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btrfs-progs: basic support for TREE_SEARCH_V2 ioctl 

Add the interface and helper that checks if the v2 ioctl is supported.

Signed-off-by: David Sterba <dsterba@suse.cz>
This commit is contained in:
David Sterba 2014-11-25 18:46:16 +01:00
parent 6715de04d9
commit 8ef9ac8cda
3 changed files with 56 additions and 0 deletions
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14
ioctl.h
View File

@ -279,6 +279,18 @@ struct btrfs_ioctl_search_args {
char buf[BTRFS_SEARCH_ARGS_BUFSIZE];
};
/*
* Extended version of TREE_SEARCH ioctl that can return more than 4k of bytes.
* The allocated size of the buffer is set in buf_size.
*/
struct btrfs_ioctl_search_args_v2 {
struct btrfs_ioctl_search_key key; /* in/out - search parameters */
__u64 buf_size; /* in - size of buffer
* out - on EOVERFLOW: needed size
* to store item */
__u64 buf[0]; /* out - found items */
};
#define BTRFS_INO_LOOKUP_PATH_MAX 4080
struct btrfs_ioctl_ino_lookup_args {
__u64 treeid;
@ -542,6 +554,8 @@ struct btrfs_ioctl_clone_range_args {
struct btrfs_ioctl_defrag_range_args)
#define BTRFS_IOC_TREE_SEARCH _IOWR(BTRFS_IOCTL_MAGIC, 17, \
struct btrfs_ioctl_search_args)
#define BTRFS_IOC_TREE_SEARCH_V2 _IOWR(BTRFS_IOCTL_MAGIC, 17, \
struct btrfs_ioctl_search_args_v2)
#define BTRFS_IOC_INO_LOOKUP _IOWR(BTRFS_IOCTL_MAGIC, 18, \
struct btrfs_ioctl_ino_lookup_args)
#define BTRFS_IOC_DEFAULT_SUBVOL _IOW(BTRFS_IOCTL_MAGIC, 19, __u64)

40
utils.c
View File

@ -2625,3 +2625,43 @@ u64 get_partition_size(char *dev)
return result;
}
int btrfs_tree_search2_ioctl_supported(int fd)
{
struct btrfs_ioctl_search_args_v2 *args2;
struct btrfs_ioctl_search_key *sk;
int args2_size = 1024;
char args2_buf[args2_size];
int ret;
static int v2_supported = -1;
if (v2_supported != -1)
return v2_supported;
args2 = (struct btrfs_ioctl_search_args_v2 *)args2_buf;
sk = &(args2->key);
/*
* Search for the extent tree item in the root tree.
*/
sk->tree_id = BTRFS_ROOT_TREE_OBJECTID;
sk->min_objectid = BTRFS_EXTENT_TREE_OBJECTID;
sk->max_objectid = BTRFS_EXTENT_TREE_OBJECTID;
sk->min_type = BTRFS_ROOT_ITEM_KEY;
sk->max_type = BTRFS_ROOT_ITEM_KEY;
sk->min_offset = 0;
sk->max_offset = (u64)-1;
sk->min_transid = 0;
sk->max_transid = (u64)-1;
sk->nr_items = 1;
args2->buf_size = args2_size - sizeof(struct btrfs_ioctl_search_args_v2);
ret = ioctl(fd, BTRFS_IOC_TREE_SEARCH_V2, args2);
if (ret == -EOPNOTSUPP)
v2_supported = 0;
else if (ret == 0)
v2_supported = 1;
else
return ret;
return v2_supported;
}

2
utils.h
View File

@ -187,4 +187,6 @@ static inline int count_digits(u64 num)
return ret;
}
int btrfs_tree_search2_ioctl_supported(int fd);
#endif