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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 14:54:37 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 14:54:37 +0000 |
commit | 97c26c1924b076ef23ebe4381558e8aa025712b2 (patch) | |
tree | 109724175f07436696f51b14b5abbd3f4d704d6d /libmisc/btrfs.c | |
parent | Initial commit. (diff) | |
download | shadow-97c26c1924b076ef23ebe4381558e8aa025712b2.tar.xz shadow-97c26c1924b076ef23ebe4381558e8aa025712b2.zip |
Adding upstream version 1:4.13+dfsg1.upstream/1%4.13+dfsg1upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'libmisc/btrfs.c')
-rw-r--r-- | libmisc/btrfs.c | 110 |
1 files changed, 110 insertions, 0 deletions
diff --git a/libmisc/btrfs.c b/libmisc/btrfs.c new file mode 100644 index 0000000..a2563f7 --- /dev/null +++ b/libmisc/btrfs.c @@ -0,0 +1,110 @@ +#include <linux/btrfs_tree.h> +#include <linux/magic.h> +#include <sys/statfs.h> +#include <stdbool.h> + +#include "prototypes.h" + +static bool path_exists(const char *p) +{ + struct stat sb; + + return stat(p, &sb) == 0; +} + +static const char *btrfs_cmd(void) +{ + const char *const btrfs_paths[] = {"/sbin/btrfs", + "/bin/btrfs", "/usr/sbin/btrfs", "/usr/bin/btrfs", NULL}; + const char *p; + int i; + + for (i = 0, p = btrfs_paths[i]; p; i++, p = btrfs_paths[i]) + if (path_exists(p)) + return p; + + return NULL; +} + +static int run_btrfs_subvolume_cmd(const char *subcmd, const char *arg1, const char *arg2) +{ + int status = 0; + const char *cmd = btrfs_cmd(); + const char *argv[] = { + "btrfs", + "subvolume", + subcmd, + arg1, + arg2, + NULL + }; + + if (access(cmd, X_OK)) { + return 1; + } + + if (run_command(cmd, argv, NULL, &status)) + return -1; + return status; +} + + +int btrfs_create_subvolume(const char *path) +{ + return run_btrfs_subvolume_cmd("create", path, NULL); +} + + +int btrfs_remove_subvolume(const char *path) +{ + return run_btrfs_subvolume_cmd("delete", "-C", path); +} + + +/* Adapted from btrfsprogs */ +/* + * This intentionally duplicates btrfs_util_is_subvolume_fd() instead of opening + * a file descriptor and calling it, because fstat() and fstatfs() don't accept + * file descriptors opened with O_PATH on old kernels (before v3.6 and before + * v3.12, respectively), but stat() and statfs() can be called on a path that + * the user doesn't have read or write permissions to. + * + * returns: + * 1 - btrfs subvolume + * 0 - not btrfs subvolume + * -1 - error + */ +int btrfs_is_subvolume(const char *path) +{ + struct stat st; + int ret; + + ret = is_btrfs(path); + if (ret <= 0) + return ret; + + ret = stat(path, &st); + if (ret == -1) + return -1; + + if (st.st_ino != BTRFS_FIRST_FREE_OBJECTID || !S_ISDIR(st.st_mode)) { + return 0; + } + + return 1; +} + + +/* Adapted from btrfsprogs */ +int is_btrfs(const char *path) +{ + struct statfs sfs; + int ret; + + ret = statfs(path, &sfs); + if (ret == -1) + return -1; + + return sfs.f_type == BTRFS_SUPER_MAGIC; +} + |