9c92ab6191415 (Thomas Gleixner 2019-05-29 07:17:56 -0700 1) // SPDX-License-Identifier: GPL-2.0-only
21b6633d516c4 (Steven J. Magnani 2012-10-04 17:14:44 -0700 2) /* fs/fat/nfs.c
21b6633d516c4 (Steven J. Magnani 2012-10-04 17:14:44 -0700 3) */
21b6633d516c4 (Steven J. Magnani 2012-10-04 17:14:44 -0700 4)
21b6633d516c4 (Steven J. Magnani 2012-10-04 17:14:44 -0700 5) #include <linux/exportfs.h>
21b6633d516c4 (Steven J. Magnani 2012-10-04 17:14:44 -0700 6) #include "fat.h"
21b6633d516c4 (Steven J. Magnani 2012-10-04 17:14:44 -0700 7)
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 8) struct fat_fid {
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 9) u32 i_gen;
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 10) u32 i_pos_low;
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 11) u16 i_pos_hi;
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 12) u16 parent_i_pos_hi;
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 13) u32 parent_i_pos_low;
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 14) u32 parent_i_gen;
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 15) };
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 16)
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 17) #define FAT_FID_SIZE_WITHOUT_PARENT 3
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 18) #define FAT_FID_SIZE_WITH_PARENT (sizeof(struct fat_fid)/sizeof(u32))
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 19)
7669e8fb09da4 (Steven J. Magnani 2012-10-04 17:14:45 -0700 20) /**
7669e8fb09da4 (Steven J. Magnani 2012-10-04 17:14:45 -0700 21) * Look up a directory inode given its starting cluster.
21b6633d516c4 (Steven J. Magnani 2012-10-04 17:14:44 -0700 22) */
7669e8fb09da4 (Steven J. Magnani 2012-10-04 17:14:45 -0700 23) static struct inode *fat_dget(struct super_block *sb, int i_logstart)
21b6633d516c4 (Steven J. Magnani 2012-10-04 17:14:44 -0700 24) {
7669e8fb09da4 (Steven J. Magnani 2012-10-04 17:14:45 -0700 25) struct msdos_sb_info *sbi = MSDOS_SB(sb);
7669e8fb09da4 (Steven J. Magnani 2012-10-04 17:14:45 -0700 26) struct hlist_head *head;
7669e8fb09da4 (Steven J. Magnani 2012-10-04 17:14:45 -0700 27) struct msdos_inode_info *i;
7669e8fb09da4 (Steven J. Magnani 2012-10-04 17:14:45 -0700 28) struct inode *inode = NULL;
21b6633d516c4 (Steven J. Magnani 2012-10-04 17:14:44 -0700 29)
7669e8fb09da4 (Steven J. Magnani 2012-10-04 17:14:45 -0700 30) head = sbi->dir_hashtable + fat_dir_hash(i_logstart);
7669e8fb09da4 (Steven J. Magnani 2012-10-04 17:14:45 -0700 31) spin_lock(&sbi->dir_hash_lock);
b67bfe0d42cac (Sasha Levin 2013-02-27 17:06:00 -0800 32) hlist_for_each_entry(i, head, i_dir_hash) {
7669e8fb09da4 (Steven J. Magnani 2012-10-04 17:14:45 -0700 33) BUG_ON(i->vfs_inode.i_sb != sb);
7669e8fb09da4 (Steven J. Magnani 2012-10-04 17:14:45 -0700 34) if (i->i_logstart != i_logstart)
7669e8fb09da4 (Steven J. Magnani 2012-10-04 17:14:45 -0700 35) continue;
7669e8fb09da4 (Steven J. Magnani 2012-10-04 17:14:45 -0700 36) inode = igrab(&i->vfs_inode);
7669e8fb09da4 (Steven J. Magnani 2012-10-04 17:14:45 -0700 37) if (inode)
7669e8fb09da4 (Steven J. Magnani 2012-10-04 17:14:45 -0700 38) break;
21b6633d516c4 (Steven J. Magnani 2012-10-04 17:14:44 -0700 39) }
7669e8fb09da4 (Steven J. Magnani 2012-10-04 17:14:45 -0700 40) spin_unlock(&sbi->dir_hash_lock);
7669e8fb09da4 (Steven J. Magnani 2012-10-04 17:14:45 -0700 41) return inode;
21b6633d516c4 (Steven J. Magnani 2012-10-04 17:14:44 -0700 42) }
21b6633d516c4 (Steven J. Magnani 2012-10-04 17:14:44 -0700 43)
8fceb4e0171f6 (Namjae Jeon 2013-04-29 16:21:12 -0700 44) static struct inode *fat_ilookup(struct super_block *sb, u64 ino, loff_t i_pos)
8fceb4e0171f6 (Namjae Jeon 2013-04-29 16:21:12 -0700 45) {
8fceb4e0171f6 (Namjae Jeon 2013-04-29 16:21:12 -0700 46) if (MSDOS_SB(sb)->options.nfs == FAT_NFS_NOSTALE_RO)
8fceb4e0171f6 (Namjae Jeon 2013-04-29 16:21:12 -0700 47) return fat_iget(sb, i_pos);
8fceb4e0171f6 (Namjae Jeon 2013-04-29 16:21:12 -0700 48)
8fceb4e0171f6 (Namjae Jeon 2013-04-29 16:21:12 -0700 49) else {
8fceb4e0171f6 (Namjae Jeon 2013-04-29 16:21:12 -0700 50) if ((ino < MSDOS_ROOT_INO) || (ino == MSDOS_FSINFO_INO))
8fceb4e0171f6 (Namjae Jeon 2013-04-29 16:21:12 -0700 51) return NULL;
8fceb4e0171f6 (Namjae Jeon 2013-04-29 16:21:12 -0700 52) return ilookup(sb, ino);
8fceb4e0171f6 (Namjae Jeon 2013-04-29 16:21:12 -0700 53) }
8fceb4e0171f6 (Namjae Jeon 2013-04-29 16:21:12 -0700 54) }
8fceb4e0171f6 (Namjae Jeon 2013-04-29 16:21:12 -0700 55)
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 56) static struct inode *__fat_nfs_get_inode(struct super_block *sb,
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 57) u64 ino, u32 generation, loff_t i_pos)
21b6633d516c4 (Steven J. Magnani 2012-10-04 17:14:44 -0700 58) {
8fceb4e0171f6 (Namjae Jeon 2013-04-29 16:21:12 -0700 59) struct inode *inode = fat_ilookup(sb, ino, i_pos);
7669e8fb09da4 (Steven J. Magnani 2012-10-04 17:14:45 -0700 60)
7669e8fb09da4 (Steven J. Magnani 2012-10-04 17:14:45 -0700 61) if (inode && generation && (inode->i_generation != generation)) {
7669e8fb09da4 (Steven J. Magnani 2012-10-04 17:14:45 -0700 62) iput(inode);
7669e8fb09da4 (Steven J. Magnani 2012-10-04 17:14:45 -0700 63) inode = NULL;
7669e8fb09da4 (Steven J. Magnani 2012-10-04 17:14:45 -0700 64) }
8fceb4e0171f6 (Namjae Jeon 2013-04-29 16:21:12 -0700 65) if (inode == NULL && MSDOS_SB(sb)->options.nfs == FAT_NFS_NOSTALE_RO) {
8fceb4e0171f6 (Namjae Jeon 2013-04-29 16:21:12 -0700 66) struct buffer_head *bh = NULL;
8fceb4e0171f6 (Namjae Jeon 2013-04-29 16:21:12 -0700 67) struct msdos_dir_entry *de ;
8fceb4e0171f6 (Namjae Jeon 2013-04-29 16:21:12 -0700 68) sector_t blocknr;
8fceb4e0171f6 (Namjae Jeon 2013-04-29 16:21:12 -0700 69) int offset;
8fceb4e0171f6 (Namjae Jeon 2013-04-29 16:21:12 -0700 70) fat_get_blknr_offset(MSDOS_SB(sb), i_pos, &blocknr, &offset);
8fceb4e0171f6 (Namjae Jeon 2013-04-29 16:21:12 -0700 71) bh = sb_bread(sb, blocknr);
8fceb4e0171f6 (Namjae Jeon 2013-04-29 16:21:12 -0700 72) if (!bh) {
8fceb4e0171f6 (Namjae Jeon 2013-04-29 16:21:12 -0700 73) fat_msg(sb, KERN_ERR,
8fceb4e0171f6 (Namjae Jeon 2013-04-29 16:21:12 -0700 74) "unable to read block(%llu) for building NFS inode",
8fceb4e0171f6 (Namjae Jeon 2013-04-29 16:21:12 -0700 75) (llu)blocknr);
8fceb4e0171f6 (Namjae Jeon 2013-04-29 16:21:12 -0700 76) return inode;
8fceb4e0171f6 (Namjae Jeon 2013-04-29 16:21:12 -0700 77) }
8fceb4e0171f6 (Namjae Jeon 2013-04-29 16:21:12 -0700 78) de = (struct msdos_dir_entry *)bh->b_data;
8fceb4e0171f6 (Namjae Jeon 2013-04-29 16:21:12 -0700 79) /* If a file is deleted on server and client is not updated
8fceb4e0171f6 (Namjae Jeon 2013-04-29 16:21:12 -0700 80) * yet, we must not build the inode upon a lookup call.
8fceb4e0171f6 (Namjae Jeon 2013-04-29 16:21:12 -0700 81) */
8fceb4e0171f6 (Namjae Jeon 2013-04-29 16:21:12 -0700 82) if (IS_FREE(de[offset].name))
8fceb4e0171f6 (Namjae Jeon 2013-04-29 16:21:12 -0700 83) inode = NULL;
8fceb4e0171f6 (Namjae Jeon 2013-04-29 16:21:12 -0700 84) else
8fceb4e0171f6 (Namjae Jeon 2013-04-29 16:21:12 -0700 85) inode = fat_build_inode(sb, &de[offset], i_pos);
8fceb4e0171f6 (Namjae Jeon 2013-04-29 16:21:12 -0700 86) brelse(bh);
8fceb4e0171f6 (Namjae Jeon 2013-04-29 16:21:12 -0700 87) }
7669e8fb09da4 (Steven J. Magnani 2012-10-04 17:14:45 -0700 88)
7669e8fb09da4 (Steven J. Magnani 2012-10-04 17:14:45 -0700 89) return inode;
21b6633d516c4 (Steven J. Magnani 2012-10-04 17:14:44 -0700 90) }
21b6633d516c4 (Steven J. Magnani 2012-10-04 17:14:44 -0700 91)
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 92) static struct inode *fat_nfs_get_inode(struct super_block *sb,
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 93) u64 ino, u32 generation)
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 94) {
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 95)
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 96) return __fat_nfs_get_inode(sb, ino, generation, 0);
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 97) }
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 98)
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 99) static int
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 100) fat_encode_fh_nostale(struct inode *inode, __u32 *fh, int *lenp,
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 101) struct inode *parent)
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 102) {
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 103) int len = *lenp;
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 104) struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 105) struct fat_fid *fid = (struct fat_fid *) fh;
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 106) loff_t i_pos;
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 107) int type = FILEID_FAT_WITHOUT_PARENT;
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 108)
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 109) if (parent) {
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 110) if (len < FAT_FID_SIZE_WITH_PARENT) {
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 111) *lenp = FAT_FID_SIZE_WITH_PARENT;
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 112) return FILEID_INVALID;
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 113) }
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 114) } else {
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 115) if (len < FAT_FID_SIZE_WITHOUT_PARENT) {
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 116) *lenp = FAT_FID_SIZE_WITHOUT_PARENT;
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 117) return FILEID_INVALID;
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 118) }
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 119) }
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 120)
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 121) i_pos = fat_i_pos_read(sbi, inode);
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 122) *lenp = FAT_FID_SIZE_WITHOUT_PARENT;
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 123) fid->i_gen = inode->i_generation;
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 124) fid->i_pos_low = i_pos & 0xFFFFFFFF;
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 125) fid->i_pos_hi = (i_pos >> 32) & 0xFFFF;
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 126) if (parent) {
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 127) i_pos = fat_i_pos_read(sbi, parent);
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 128) fid->parent_i_pos_hi = (i_pos >> 32) & 0xFFFF;
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 129) fid->parent_i_pos_low = i_pos & 0xFFFFFFFF;
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 130) fid->parent_i_gen = parent->i_generation;
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 131) type = FILEID_FAT_WITH_PARENT;
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 132) *lenp = FAT_FID_SIZE_WITH_PARENT;
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 133) }
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 134)
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 135) return type;
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 136) }
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 137)
21b6633d516c4 (Steven J. Magnani 2012-10-04 17:14:44 -0700 138) /**
21b6633d516c4 (Steven J. Magnani 2012-10-04 17:14:44 -0700 139) * Map a NFS file handle to a corresponding dentry.
21b6633d516c4 (Steven J. Magnani 2012-10-04 17:14:44 -0700 140) * The dentry may or may not be connected to the filesystem root.
21b6633d516c4 (Steven J. Magnani 2012-10-04 17:14:44 -0700 141) */
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 142) static struct dentry *fat_fh_to_dentry(struct super_block *sb, struct fid *fid,
21b6633d516c4 (Steven J. Magnani 2012-10-04 17:14:44 -0700 143) int fh_len, int fh_type)
21b6633d516c4 (Steven J. Magnani 2012-10-04 17:14:44 -0700 144) {
7669e8fb09da4 (Steven J. Magnani 2012-10-04 17:14:45 -0700 145) return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
7669e8fb09da4 (Steven J. Magnani 2012-10-04 17:14:45 -0700 146) fat_nfs_get_inode);
7669e8fb09da4 (Steven J. Magnani 2012-10-04 17:14:45 -0700 147) }
21b6633d516c4 (Steven J. Magnani 2012-10-04 17:14:44 -0700 148)
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 149) static struct dentry *fat_fh_to_dentry_nostale(struct super_block *sb,
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 150) struct fid *fh, int fh_len,
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 151) int fh_type)
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 152) {
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 153) struct inode *inode = NULL;
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 154) struct fat_fid *fid = (struct fat_fid *)fh;
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 155) loff_t i_pos;
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 156)
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 157) switch (fh_type) {
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 158) case FILEID_FAT_WITHOUT_PARENT:
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 159) if (fh_len < FAT_FID_SIZE_WITHOUT_PARENT)
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 160) return NULL;
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 161) break;
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 162) case FILEID_FAT_WITH_PARENT:
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 163) if (fh_len < FAT_FID_SIZE_WITH_PARENT)
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 164) return NULL;
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 165) break;
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 166) default:
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 167) return NULL;
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 168) }
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 169) i_pos = fid->i_pos_hi;
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 170) i_pos = (i_pos << 32) | (fid->i_pos_low);
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 171) inode = __fat_nfs_get_inode(sb, 0, fid->i_gen, i_pos);
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 172)
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 173) return d_obtain_alias(inode);
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 174) }
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 175)
7669e8fb09da4 (Steven J. Magnani 2012-10-04 17:14:45 -0700 176) /*
7669e8fb09da4 (Steven J. Magnani 2012-10-04 17:14:45 -0700 177) * Find the parent for a file specified by NFS handle.
7669e8fb09da4 (Steven J. Magnani 2012-10-04 17:14:45 -0700 178) * This requires that the handle contain the i_ino of the parent.
7669e8fb09da4 (Steven J. Magnani 2012-10-04 17:14:45 -0700 179) */
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 180) static struct dentry *fat_fh_to_parent(struct super_block *sb, struct fid *fid,
7669e8fb09da4 (Steven J. Magnani 2012-10-04 17:14:45 -0700 181) int fh_len, int fh_type)
7669e8fb09da4 (Steven J. Magnani 2012-10-04 17:14:45 -0700 182) {
7669e8fb09da4 (Steven J. Magnani 2012-10-04 17:14:45 -0700 183) return generic_fh_to_parent(sb, fid, fh_len, fh_type,
7669e8fb09da4 (Steven J. Magnani 2012-10-04 17:14:45 -0700 184) fat_nfs_get_inode);
21b6633d516c4 (Steven J. Magnani 2012-10-04 17:14:44 -0700 185) }
21b6633d516c4 (Steven J. Magnani 2012-10-04 17:14:44 -0700 186)
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 187) static struct dentry *fat_fh_to_parent_nostale(struct super_block *sb,
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 188) struct fid *fh, int fh_len,
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 189) int fh_type)
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 190) {
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 191) struct inode *inode = NULL;
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 192) struct fat_fid *fid = (struct fat_fid *)fh;
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 193) loff_t i_pos;
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 194)
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 195) if (fh_len < FAT_FID_SIZE_WITH_PARENT)
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 196) return NULL;
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 197)
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 198) switch (fh_type) {
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 199) case FILEID_FAT_WITH_PARENT:
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 200) i_pos = fid->parent_i_pos_hi;
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 201) i_pos = (i_pos << 32) | (fid->parent_i_pos_low);
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 202) inode = __fat_nfs_get_inode(sb, 0, fid->parent_i_gen, i_pos);
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 203) break;
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 204) }
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 205)
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 206) return d_obtain_alias(inode);
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 207) }
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 208)
f1e6fb0ab451d (Namjae Jeon 2013-04-29 16:21:14 -0700 209) /*
f1e6fb0ab451d (Namjae Jeon 2013-04-29 16:21:14 -0700 210) * Rebuild the parent for a directory that is not connected
f1e6fb0ab451d (Namjae Jeon 2013-04-29 16:21:14 -0700 211) * to the filesystem root
f1e6fb0ab451d (Namjae Jeon 2013-04-29 16:21:14 -0700 212) */
f1e6fb0ab451d (Namjae Jeon 2013-04-29 16:21:14 -0700 213) static
f1e6fb0ab451d (Namjae Jeon 2013-04-29 16:21:14 -0700 214) struct inode *fat_rebuild_parent(struct super_block *sb, int parent_logstart)
f1e6fb0ab451d (Namjae Jeon 2013-04-29 16:21:14 -0700 215) {
f1e6fb0ab451d (Namjae Jeon 2013-04-29 16:21:14 -0700 216) int search_clus, clus_to_match;
f1e6fb0ab451d (Namjae Jeon 2013-04-29 16:21:14 -0700 217) struct msdos_dir_entry *de;
f1e6fb0ab451d (Namjae Jeon 2013-04-29 16:21:14 -0700 218) struct inode *parent = NULL;
f1e6fb0ab451d (Namjae Jeon 2013-04-29 16:21:14 -0700 219) struct inode *dummy_grand_parent = NULL;
f1e6fb0ab451d (Namjae Jeon 2013-04-29 16:21:14 -0700 220) struct fat_slot_info sinfo;
f1e6fb0ab451d (Namjae Jeon 2013-04-29 16:21:14 -0700 221) struct msdos_sb_info *sbi = MSDOS_SB(sb);
f1e6fb0ab451d (Namjae Jeon 2013-04-29 16:21:14 -0700 222) sector_t blknr = fat_clus_to_blknr(sbi, parent_logstart);
f1e6fb0ab451d (Namjae Jeon 2013-04-29 16:21:14 -0700 223) struct buffer_head *parent_bh = sb_bread(sb, blknr);
f1e6fb0ab451d (Namjae Jeon 2013-04-29 16:21:14 -0700 224) if (!parent_bh) {
f1e6fb0ab451d (Namjae Jeon 2013-04-29 16:21:14 -0700 225) fat_msg(sb, KERN_ERR,
f1e6fb0ab451d (Namjae Jeon 2013-04-29 16:21:14 -0700 226) "unable to read cluster of parent directory");
f1e6fb0ab451d (Namjae Jeon 2013-04-29 16:21:14 -0700 227) return NULL;
f1e6fb0ab451d (Namjae Jeon 2013-04-29 16:21:14 -0700 228) }
f1e6fb0ab451d (Namjae Jeon 2013-04-29 16:21:14 -0700 229)
f1e6fb0ab451d (Namjae Jeon 2013-04-29 16:21:14 -0700 230) de = (struct msdos_dir_entry *) parent_bh->b_data;
f1e6fb0ab451d (Namjae Jeon 2013-04-29 16:21:14 -0700 231) clus_to_match = fat_get_start(sbi, &de[0]);
f1e6fb0ab451d (Namjae Jeon 2013-04-29 16:21:14 -0700 232) search_clus = fat_get_start(sbi, &de[1]);
f1e6fb0ab451d (Namjae Jeon 2013-04-29 16:21:14 -0700 233)
f1e6fb0ab451d (Namjae Jeon 2013-04-29 16:21:14 -0700 234) dummy_grand_parent = fat_dget(sb, search_clus);
f1e6fb0ab451d (Namjae Jeon 2013-04-29 16:21:14 -0700 235) if (!dummy_grand_parent) {
f1e6fb0ab451d (Namjae Jeon 2013-04-29 16:21:14 -0700 236) dummy_grand_parent = new_inode(sb);
f1e6fb0ab451d (Namjae Jeon 2013-04-29 16:21:14 -0700 237) if (!dummy_grand_parent) {
f1e6fb0ab451d (Namjae Jeon 2013-04-29 16:21:14 -0700 238) brelse(parent_bh);
f1e6fb0ab451d (Namjae Jeon 2013-04-29 16:21:14 -0700 239) return parent;
f1e6fb0ab451d (Namjae Jeon 2013-04-29 16:21:14 -0700 240) }
f1e6fb0ab451d (Namjae Jeon 2013-04-29 16:21:14 -0700 241)
f1e6fb0ab451d (Namjae Jeon 2013-04-29 16:21:14 -0700 242) dummy_grand_parent->i_ino = iunique(sb, MSDOS_ROOT_INO);
f1e6fb0ab451d (Namjae Jeon 2013-04-29 16:21:14 -0700 243) fat_fill_inode(dummy_grand_parent, &de[1]);
f1e6fb0ab451d (Namjae Jeon 2013-04-29 16:21:14 -0700 244) MSDOS_I(dummy_grand_parent)->i_pos = -1;
f1e6fb0ab451d (Namjae Jeon 2013-04-29 16:21:14 -0700 245) }
f1e6fb0ab451d (Namjae Jeon 2013-04-29 16:21:14 -0700 246)
f1e6fb0ab451d (Namjae Jeon 2013-04-29 16:21:14 -0700 247) if (!fat_scan_logstart(dummy_grand_parent, clus_to_match, &sinfo))
f1e6fb0ab451d (Namjae Jeon 2013-04-29 16:21:14 -0700 248) parent = fat_build_inode(sb, sinfo.de, sinfo.i_pos);
f1e6fb0ab451d (Namjae Jeon 2013-04-29 16:21:14 -0700 249)
f1e6fb0ab451d (Namjae Jeon 2013-04-29 16:21:14 -0700 250) brelse(parent_bh);
f1e6fb0ab451d (Namjae Jeon 2013-04-29 16:21:14 -0700 251) iput(dummy_grand_parent);
f1e6fb0ab451d (Namjae Jeon 2013-04-29 16:21:14 -0700 252)
f1e6fb0ab451d (Namjae Jeon 2013-04-29 16:21:14 -0700 253) return parent;
f1e6fb0ab451d (Namjae Jeon 2013-04-29 16:21:14 -0700 254) }
f1e6fb0ab451d (Namjae Jeon 2013-04-29 16:21:14 -0700 255)
21b6633d516c4 (Steven J. Magnani 2012-10-04 17:14:44 -0700 256) /*
21b6633d516c4 (Steven J. Magnani 2012-10-04 17:14:44 -0700 257) * Find the parent for a directory that is not currently connected to
21b6633d516c4 (Steven J. Magnani 2012-10-04 17:14:44 -0700 258) * the filesystem root.
21b6633d516c4 (Steven J. Magnani 2012-10-04 17:14:44 -0700 259) *
2b0143b5c986b (David Howells 2015-03-17 22:25:59 +0000 260) * On entry, the caller holds d_inode(child_dir)->i_mutex.
21b6633d516c4 (Steven J. Magnani 2012-10-04 17:14:44 -0700 261) */
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 262) static struct dentry *fat_get_parent(struct dentry *child_dir)
21b6633d516c4 (Steven J. Magnani 2012-10-04 17:14:44 -0700 263) {
21b6633d516c4 (Steven J. Magnani 2012-10-04 17:14:44 -0700 264) struct super_block *sb = child_dir->d_sb;
21b6633d516c4 (Steven J. Magnani 2012-10-04 17:14:44 -0700 265) struct buffer_head *bh = NULL;
21b6633d516c4 (Steven J. Magnani 2012-10-04 17:14:44 -0700 266) struct msdos_dir_entry *de;
7669e8fb09da4 (Steven J. Magnani 2012-10-04 17:14:45 -0700 267) struct inode *parent_inode = NULL;
f1e6fb0ab451d (Namjae Jeon 2013-04-29 16:21:14 -0700 268) struct msdos_sb_info *sbi = MSDOS_SB(sb);
21b6633d516c4 (Steven J. Magnani 2012-10-04 17:14:44 -0700 269)
2b0143b5c986b (David Howells 2015-03-17 22:25:59 +0000 270) if (!fat_get_dotdot_entry(d_inode(child_dir), &bh, &de)) {
f1e6fb0ab451d (Namjae Jeon 2013-04-29 16:21:14 -0700 271) int parent_logstart = fat_get_start(sbi, de);
7669e8fb09da4 (Steven J. Magnani 2012-10-04 17:14:45 -0700 272) parent_inode = fat_dget(sb, parent_logstart);
f1e6fb0ab451d (Namjae Jeon 2013-04-29 16:21:14 -0700 273) if (!parent_inode && sbi->options.nfs == FAT_NFS_NOSTALE_RO)
f1e6fb0ab451d (Namjae Jeon 2013-04-29 16:21:14 -0700 274) parent_inode = fat_rebuild_parent(sb, parent_logstart);
21b6633d516c4 (Steven J. Magnani 2012-10-04 17:14:44 -0700 275) }
21b6633d516c4 (Steven J. Magnani 2012-10-04 17:14:44 -0700 276) brelse(bh);
21b6633d516c4 (Steven J. Magnani 2012-10-04 17:14:44 -0700 277)
7669e8fb09da4 (Steven J. Magnani 2012-10-04 17:14:45 -0700 278) return d_obtain_alias(parent_inode);
21b6633d516c4 (Steven J. Magnani 2012-10-04 17:14:44 -0700 279) }
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 280)
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 281) const struct export_operations fat_export_ops = {
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 282) .fh_to_dentry = fat_fh_to_dentry,
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 283) .fh_to_parent = fat_fh_to_parent,
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 284) .get_parent = fat_get_parent,
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 285) };
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 286)
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 287) const struct export_operations fat_export_ops_nostale = {
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 288) .encode_fh = fat_encode_fh_nostale,
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 289) .fh_to_dentry = fat_fh_to_dentry_nostale,
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 290) .fh_to_parent = fat_fh_to_parent_nostale,
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 291) .get_parent = fat_get_parent,
ea3983ace6b79 (Namjae Jeon 2013-04-29 16:21:11 -0700 292) };
VisionFive2 Linux kernel
StarFive Tech Linux Kernel for VisionFive (JH7110) boards (mirror)
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