Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   1) // SPDX-License-Identifier: GPL-2.0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   2) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   3) #include <linux/fs.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   4) #include <linux/types.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   5) #include "ctree.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   6) #include "disk-io.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   7) #include "btrfs_inode.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   8) #include "print-tree.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   9) #include "export.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  10) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  11) #define BTRFS_FID_SIZE_NON_CONNECTABLE (offsetof(struct btrfs_fid, \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  12) 						 parent_objectid) / 4)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  13) #define BTRFS_FID_SIZE_CONNECTABLE (offsetof(struct btrfs_fid, \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  14) 					     parent_root_objectid) / 4)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  15) #define BTRFS_FID_SIZE_CONNECTABLE_ROOT (sizeof(struct btrfs_fid) / 4)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  16) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  17) static int btrfs_encode_fh(struct inode *inode, u32 *fh, int *max_len,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  18) 			   struct inode *parent)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  19) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  20) 	struct btrfs_fid *fid = (struct btrfs_fid *)fh;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  21) 	int len = *max_len;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  22) 	int type;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  23) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  24) 	if (parent && (len < BTRFS_FID_SIZE_CONNECTABLE)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  25) 		*max_len = BTRFS_FID_SIZE_CONNECTABLE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  26) 		return FILEID_INVALID;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  27) 	} else if (len < BTRFS_FID_SIZE_NON_CONNECTABLE) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  28) 		*max_len = BTRFS_FID_SIZE_NON_CONNECTABLE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  29) 		return FILEID_INVALID;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  30) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  31) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  32) 	len  = BTRFS_FID_SIZE_NON_CONNECTABLE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  33) 	type = FILEID_BTRFS_WITHOUT_PARENT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  34) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  35) 	fid->objectid = btrfs_ino(BTRFS_I(inode));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  36) 	fid->root_objectid = BTRFS_I(inode)->root->root_key.objectid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  37) 	fid->gen = inode->i_generation;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  38) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  39) 	if (parent) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  40) 		u64 parent_root_id;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  41) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  42) 		fid->parent_objectid = BTRFS_I(parent)->location.objectid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  43) 		fid->parent_gen = parent->i_generation;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  44) 		parent_root_id = BTRFS_I(parent)->root->root_key.objectid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  45) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  46) 		if (parent_root_id != fid->root_objectid) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  47) 			fid->parent_root_objectid = parent_root_id;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  48) 			len = BTRFS_FID_SIZE_CONNECTABLE_ROOT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  49) 			type = FILEID_BTRFS_WITH_PARENT_ROOT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  50) 		} else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  51) 			len = BTRFS_FID_SIZE_CONNECTABLE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  52) 			type = FILEID_BTRFS_WITH_PARENT;
^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) 	*max_len = len;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  57) 	return type;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  58) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  59) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  60) struct dentry *btrfs_get_dentry(struct super_block *sb, u64 objectid,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  61) 				u64 root_objectid, u32 generation,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  62) 				int check_generation)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  63) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  64) 	struct btrfs_fs_info *fs_info = btrfs_sb(sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  65) 	struct btrfs_root *root;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  66) 	struct inode *inode;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  67) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  68) 	if (objectid < BTRFS_FIRST_FREE_OBJECTID)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  69) 		return ERR_PTR(-ESTALE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  70) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  71) 	root = btrfs_get_fs_root(fs_info, root_objectid, true);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  72) 	if (IS_ERR(root))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  73) 		return ERR_CAST(root);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  74) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  75) 	inode = btrfs_iget(sb, objectid, root);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  76) 	btrfs_put_root(root);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  77) 	if (IS_ERR(inode))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  78) 		return ERR_CAST(inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  79) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  80) 	if (check_generation && generation != inode->i_generation) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  81) 		iput(inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  82) 		return ERR_PTR(-ESTALE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  83) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  84) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  85) 	return d_obtain_alias(inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  86) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  87) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  88) static struct dentry *btrfs_fh_to_parent(struct super_block *sb, struct fid *fh,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  89) 					 int fh_len, int fh_type)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  90) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  91) 	struct btrfs_fid *fid = (struct btrfs_fid *) fh;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  92) 	u64 objectid, root_objectid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  93) 	u32 generation;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  94) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  95) 	if (fh_type == FILEID_BTRFS_WITH_PARENT) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  96) 		if (fh_len <  BTRFS_FID_SIZE_CONNECTABLE)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  97) 			return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  98) 		root_objectid = fid->root_objectid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  99) 	} else if (fh_type == FILEID_BTRFS_WITH_PARENT_ROOT) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) 		if (fh_len < BTRFS_FID_SIZE_CONNECTABLE_ROOT)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) 			return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) 		root_objectid = fid->parent_root_objectid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) 	} else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) 		return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) 	objectid = fid->parent_objectid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) 	generation = fid->parent_gen;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) 	return btrfs_get_dentry(sb, objectid, root_objectid, generation, 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) static struct dentry *btrfs_fh_to_dentry(struct super_block *sb, struct fid *fh,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) 					 int fh_len, int fh_type)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) 	struct btrfs_fid *fid = (struct btrfs_fid *) fh;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) 	u64 objectid, root_objectid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) 	u32 generation;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) 	if ((fh_type != FILEID_BTRFS_WITH_PARENT ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) 	     fh_len < BTRFS_FID_SIZE_CONNECTABLE) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) 	    (fh_type != FILEID_BTRFS_WITH_PARENT_ROOT ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) 	     fh_len < BTRFS_FID_SIZE_CONNECTABLE_ROOT) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) 	    (fh_type != FILEID_BTRFS_WITHOUT_PARENT ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) 	     fh_len < BTRFS_FID_SIZE_NON_CONNECTABLE))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) 		return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) 	objectid = fid->objectid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) 	root_objectid = fid->root_objectid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) 	generation = fid->gen;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) 	return btrfs_get_dentry(sb, objectid, root_objectid, generation, 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) struct dentry *btrfs_get_parent(struct dentry *child)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) 	struct inode *dir = d_inode(child);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) 	struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) 	struct btrfs_root *root = BTRFS_I(dir)->root;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) 	struct btrfs_path *path;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) 	struct extent_buffer *leaf;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) 	struct btrfs_root_ref *ref;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) 	struct btrfs_key key;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) 	struct btrfs_key found_key;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) 	int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) 	path = btrfs_alloc_path();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) 	if (!path)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) 		return ERR_PTR(-ENOMEM);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) 	if (btrfs_ino(BTRFS_I(dir)) == BTRFS_FIRST_FREE_OBJECTID) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) 		key.objectid = root->root_key.objectid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) 		key.type = BTRFS_ROOT_BACKREF_KEY;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) 		key.offset = (u64)-1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) 		root = fs_info->tree_root;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) 	} else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) 		key.objectid = btrfs_ino(BTRFS_I(dir));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) 		key.type = BTRFS_INODE_REF_KEY;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) 		key.offset = (u64)-1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) 	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) 	if (ret < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) 		goto fail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) 	BUG_ON(ret == 0); /* Key with offset of -1 found */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) 	if (path->slots[0] == 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) 		ret = -ENOENT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) 		goto fail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) 	path->slots[0]--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) 	leaf = path->nodes[0];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) 	btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) 	if (found_key.objectid != key.objectid || found_key.type != key.type) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) 		ret = -ENOENT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) 		goto fail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) 	if (found_key.type == BTRFS_ROOT_BACKREF_KEY) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) 		ref = btrfs_item_ptr(leaf, path->slots[0],
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) 				     struct btrfs_root_ref);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) 		key.objectid = btrfs_root_ref_dirid(leaf, ref);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) 	} else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) 		key.objectid = found_key.offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) 	btrfs_free_path(path);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) 	if (found_key.type == BTRFS_ROOT_BACKREF_KEY) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) 		return btrfs_get_dentry(fs_info->sb, key.objectid,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) 					found_key.offset, 0, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) 	return d_obtain_alias(btrfs_iget(fs_info->sb, key.objectid, root));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) fail:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) 	btrfs_free_path(path);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) 	return ERR_PTR(ret);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) static int btrfs_get_name(struct dentry *parent, char *name,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) 			  struct dentry *child)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) 	struct inode *inode = d_inode(child);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) 	struct inode *dir = d_inode(parent);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) 	struct btrfs_path *path;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) 	struct btrfs_root *root = BTRFS_I(dir)->root;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) 	struct btrfs_inode_ref *iref;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) 	struct btrfs_root_ref *rref;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) 	struct extent_buffer *leaf;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) 	unsigned long name_ptr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) 	struct btrfs_key key;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) 	int name_len;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) 	int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) 	u64 ino;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) 	if (!S_ISDIR(dir->i_mode))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) 		return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) 	ino = btrfs_ino(BTRFS_I(inode));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) 	path = btrfs_alloc_path();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) 	if (!path)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) 		return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) 	path->leave_spinning = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) 	if (ino == BTRFS_FIRST_FREE_OBJECTID) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) 		key.objectid = BTRFS_I(inode)->root->root_key.objectid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) 		key.type = BTRFS_ROOT_BACKREF_KEY;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) 		key.offset = (u64)-1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) 		root = fs_info->tree_root;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) 	} else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) 		key.objectid = ino;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) 		key.offset = btrfs_ino(BTRFS_I(dir));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) 		key.type = BTRFS_INODE_REF_KEY;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) 	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) 	if (ret < 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) 		btrfs_free_path(path);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) 		return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) 	} else if (ret > 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) 		if (ino == BTRFS_FIRST_FREE_OBJECTID) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) 			path->slots[0]--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) 		} else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) 			btrfs_free_path(path);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) 			return -ENOENT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) 	leaf = path->nodes[0];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) 	if (ino == BTRFS_FIRST_FREE_OBJECTID) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) 		rref = btrfs_item_ptr(leaf, path->slots[0],
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) 				     struct btrfs_root_ref);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) 		name_ptr = (unsigned long)(rref + 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) 		name_len = btrfs_root_ref_name_len(leaf, rref);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257) 	} else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258) 		iref = btrfs_item_ptr(leaf, path->slots[0],
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259) 				      struct btrfs_inode_ref);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260) 		name_ptr = (unsigned long)(iref + 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261) 		name_len = btrfs_inode_ref_name_len(leaf, iref);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) 	read_extent_buffer(leaf, name, name_ptr, name_len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265) 	btrfs_free_path(path);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268) 	 * have to add the null termination to make sure that reconnect_path
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) 	 * gets the right len for strlen
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271) 	name[name_len] = '\0';
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) const struct export_operations btrfs_export_ops = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) 	.encode_fh	= btrfs_encode_fh,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) 	.fh_to_dentry	= btrfs_fh_to_dentry,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279) 	.fh_to_parent	= btrfs_fh_to_parent,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) 	.get_parent	= btrfs_get_parent,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) 	.get_name	= btrfs_get_name,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282) };