Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   1) // SPDX-License-Identifier: GPL-2.0-only
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   2) /* fs/fat/nfs.c
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   3)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   4) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   5) #include <linux/exportfs.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   6) #include "fat.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   7) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   8) struct fat_fid {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   9) 	u32 i_gen;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  10) 	u32 i_pos_low;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  11) 	u16 i_pos_hi;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  12) 	u16 parent_i_pos_hi;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  13) 	u32 parent_i_pos_low;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  14) 	u32 parent_i_gen;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  15) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  16) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  17) #define FAT_FID_SIZE_WITHOUT_PARENT 3
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  18) #define FAT_FID_SIZE_WITH_PARENT (sizeof(struct fat_fid)/sizeof(u32))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  19) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  20) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  21)  * Look up a directory inode given its starting cluster.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  22)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  23) static struct inode *fat_dget(struct super_block *sb, int i_logstart)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  24) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  25) 	struct msdos_sb_info *sbi = MSDOS_SB(sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  26) 	struct hlist_head *head;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  27) 	struct msdos_inode_info *i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  28) 	struct inode *inode = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  29) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  30) 	head = sbi->dir_hashtable + fat_dir_hash(i_logstart);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  31) 	spin_lock(&sbi->dir_hash_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  32) 	hlist_for_each_entry(i, head, i_dir_hash) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  33) 		BUG_ON(i->vfs_inode.i_sb != sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  34) 		if (i->i_logstart != i_logstart)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  35) 			continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  36) 		inode = igrab(&i->vfs_inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  37) 		if (inode)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  38) 			break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  39) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  40) 	spin_unlock(&sbi->dir_hash_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  41) 	return inode;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  42) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  43) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  44) static struct inode *fat_ilookup(struct super_block *sb, u64 ino, loff_t i_pos)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  45) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  46) 	if (MSDOS_SB(sb)->options.nfs == FAT_NFS_NOSTALE_RO)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  47) 		return fat_iget(sb, i_pos);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  48) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  49) 	else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  50) 		if ((ino < MSDOS_ROOT_INO) || (ino == MSDOS_FSINFO_INO))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  51) 			return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  52) 		return ilookup(sb, ino);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  53) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  54) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  55) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  56) static struct inode *__fat_nfs_get_inode(struct super_block *sb,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  57) 				       u64 ino, u32 generation, loff_t i_pos)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  58) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  59) 	struct inode *inode = fat_ilookup(sb, ino, i_pos);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  60) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  61) 	if (inode && generation && (inode->i_generation != generation)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  62) 		iput(inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  63) 		inode = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  64) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  65) 	if (inode == NULL && MSDOS_SB(sb)->options.nfs == FAT_NFS_NOSTALE_RO) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  66) 		struct buffer_head *bh = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  67) 		struct msdos_dir_entry *de ;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  68) 		sector_t blocknr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  69) 		int offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  70) 		fat_get_blknr_offset(MSDOS_SB(sb), i_pos, &blocknr, &offset);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  71) 		bh = sb_bread(sb, blocknr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  72) 		if (!bh) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  73) 			fat_msg(sb, KERN_ERR,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  74) 				"unable to read block(%llu) for building NFS inode",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  75) 				(llu)blocknr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  76) 			return inode;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  77) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  78) 		de = (struct msdos_dir_entry *)bh->b_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  79) 		/* If a file is deleted on server and client is not updated
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  80) 		 * yet, we must not build the inode upon a lookup call.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  81) 		 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  82) 		if (IS_FREE(de[offset].name))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  83) 			inode = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  84) 		else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  85) 			inode = fat_build_inode(sb, &de[offset], i_pos);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  86) 		brelse(bh);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  87) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  88) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  89) 	return inode;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  90) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  91) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  92) static struct inode *fat_nfs_get_inode(struct super_block *sb,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  93) 				       u64 ino, u32 generation)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  94) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  95) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  96) 	return __fat_nfs_get_inode(sb, ino, generation, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  97) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  98) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  99) static int
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) fat_encode_fh_nostale(struct inode *inode, __u32 *fh, int *lenp,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) 		      struct inode *parent)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) 	int len = *lenp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) 	struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) 	struct fat_fid *fid = (struct fat_fid *) fh;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) 	loff_t i_pos;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) 	int type = FILEID_FAT_WITHOUT_PARENT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) 	if (parent) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) 		if (len < FAT_FID_SIZE_WITH_PARENT) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) 			*lenp = FAT_FID_SIZE_WITH_PARENT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) 			return FILEID_INVALID;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) 	} else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) 		if (len < FAT_FID_SIZE_WITHOUT_PARENT) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) 			*lenp = FAT_FID_SIZE_WITHOUT_PARENT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) 			return FILEID_INVALID;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) 	i_pos = fat_i_pos_read(sbi, inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) 	*lenp = FAT_FID_SIZE_WITHOUT_PARENT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) 	fid->i_gen = inode->i_generation;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) 	fid->i_pos_low = i_pos & 0xFFFFFFFF;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) 	fid->i_pos_hi = (i_pos >> 32) & 0xFFFF;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) 	if (parent) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) 		i_pos = fat_i_pos_read(sbi, parent);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) 		fid->parent_i_pos_hi = (i_pos >> 32) & 0xFFFF;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) 		fid->parent_i_pos_low = i_pos & 0xFFFFFFFF;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) 		fid->parent_i_gen = parent->i_generation;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) 		type = FILEID_FAT_WITH_PARENT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) 		*lenp = FAT_FID_SIZE_WITH_PARENT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) 	return type;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139)  * Map a NFS file handle to a corresponding dentry.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140)  * The dentry may or may not be connected to the filesystem root.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) static struct dentry *fat_fh_to_dentry(struct super_block *sb, struct fid *fid,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) 				int fh_len, int fh_type)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) 	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) 				    fat_nfs_get_inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) static struct dentry *fat_fh_to_dentry_nostale(struct super_block *sb,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) 					       struct fid *fh, int fh_len,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) 					       int fh_type)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) 	struct inode *inode = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) 	struct fat_fid *fid = (struct fat_fid *)fh;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) 	loff_t i_pos;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) 	switch (fh_type) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) 	case FILEID_FAT_WITHOUT_PARENT:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) 		if (fh_len < FAT_FID_SIZE_WITHOUT_PARENT)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) 			return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) 		break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) 	case FILEID_FAT_WITH_PARENT:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) 		if (fh_len < FAT_FID_SIZE_WITH_PARENT)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) 			return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) 		break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) 	default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) 		return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) 	i_pos = fid->i_pos_hi;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) 	i_pos = (i_pos << 32) | (fid->i_pos_low);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) 	inode = __fat_nfs_get_inode(sb, 0, fid->i_gen, i_pos);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) 	return d_obtain_alias(inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177)  * Find the parent for a file specified by NFS handle.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178)  * This requires that the handle contain the i_ino of the parent.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) static struct dentry *fat_fh_to_parent(struct super_block *sb, struct fid *fid,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) 				int fh_len, int fh_type)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) 	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) 				    fat_nfs_get_inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) static struct dentry *fat_fh_to_parent_nostale(struct super_block *sb,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) 					       struct fid *fh, int fh_len,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) 					       int fh_type)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) 	struct inode *inode = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) 	struct fat_fid *fid = (struct fat_fid *)fh;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) 	loff_t i_pos;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) 	if (fh_len < FAT_FID_SIZE_WITH_PARENT)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) 		return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) 	switch (fh_type) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) 	case FILEID_FAT_WITH_PARENT:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) 		i_pos = fid->parent_i_pos_hi;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) 		i_pos = (i_pos << 32) | (fid->parent_i_pos_low);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) 		inode = __fat_nfs_get_inode(sb, 0, fid->parent_i_gen, i_pos);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) 		break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) 	return d_obtain_alias(inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210)  * Rebuild the parent for a directory that is not connected
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211)  *  to the filesystem root
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) static
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) struct inode *fat_rebuild_parent(struct super_block *sb, int parent_logstart)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) 	int search_clus, clus_to_match;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) 	struct msdos_dir_entry *de;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) 	struct inode *parent = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) 	struct inode *dummy_grand_parent = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) 	struct fat_slot_info sinfo;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) 	struct msdos_sb_info *sbi = MSDOS_SB(sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) 	sector_t blknr = fat_clus_to_blknr(sbi, parent_logstart);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) 	struct buffer_head *parent_bh = sb_bread(sb, blknr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) 	if (!parent_bh) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) 		fat_msg(sb, KERN_ERR,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) 			"unable to read cluster of parent directory");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) 		return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) 	de = (struct msdos_dir_entry *) parent_bh->b_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) 	clus_to_match = fat_get_start(sbi, &de[0]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) 	search_clus = fat_get_start(sbi, &de[1]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) 	dummy_grand_parent = fat_dget(sb, search_clus);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) 	if (!dummy_grand_parent) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) 		dummy_grand_parent = new_inode(sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) 		if (!dummy_grand_parent) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) 			brelse(parent_bh);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) 			return parent;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) 		dummy_grand_parent->i_ino = iunique(sb, MSDOS_ROOT_INO);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) 		fat_fill_inode(dummy_grand_parent, &de[1]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) 		MSDOS_I(dummy_grand_parent)->i_pos = -1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) 	if (!fat_scan_logstart(dummy_grand_parent, clus_to_match, &sinfo))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) 		parent = fat_build_inode(sb, sinfo.de, sinfo.i_pos);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) 	brelse(parent_bh);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) 	iput(dummy_grand_parent);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) 	return parent;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257)  * Find the parent for a directory that is not currently connected to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258)  * the filesystem root.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260)  * On entry, the caller holds d_inode(child_dir)->i_mutex.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) static struct dentry *fat_get_parent(struct dentry *child_dir)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) 	struct super_block *sb = child_dir->d_sb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265) 	struct buffer_head *bh = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) 	struct msdos_dir_entry *de;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267) 	struct inode *parent_inode = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268) 	struct msdos_sb_info *sbi = MSDOS_SB(sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) 	if (!fat_get_dotdot_entry(d_inode(child_dir), &bh, &de)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271) 		int parent_logstart = fat_get_start(sbi, de);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) 		parent_inode = fat_dget(sb, parent_logstart);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) 		if (!parent_inode && sbi->options.nfs == FAT_NFS_NOSTALE_RO)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) 			parent_inode = fat_rebuild_parent(sb, parent_logstart);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) 	brelse(bh);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) 	return d_obtain_alias(parent_inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) const struct export_operations fat_export_ops = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282) 	.fh_to_dentry   = fat_fh_to_dentry,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) 	.fh_to_parent   = fat_fh_to_parent,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284) 	.get_parent     = fat_get_parent,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287) const struct export_operations fat_export_ops_nostale = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288) 	.encode_fh      = fat_encode_fh_nostale,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289) 	.fh_to_dentry   = fat_fh_to_dentry_nostale,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290) 	.fh_to_parent   = fat_fh_to_parent_nostale,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291) 	.get_parent     = fat_get_parent,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292) };