Release 4.11 fs/btrfs/export.c

#include <linux/fs.h>
#include <linux/types.h>
#include "ctree.h"
#include "disk-io.h"
#include "btrfs_inode.h"
#include "print-tree.h"
#include "export.h"


#define BTRFS_FID_SIZE_NON_CONNECTABLE (offsetof(struct btrfs_fid, \
                                                 parent_objectid) / 4)

#define BTRFS_FID_SIZE_CONNECTABLE (offsetof(struct btrfs_fid, \
                                             parent_root_objectid) / 4)

#define BTRFS_FID_SIZE_CONNECTABLE_ROOT (sizeof(struct btrfs_fid) / 4)



static int btrfs_encode_fh(struct inode *inode, u32 *fh, int *max_len,
			   struct inode *parent)
{
	struct btrfs_fid *fid = (struct btrfs_fid *)fh;
	int len = *max_len;
	int type;

	if (parent && (len < BTRFS_FID_SIZE_CONNECTABLE)) {
		*max_len = BTRFS_FID_SIZE_CONNECTABLE;
		return FILEID_INVALID;
	} else if (len < BTRFS_FID_SIZE_NON_CONNECTABLE) {
		*max_len = BTRFS_FID_SIZE_NON_CONNECTABLE;
		return FILEID_INVALID;
	}

	len  = BTRFS_FID_SIZE_NON_CONNECTABLE;
	type = FILEID_BTRFS_WITHOUT_PARENT;

	fid->objectid = btrfs_ino(BTRFS_I(inode));
	fid->root_objectid = BTRFS_I(inode)->root->objectid;
	fid->gen = inode->i_generation;

	if (parent) {
		u64 parent_root_id;

		fid->parent_objectid = BTRFS_I(parent)->location.objectid;
		fid->parent_gen = parent->i_generation;
		parent_root_id = BTRFS_I(parent)->root->objectid;

		if (parent_root_id != fid->root_objectid) {
			fid->parent_root_objectid = parent_root_id;
			len = BTRFS_FID_SIZE_CONNECTABLE_ROOT;
			type = FILEID_BTRFS_WITH_PARENT_ROOT;
		} else {
			len = BTRFS_FID_SIZE_CONNECTABLE;
			type = FILEID_BTRFS_WITH_PARENT;
		}
	}

	*max_len = len;
	return type;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Balaji Rao
167
80.68%
1
16.67%
Aneesh Kumar K.V
24
11.59%
1
16.67%
Al Viro
8
3.86%
1
16.67%
Nikolay Borisov
3
1.45%
1
16.67%
Li Zefan
3
1.45%
1
16.67%
Namjae Jeon
2
0.97%
1
16.67%
Total
207
100.00%
6
100.00%



static struct dentry *btrfs_get_dentry(struct super_block *sb, u64 objectid,
				       u64 root_objectid, u32 generation,
				       int check_generation)
{
	struct btrfs_fs_info *fs_info = btrfs_sb(sb);
	struct btrfs_root *root;
	struct inode *inode;
	struct btrfs_key key;
	int index;
	int err = 0;

	if (objectid < BTRFS_FIRST_FREE_OBJECTID)
		return ERR_PTR(-ESTALE);

	key.objectid = root_objectid;
	key.type = BTRFS_ROOT_ITEM_KEY;
	key.offset = (u64)-1;

	index = srcu_read_lock(&fs_info->subvol_srcu);

	root = btrfs_read_fs_root_no_name(fs_info, &key);
	if (IS_ERR(root)) {
		err = PTR_ERR(root);
		goto fail;
	}

	key.objectid = objectid;
	key.type = BTRFS_INODE_ITEM_KEY;
	key.offset = 0;

	inode = btrfs_iget(sb, &key, root, NULL);
	if (IS_ERR(inode)) {
		err = PTR_ERR(inode);
		goto fail;
	}

	srcu_read_unlock(&fs_info->subvol_srcu, index);

	if (check_generation && generation != inode->i_generation) {
		iput(inode);
		return ERR_PTR(-ESTALE);
	}

	return d_obtain_alias(inode);
fail:
	srcu_read_unlock(&fs_info->subvol_srcu, index);
	return ERR_PTR(err);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Balaji Rao
102
42.50%
1
16.67%
Zheng Yan
94
39.17%
1
16.67%
David Woodhouse
35
14.58%
1
16.67%
David Sterba
6
2.50%
1
16.67%
Josef Bacik
2
0.83%
1
16.67%
Al Viro
1
0.42%
1
16.67%
Total
240
100.00%
6
100.00%



static struct dentry *btrfs_fh_to_parent(struct super_block *sb, struct fid *fh,
					 int fh_len, int fh_type)
{
	struct btrfs_fid *fid = (struct btrfs_fid *) fh;
	u64 objectid, root_objectid;
	u32 generation;

	if (fh_type == FILEID_BTRFS_WITH_PARENT) {
		if (fh_len <  BTRFS_FID_SIZE_CONNECTABLE)
			return NULL;
		root_objectid = fid->root_objectid;
	} else if (fh_type == FILEID_BTRFS_WITH_PARENT_ROOT) {
		if (fh_len < BTRFS_FID_SIZE_CONNECTABLE_ROOT)
			return NULL;
		root_objectid = fid->parent_root_objectid;
	} else
		return NULL;

	objectid = fid->parent_objectid;
	generation = fid->parent_gen;

	return btrfs_get_dentry(sb, objectid, root_objectid, generation, 1);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Balaji Rao
117
96.69%
1
33.33%
Zheng Yan
2
1.65%
1
33.33%
Neil Brown
2
1.65%
1
33.33%
Total
121
100.00%
3
100.00%



static struct dentry *btrfs_fh_to_dentry(struct super_block *sb, struct fid *fh,
					 int fh_len, int fh_type)
{
	struct btrfs_fid *fid = (struct btrfs_fid *) fh;
	u64 objectid, root_objectid;
	u32 generation;

	if ((fh_type != FILEID_BTRFS_WITH_PARENT ||
	     fh_len < BTRFS_FID_SIZE_CONNECTABLE) &&
	    (fh_type != FILEID_BTRFS_WITH_PARENT_ROOT ||
	     fh_len < BTRFS_FID_SIZE_CONNECTABLE_ROOT) &&
	    (fh_type != FILEID_BTRFS_WITHOUT_PARENT ||
	     fh_len < BTRFS_FID_SIZE_NON_CONNECTABLE))
		return NULL;

	objectid = fid->objectid;
	root_objectid = fid->root_objectid;
	generation = fid->gen;

	return btrfs_get_dentry(sb, objectid, root_objectid, generation, 1);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Balaji Rao
106
95.50%
1
33.33%
Neil Brown
3
2.70%
1
33.33%
Zheng Yan
2
1.80%
1
33.33%
Total
111
100.00%
3
100.00%



static struct dentry *btrfs_get_parent(struct dentry *child)
{
	struct inode *dir = d_inode(child);
	struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
	struct btrfs_root *root = BTRFS_I(dir)->root;
	struct btrfs_path *path;
	struct extent_buffer *leaf;
	struct btrfs_root_ref *ref;
	struct btrfs_key key;
	struct btrfs_key found_key;
	int ret;

	path = btrfs_alloc_path();
	if (!path)
		return ERR_PTR(-ENOMEM);

	if (btrfs_ino(BTRFS_I(dir)) == BTRFS_FIRST_FREE_OBJECTID) {
		key.objectid = root->root_key.objectid;
		key.type = BTRFS_ROOT_BACKREF_KEY;
		key.offset = (u64)-1;
		root = fs_info->tree_root;
	} else {
		key.objectid = btrfs_ino(BTRFS_I(dir));
		key.type = BTRFS_INODE_REF_KEY;
		key.offset = (u64)-1;
	}

	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
	if (ret < 0)
		goto fail;

	BUG_ON(ret == 0); /* Key with offset of -1 found */
	if (path->slots[0] == 0) {
		ret = -ENOENT;
		goto fail;
	}

	path->slots[0]--;
	leaf = path->nodes[0];

	btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
	if (found_key.objectid != key.objectid || found_key.type != key.type) {
		ret = -ENOENT;
		goto fail;
	}

	if (found_key.type == BTRFS_ROOT_BACKREF_KEY) {
		ref = btrfs_item_ptr(leaf, path->slots[0],
				     struct btrfs_root_ref);
		key.objectid = btrfs_root_ref_dirid(leaf, ref);
	} else {
		key.objectid = found_key.offset;
	}
	btrfs_free_path(path);

	if (found_key.type == BTRFS_ROOT_BACKREF_KEY) {
		return btrfs_get_dentry(fs_info->sb, key.objectid,
					found_key.offset, 0, 0);
	}

	key.type = BTRFS_INODE_ITEM_KEY;
	key.offset = 0;
	return d_obtain_alias(btrfs_iget(fs_info->sb, &key, root, NULL));
fail:
	btrfs_free_path(path);
	return ERR_PTR(ret);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Zheng Yan
192
46.83%
1
7.14%
Balaji Rao
138
33.66%
1
7.14%
David Woodhouse
35
8.54%
3
21.43%
Jeff Mahoney
13
3.17%
2
14.29%
Liu Bo
12
2.93%
1
7.14%
Nikolay Borisov
6
1.46%
1
7.14%
Li Zefan
6
1.46%
1
7.14%
David Howells
3
0.73%
1
7.14%
Josef Bacik
2
0.49%
1
7.14%
Christoph Hellwig
2
0.49%
1
7.14%
Al Viro
1
0.24%
1
7.14%
Total
410
100.00%
14
100.00%



static int btrfs_get_name(struct dentry *parent, char *name,
			  struct dentry *child)
{
	struct inode *inode = d_inode(child);
	struct inode *dir = d_inode(parent);
	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
	struct btrfs_path *path;
	struct btrfs_root *root = BTRFS_I(dir)->root;
	struct btrfs_inode_ref *iref;
	struct btrfs_root_ref *rref;
	struct extent_buffer *leaf;
	unsigned long name_ptr;
	struct btrfs_key key;
	int name_len;
	int ret;
	u64 ino;

	if (!S_ISDIR(dir->i_mode))
		return -EINVAL;

	ino = btrfs_ino(BTRFS_I(inode));

	path = btrfs_alloc_path();
	if (!path)
		return -ENOMEM;
	path->leave_spinning = 1;

	if (ino == BTRFS_FIRST_FREE_OBJECTID) {
		key.objectid = BTRFS_I(inode)->root->root_key.objectid;
		key.type = BTRFS_ROOT_BACKREF_KEY;
		key.offset = (u64)-1;
		root = fs_info->tree_root;
	} else {
		key.objectid = ino;
		key.offset = btrfs_ino(BTRFS_I(dir));
		key.type = BTRFS_INODE_REF_KEY;
	}

	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
	if (ret < 0) {
		btrfs_free_path(path);
		return ret;
	} else if (ret > 0) {
		if (ino == BTRFS_FIRST_FREE_OBJECTID) {
			path->slots[0]--;
		} else {
			btrfs_free_path(path);
			return -ENOENT;
		}
	}
	leaf = path->nodes[0];

	if (ino == BTRFS_FIRST_FREE_OBJECTID) {
		rref = btrfs_item_ptr(leaf, path->slots[0],
				     struct btrfs_root_ref);
		name_ptr = (unsigned long)(rref + 1);
		name_len = btrfs_root_ref_name_len(leaf, rref);
	} else {
		iref = btrfs_item_ptr(leaf, path->slots[0],
				      struct btrfs_inode_ref);
		name_ptr = (unsigned long)(iref + 1);
		name_len = btrfs_inode_ref_name_len(leaf, iref);
	}

	read_extent_buffer(leaf, name, name_ptr, name_len);
	btrfs_free_path(path);

	/*
         * have to add the null termination to make sure that reconnect_path
         * gets the right len for strlen
         */
	name[name_len] = '\0';

	return 0;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Josef Bacik
370
90.02%
1
20.00%
Li Zefan
17
4.14%
1
20.00%
Jeff Mahoney
12
2.92%
1
20.00%
Nikolay Borisov
6
1.46%
1
20.00%
David Howells
6
1.46%
1
20.00%
Total
411
100.00%
5
100.00%


const struct export_operations btrfs_export_ops = {
	.encode_fh	= btrfs_encode_fh,
	.fh_to_dentry	= btrfs_fh_to_dentry,
	.fh_to_parent	= btrfs_fh_to_parent,
	.get_parent	= btrfs_get_parent,
	.get_name	= btrfs_get_name,
};
Overall Contributors
Person
Tokens
Prop
Commits
CommitProp
Balaji Rao
687
43.90%
1
4.76%
Josef Bacik
379
24.22%
2
9.52%
Zheng Yan
290
18.53%
1
4.76%
David Woodhouse
70
4.47%
3
14.29%
Li Zefan
26
1.66%
1
4.76%
Jeff Mahoney
25
1.60%
2
9.52%
Aneesh Kumar K.V
24
1.53%
1
4.76%
Nikolay Borisov
15
0.96%
1
4.76%
Liu Bo
12
0.77%
1
4.76%
Al Viro
10
0.64%
2
9.52%
David Howells
9
0.58%
1
4.76%
David Sterba
6
0.38%
1
4.76%
Neil Brown
5
0.32%
1
4.76%
Chris Mason
3
0.19%
1
4.76%
Namjae Jeon
2
0.13%
1
4.76%
Christoph Hellwig
2
0.13%
1
4.76%
Total
1565
100.00%
21
100.00%
Directory: fs/btrfs

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