finds a &struct vxfs_direct for the VFS directory |
| 107 | * cache entry @dp. @ppp will be filled with the page the return |
| 108 | * value resides in. |
| 109 | * |
| 110 | * Returns: |
| 111 | * The wanted direct on success, else a NULL pointer. |
| 112 | */ |
| 113 | static struct vxfs_direct * |
| 114 | vxfs_find_entry(struct inode *ip, struct dentry *dp, struct page **ppp) |
| 115 | { |
| 116 | u_long npages, page, nblocks, pblocks, block; |
| 117 | u_long bsize = ip->i_sb->s_blocksize; |
| 118 | const char *name = dp->d_name.name; |
| 119 | int namelen = dp->d_name.len; |
| 120 | |
| 121 | npages = dir_pages(ip); |
| 122 | nblocks = dir_blocks(ip); |
| 123 | pblocks = VXFS_BLOCK_PER_PAGE(ip->i_sb); |
| 124 | |
| 125 | for (page = 0; page < npages; page++) { |
| 126 | caddr_t kaddr; |
| 127 | struct page *pp; |
| 128 | |
| 129 | pp = vxfs_get_page(ip->i_mapping, page); |
| 130 | if (IS_ERR(pp)) |
| 131 | continue; |
| 132 | kaddr = (caddr_t)page_address(pp); |
| 133 | |
| 134 | for (block = 0; block <= nblocks && block <= pblocks; block++) { |
| 135 | caddr_t baddr, limit; |
| 136 | struct vxfs_dirblk *dbp; |
| 137 | struct vxfs_direct *de; |
| 138 | |
| 139 | baddr = kaddr + (block * bsize); |
| 140 | limit = baddr + bsize - VXFS_DIRLEN(1); |
| 141 | |
| 142 | dbp = (struct vxfs_dirblk *)baddr; |
| 143 | de = (struct vxfs_direct *)(baddr + VXFS_DIRBLKOV(dbp)); |
| 144 | |
| 145 | for (; (caddr_t)de <= limit; de = vxfs_next_entry(de)) { |
| 146 | if (!de->d_reclen) |
| 147 | break; |
| 148 | if (!de->d_ino) |
| 149 | continue; |
| 150 | if (vxfs_match(namelen, name, de)) { |
| 151 | *ppp = pp; |
| 152 | return (de); |
| 153 | } |
| 154 | } |
| 155 | } |
| 156 | vxfs_put_page(pp); |
| 157 | } |
| 158 | |
| 159 | return NULL; |
| 160 | } |
| 161 | |
| 162 | /** |
| 163 | * vxfs_inode_by_name - find inode number for dentry |
| 164 | * @dip: directory to search in |
Lucas De Marchi | 25985ed | 2011-03-30 22:57:33 -0300 | [diff] [blame] | 165 | * @dp: dentry we search for |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 166 | * |
| 167 | * Description: |
| 168 | * vxfs_inode_by_name finds out the inode number of |
| 169 | * the path component described by @dp in @dip. |
| 170 | * |
| 171 | * Returns: |
| 172 | * The wanted inode number on success, else Zero. |
| 173 | */ |
| 174 | static ino_t |
| 175 | vxfs_inode_by_name(struct inode *dip, struct dentry *dp) |
| 176 | { |
| 177 | struct vxfs_direct *de; |
| 178 | struct page *pp; |
| 179 | ino_t ino = 0; |
| 180 | |
| 181 | de = vxfs_find_entry(dip, dp, &pp); |
| 182 | if (de) { |
| 183 | ino = de->d_ino; |
| 184 | kunmap(pp); |
| 185 | page_cache_release(pp); |
| 186 | } |
| 187 | |
| 188 | return (ino); |
| 189 | } |
| 190 | |
| 191 | /** |
| 192 | * vxfs_lookup - lookup pathname component |
| 193 | * @dip: dir in which we lookup |
| 194 | * @dp: dentry we lookup |
| 195 | * @nd: lookup nameidata |
| 196 | * |
| 197 | * Description: |
| 198 | * vxfs_lookup tries to lookup the pathname component described |
| 199 | * by @dp in @dip. |
| 200 | * |
| 201 | * Returns: |
| 202 | * A NULL-pointer on success, else an negative error code encoded |
| 203 | * in the return pointer. |
| 204 | */ |
| 205 | static struct dentry * |
Al Viro | 00cd8dd | 2012-06-10 17:13:09 -0400 | [diff] [blame] | 206 | vxfs_lookup(struct inode *dip, struct dentry *dp, unsigned int flags) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 207 | { |
| 208 | struct inode *ip = NULL; |
| 209 | ino_t ino; |
| 210 | |
| 211 | if (dp->d_name.len > VXFS_NAMELEN) |
| 212 | return ERR_PTR(-ENAMETOOLONG); |
| 213 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 214 | ino = vxfs_inode_by_name(dip, dp); |
| 215 | if (ino) { |
David Howells | d0b0794 | 2008-02-07 00:15:39 -0800 | [diff] [blame] | 216 | ip = vxfs_iget(dip->i_sb, ino); |
Arnd Bergmann | 6d7bccc | 2010-10-21 15:58:01 +0200 | [diff] [blame] | 217 | if (IS_ERR(ip)) |
David Howells | d0b0794 | 2008-02-07 00:15:39 -0800 | [diff] [blame] | 218 | return ERR_CAST(ip); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 219 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 220 | d_add(dp, ip); |
| 221 | return NULL; |
| 222 | } |
| 223 | |
| 224 | /** |
| 225 | * vxfs_readdir - read a directory |
| 226 | * @fp: the directory to read |
| 227 | * @retp: return buffer |
| 228 | * @filler: filldir callback |
| 229 | * |
| 230 | * Description: |
| 231 | * vxfs_readdir fills @retp with directory entries from @fp |
| 232 | * using the VFS supplied callback @filler. |
| 233 | * |
| 234 | * Returns: |
| 235 | * Zero. |
| 236 | */ |
| 237 | static int |
Al Viro | 9b5d5a1 | 2013-05-18 03:15:00 -0400 | [diff] [blame] | 238 | vxfs_readdir(struct file *fp, struct dir_context *ctx) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 239 | { |
Al Viro | 496ad9a | 2013-01-23 17:07:38 -0500 | [diff] [blame] | 240 | struct inode *ip = file_inode(fp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 241 | struct super_block *sbp = ip->i_sb; |
| 242 | u_long bsize = sbp->s_blocksize; |
| 243 | u_long page, npages, block, pblocks, nblocks, offset; |
| 244 | loff_t pos; |
| 245 | |
Al Viro | 9b5d5a1 | 2013-05-18 03:15:00 -0400 | [diff] [blame] | 246 | if (ctx->pos == 0) { |
| 247 | if (!dir_emit_dot(fp, ctx)) |
| 248 | return 0; |
| 249 | ctx->pos = 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 250 | } |
Al Viro | 9b5d5a1 | 2013-05-18 03:15:00 -0400 | [diff] [blame] | 251 | if (ctx->pos == 1) { |
| 252 | if (!dir_emit(ctx, "..", 2, VXFS_INO(ip)->vii_dotdot, DT_DIR)) |
| 253 | return 0; |
| 254 | ctx->pos = 2; |
| 255 | } |
| 256 | pos = ctx->pos - 2; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 257 | |
Arnd Bergmann | 6d7bccc | 2010-10-21 15:58:01 +0200 | [diff] [blame] | 258 | if (pos > VXFS_DIRROUND(ip->i_size)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 259 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 260 | |
| 261 | npages = dir_pages(ip); |
| 262 | nblocks = dir_blocks(ip); |
| 263 | pblocks = VXFS_BLOCK_PER_PAGE(sbp); |
| 264 | |
| 265 | page = pos >> PAGE_CACHE_SHIFT; |
| 266 | offset = pos & ~PAGE_CACHE_MASK; |
| 267 | block = (u_long)(pos >> sbp->s_blocksize_bits) % pblocks; |
| 268 | |
| 269 | for (; page < npages; page++, block = 0) { |
Al Viro | 9b5d5a1 | 2013-05-18 03:15:00 -0400 | [diff] [blame] | 270 | char *kaddr; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 271 | struct page *pp; |
| 272 | |
| 273 | pp = vxfs_get_page(ip->i_mapping, page); |
| 274 | if (IS_ERR(pp)) |
| 275 | continue; |
Al Viro | 9b5d5a1 | 2013-05-18 03:15:00 -0400 | [diff] [blame] | 276 | kaddr = (char *)page_address(pp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 277 | |
| 278 | for (; block <= nblocks && block <= pblocks; block++) { |
Al Viro | 9b5d5a1 | 2013-05-18 03:15:00 -0400 | [diff] [blame] | 279 | char *baddr, *limit; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 280 | struct vxfs_dirblk *dbp; |
| 281 | struct vxfs_direct *de; |
| 282 | |
| 283 | baddr = kaddr + (block * bsize); |
| 284 | limit = baddr + bsize - VXFS_DIRLEN(1); |
| 285 | |
| 286 | dbp = (struct vxfs_dirblk *)baddr; |
| 287 | de = (struct vxfs_direct *) |
| 288 | (offset ? |
| 289 | (kaddr + offset) : |
| 290 | (baddr + VXFS_DIRBLKOV(dbp))); |
| 291 | |
Al Viro | 9b5d5a1 | 2013-05-18 03:15:00 -0400 | [diff] [blame] | 292 | for (; (char *)de <= limit; de = vxfs_next_entry(de)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 293 | if (!de->d_reclen) |
| 294 | break; |
| 295 | if (!de->d_ino) |
| 296 | continue; |
| 297 | |
Al Viro | 9b5d5a1 | 2013-05-18 03:15:00 -0400 | [diff] [blame] | 298 | offset = (char *)de - kaddr; |
| 299 | ctx->pos = ((page << PAGE_CACHE_SHIFT) | offset) + 2; |
| 300 | if (!dir_emit(ctx, de->d_name, de->d_namelen, |
| 301 | de->d_ino, DT_UNKNOWN)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 302 | vxfs_put_page(pp); |
Al Viro | 9b5d5a1 | 2013-05-18 03:15:00 -0400 | [diff] [blame] | 303 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 304 | } |
| 305 | } |
| 306 | offset = 0; |
| 307 | } |
| 308 | vxfs_put_page(pp); |
| 309 | offset = 0; |
| 310 | } |
Al Viro | 9b5d5a1 | 2013-05-18 03:15:00 -0400 | [diff] [blame] | 311 | ctx->pos = ((page << PAGE_CACHE_SHIFT) | offset) + 2; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 312 | return 0; |
| 313 | } |