~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/fs/efs/dir.c

Version: ~ [ linux-5.9-rc6 ] ~ [ linux-5.8.10 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.66 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.146 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.198 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.236 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.236 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.85 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 // SPDX-License-Identifier: GPL-2.0
  2 /*
  3  * dir.c
  4  *
  5  * Copyright (c) 1999 Al Smith
  6  */
  7 
  8 #include <linux/buffer_head.h>
  9 #include "efs.h"
 10 
 11 static int efs_readdir(struct file *, struct dir_context *);
 12 
 13 const struct file_operations efs_dir_operations = {
 14         .llseek         = generic_file_llseek,
 15         .read           = generic_read_dir,
 16         .iterate_shared = efs_readdir,
 17 };
 18 
 19 const struct inode_operations efs_dir_inode_operations = {
 20         .lookup         = efs_lookup,
 21 };
 22 
 23 static int efs_readdir(struct file *file, struct dir_context *ctx)
 24 {
 25         struct inode *inode = file_inode(file);
 26         efs_block_t             block;
 27         int                     slot;
 28 
 29         if (inode->i_size & (EFS_DIRBSIZE-1))
 30                 pr_warn("%s(): directory size not a multiple of EFS_DIRBSIZE\n",
 31                         __func__);
 32 
 33         /* work out where this entry can be found */
 34         block = ctx->pos >> EFS_DIRBSIZE_BITS;
 35 
 36         /* each block contains at most 256 slots */
 37         slot  = ctx->pos & 0xff;
 38 
 39         /* look at all blocks */
 40         while (block < inode->i_blocks) {
 41                 struct efs_dir          *dirblock;
 42                 struct buffer_head *bh;
 43 
 44                 /* read the dir block */
 45                 bh = sb_bread(inode->i_sb, efs_bmap(inode, block));
 46 
 47                 if (!bh) {
 48                         pr_err("%s(): failed to read dir block %d\n",
 49                                __func__, block);
 50                         break;
 51                 }
 52 
 53                 dirblock = (struct efs_dir *) bh->b_data; 
 54 
 55                 if (be16_to_cpu(dirblock->magic) != EFS_DIRBLK_MAGIC) {
 56                         pr_err("%s(): invalid directory block\n", __func__);
 57                         brelse(bh);
 58                         break;
 59                 }
 60 
 61                 for (; slot < dirblock->slots; slot++) {
 62                         struct efs_dentry *dirslot;
 63                         efs_ino_t inodenum;
 64                         const char *nameptr;
 65                         int namelen;
 66 
 67                         if (dirblock->space[slot] == 0)
 68                                 continue;
 69 
 70                         dirslot  = (struct efs_dentry *) (((char *) bh->b_data) + EFS_SLOTAT(dirblock, slot));
 71 
 72                         inodenum = be32_to_cpu(dirslot->inode);
 73                         namelen  = dirslot->namelen;
 74                         nameptr  = dirslot->name;
 75                         pr_debug("%s(): block %d slot %d/%d: inode %u, name \"%s\", namelen %u\n",
 76                                  __func__, block, slot, dirblock->slots-1,
 77                                  inodenum, nameptr, namelen);
 78                         if (!namelen)
 79                                 continue;
 80                         /* found the next entry */
 81                         ctx->pos = (block << EFS_DIRBSIZE_BITS) | slot;
 82 
 83                         /* sanity check */
 84                         if (nameptr - (char *) dirblock + namelen > EFS_DIRBSIZE) {
 85                                 pr_warn("directory entry %d exceeds directory block\n",
 86                                         slot);
 87                                 continue;
 88                         }
 89 
 90                         /* copy filename and data in dirslot */
 91                         if (!dir_emit(ctx, nameptr, namelen, inodenum, DT_UNKNOWN)) {
 92                                 brelse(bh);
 93                                 return 0;
 94                         }
 95                 }
 96                 brelse(bh);
 97 
 98                 slot = 0;
 99                 block++;
100         }
101         ctx->pos = (block << EFS_DIRBSIZE_BITS) | slot;
102         return 0;
103 }
104 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp