From 8ef9ac8cda38bda25561c2964f0aa81d8dcdf451 Mon Sep 17 00:00:00 2001 From: David Sterba Date: Tue, 25 Nov 2014 18:46:16 +0100 Subject: [PATCH] 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 --- ioctl.h | 14 ++++++++++++++ utils.c | 40 ++++++++++++++++++++++++++++++++++++++++ utils.h | 2 ++ 3 files changed, 56 insertions(+) diff --git a/ioctl.h b/ioctl.h index 67c8de98..2c2c7c1b 100644 --- a/ioctl.h +++ b/ioctl.h @@ -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) diff --git a/utils.c b/utils.c index 88856695..1dba1821 100644 --- a/utils.c +++ b/utils.c @@ -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; +} diff --git a/utils.h b/utils.h index 6cbb7b89..0464c2da 100644 --- a/utils.h +++ b/utils.h @@ -187,4 +187,6 @@ static inline int count_digits(u64 num) return ret; } +int btrfs_tree_search2_ioctl_supported(int fd); + #endif