2 * Copyright (c) 2000-2001 Christoph Hellwig.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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.
14 * Alternatively, this software may be distributed under the terms of the
15 * GNU General Public License ("GPL").
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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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
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22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * Veritas filesystem driver - lookup and other directory related code.
34 #include <linux/time.h>
36 #include <linux/highmem.h>
37 #include <linux/kernel.h>
38 #include <linux/pagemap.h>
42 #include "vxfs_inode.h"
43 #include "vxfs_extern.h"
46 * Number of VxFS blocks per page.
48 #define VXFS_BLOCK_PER_PAGE(sbp) ((PAGE_SIZE / (sbp)->s_blocksize))
51 static struct dentry * vxfs_lookup(struct inode *, struct dentry *, unsigned int);
52 static int vxfs_readdir(struct file *, struct dir_context *);
54 const struct inode_operations vxfs_dir_inode_ops = {
55 .lookup = vxfs_lookup,
58 const struct file_operations vxfs_dir_operations = {
59 .llseek = generic_file_llseek,
60 .read = generic_read_dir,
61 .iterate_shared = vxfs_readdir,
65 dir_blocks(struct inode *ip)
67 u_long bsize = ip->i_sb->s_blocksize;
68 return (ip->i_size + bsize - 1) & ~(bsize - 1);
72 * NOTE! unlike strncmp, vxfs_match returns 1 for success, 0 for failure.
74 * len <= VXFS_NAMELEN and de != NULL are guaranteed by caller.
77 vxfs_match(struct vxfs_sb_info *sbi, int len, const char *const name,
78 struct vxfs_direct *de)
80 if (len != fs16_to_cpu(sbi, de->d_namelen))
84 return !memcmp(name, de->d_name, len);
87 static inline struct vxfs_direct *
88 vxfs_next_entry(struct vxfs_sb_info *sbi, struct vxfs_direct *de)
90 return ((struct vxfs_direct *)
91 ((char *)de + fs16_to_cpu(sbi, de->d_reclen)));
95 * vxfs_find_entry - find a mathing directory entry for a dentry
96 * @ip: directory inode
97 * @dp: dentry for which we want to find a direct
98 * @ppp: gets filled with the page the return value sits in
101 * vxfs_find_entry finds a &struct vxfs_direct for the VFS directory
102 * cache entry @dp. @ppp will be filled with the page the return
106 * The wanted direct on success, else a NULL pointer.
108 static struct vxfs_direct *
109 vxfs_find_entry(struct inode *ip, struct dentry *dp, struct page **ppp)
111 struct vxfs_sb_info *sbi = VXFS_SBI(ip->i_sb);
112 u_long npages, page, nblocks, pblocks, block;
113 u_long bsize = ip->i_sb->s_blocksize;
114 const char *name = dp->d_name.name;
115 int namelen = dp->d_name.len;
117 npages = dir_pages(ip);
118 nblocks = dir_blocks(ip);
119 pblocks = VXFS_BLOCK_PER_PAGE(ip->i_sb);
121 for (page = 0; page < npages; page++) {
125 pp = vxfs_get_page(ip->i_mapping, page);
128 kaddr = (caddr_t)page_address(pp);
130 for (block = 0; block <= nblocks && block <= pblocks; block++) {
131 caddr_t baddr, limit;
132 struct vxfs_dirblk *dbp;
133 struct vxfs_direct *de;
135 baddr = kaddr + (block * bsize);
136 limit = baddr + bsize - VXFS_DIRLEN(1);
138 dbp = (struct vxfs_dirblk *)baddr;
139 de = (struct vxfs_direct *)
140 (baddr + VXFS_DIRBLKOV(sbi, dbp));
142 for (; (caddr_t)de <= limit;
143 de = vxfs_next_entry(sbi, de)) {
148 if (vxfs_match(sbi, namelen, name, de)) {
161 * vxfs_inode_by_name - find inode number for dentry
162 * @dip: directory to search in
163 * @dp: dentry we search for
166 * vxfs_inode_by_name finds out the inode number of
167 * the path component described by @dp in @dip.
170 * The wanted inode number on success, else Zero.
173 vxfs_inode_by_name(struct inode *dip, struct dentry *dp)
175 struct vxfs_direct *de;
179 de = vxfs_find_entry(dip, dp, &pp);
181 ino = fs32_to_cpu(VXFS_SBI(dip->i_sb), de->d_ino);
190 * vxfs_lookup - lookup pathname component
191 * @dip: dir in which we lookup
192 * @dp: dentry we lookup
193 * @flags: lookup flags
196 * vxfs_lookup tries to lookup the pathname component described
200 * A NULL-pointer on success, else a negative error code encoded
201 * in the return pointer.
203 static struct dentry *
204 vxfs_lookup(struct inode *dip, struct dentry *dp, unsigned int flags)
206 struct inode *ip = NULL;
209 if (dp->d_name.len > VXFS_NAMELEN)
210 return ERR_PTR(-ENAMETOOLONG);
212 ino = vxfs_inode_by_name(dip, dp);
214 ip = vxfs_iget(dip->i_sb, ino);
223 * vxfs_readdir - read a directory
224 * @fp: the directory to read
225 * @retp: return buffer
226 * @filler: filldir callback
229 * vxfs_readdir fills @retp with directory entries from @fp
230 * using the VFS supplied callback @filler.
236 vxfs_readdir(struct file *fp, struct dir_context *ctx)
238 struct inode *ip = file_inode(fp);
239 struct super_block *sbp = ip->i_sb;
240 struct vxfs_sb_info *sbi = VXFS_SBI(sbp);
241 u_long bsize = sbp->s_blocksize;
242 u_long page, npages, block, pblocks, nblocks, offset;
247 if (!dir_emit_dot(fp, ctx))
252 if (!dir_emit(ctx, "..", 2, VXFS_INO(ip)->vii_dotdot, DT_DIR))
258 if (pos > VXFS_DIRROUND(ip->i_size))
261 npages = dir_pages(ip);
262 nblocks = dir_blocks(ip);
263 pblocks = VXFS_BLOCK_PER_PAGE(sbp);
265 page = pos >> PAGE_SHIFT;
266 offset = pos & ~PAGE_MASK;
267 block = (u_long)(pos >> sbp->s_blocksize_bits) % pblocks;
269 for (; page < npages; page++, block = 0) {
273 pp = vxfs_get_page(ip->i_mapping, page);
276 kaddr = (char *)page_address(pp);
278 for (; block <= nblocks && block <= pblocks; block++) {
280 struct vxfs_dirblk *dbp;
281 struct vxfs_direct *de;
283 baddr = kaddr + (block * bsize);
284 limit = baddr + bsize - VXFS_DIRLEN(1);
286 dbp = (struct vxfs_dirblk *)baddr;
287 de = (struct vxfs_direct *)
290 (baddr + VXFS_DIRBLKOV(sbi, dbp)));
292 for (; (char *)de <= limit;
293 de = vxfs_next_entry(sbi, de)) {
299 offset = (char *)de - kaddr;
300 ctx->pos = ((page << PAGE_SHIFT) | offset) + 2;
301 if (!dir_emit(ctx, de->d_name,
302 fs16_to_cpu(sbi, de->d_namelen),
303 fs32_to_cpu(sbi, de->d_ino),
314 ctx->pos = ((page << PAGE_SHIFT) | offset) + 2;