Gitweb: http://git.fedorahosted.org/git/?p=lvm2.git;a=commitdiff;h=1f30e5a0522a69aac... Commit: 1f30e5a0522a69aac0d246d2fb4e5ce2f6872cff Parent: d96b854ac054aafc8a9981016faefb9f122fccbb Author: Zdenek Kabelac zkabelac@redhat.com AuthorDate: Thu May 16 11:34:26 2013 +0200 Committer: Zdenek Kabelac zkabelac@redhat.com CommitterDate: Mon May 20 16:28:30 2013 +0200
libdm: introduce dm_mountinfo_read
Add function for parsing /proc/self/mountinfo entries. This can be used to detected mounted device. --- WHATS_NEW_DM | 1 + libdm/libdevmapper.h | 13 ++++++++ libdm/libdm-common.c | 77 ++++++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 91 insertions(+), 0 deletions(-)
diff --git a/WHATS_NEW_DM b/WHATS_NEW_DM index 39ebcb2..8bdbfab 100644 --- a/WHATS_NEW_DM +++ b/WHATS_NEW_DM @@ -1,5 +1,6 @@ Version 1.02.78 - =================================== + Add dm_mountinfo_read() for parsing /proc/self/mountinfo. Report error for nonexisting devices in dmeventd communication. Prevent double free error after dmeventd call of _fill_device_data(). Update dmevent structure message_data to simplify/fix error path handling. diff --git a/libdm/libdevmapper.h b/libdm/libdevmapper.h index b729846..d9cd280 100644 --- a/libdm/libdevmapper.h +++ b/libdm/libdevmapper.h @@ -417,6 +417,19 @@ int dm_device_has_mounted_fs(uint32_t major, uint32_t minor);
/* + * Callback is invoked for individal mountinfo lines, + * minor, major and mount target are parsed and unmangled. + */ +typedef int (*dm_mountinfo_line_callback_fn) (char *line, unsigned maj, unsigned min, + char *target, void *cb_data); + +/* + * Read all lines from /proc/self/mountinfo, + * for each line calls read_fn callback. + */ +int dm_mountinfo_read(dm_mountinfo_line_callback_fn read_fn, void *cb_data); + +/* * Initialise library */ void dm_lib_init(void) __attribute__((constructor)); diff --git a/libdm/libdm-common.c b/libdm/libdm-common.c index 4736b59..9e8ca25 100644 --- a/libdm/libdm-common.c +++ b/libdm/libdm-common.c @@ -62,6 +62,7 @@ union semun static char _dm_dir[PATH_MAX] = DEV_DIR DM_DIR; static char _sysfs_dir[PATH_MAX] = "/sys/"; static char _path0[PATH_MAX]; /* path buffer, safe 4kB on stack */ +static const char _mountinfo[] = "/proc/self/mountinfo";
#define DM_MAX_UUID_PREFIX_LEN 15 static char _default_uuid_prefix[DM_MAX_UUID_PREFIX_LEN + 1] = "LVM-"; @@ -1571,6 +1572,82 @@ const char *dm_uuid_prefix(void) return _default_uuid_prefix; }
+static int _is_octal(int a) +{ + return (((a) & ~7) == '0'); +} + +/* Convert mangled mountinfo into normal ASCII string */ +static void _unmangle_mountinfo_string(const char *src, char *buf) +{ + while (*src) { + if ((*src == '\') && + _is_octal(src[1]) && _is_octal(src[2]) && _is_octal(src[3])) { + *buf++ = 64 * (src[1] & 7) + 8 * (src[2] & 7) + (src[3] & 7); + src += 4; + } else + *buf++ = *src++; + } + *buf = '\0'; +} + +/* Macros to make string defines */ +#define TO_STRING_EXP(A) #A +#define TO_STRING(A) TO_STRING_EXP(A) + +/* Parse one line of mountinfo and unmangled target line */ +static int _mountinfo_parse_line(const char *line, unsigned *maj, unsigned *min, char *buf) +{ + char root[PATH_MAX + 1]; + char target[PATH_MAX + 1]; + + /* TODO: maybe detect availability of %ms glib support ? */ + if (sscanf(line, "%*u %*u %u:%u %" TO_STRING(PATH_MAX) + "s %" TO_STRING(PATH_MAX) "s", + maj, min, root, target) < 4) { + log_error("Failed to parse mountinfo line."); + return 0; + } + + _unmangle_mountinfo_string(target, buf); + + return 1; +} + +/* + * Function to operate on individal mountinfo line, + * minor, major and mount target are parsed and unmangled + */ +int dm_mountinfo_read(dm_mountinfo_line_callback_fn read_fn, void *cb_data) +{ + FILE *minfo; + char buffer[2 * PATH_MAX]; + char target[PATH_MAX]; + unsigned maj, min; + int r = 1; + + if (!(minfo = fopen(_mountinfo, "r"))) { + if (errno != ENOENT) + log_sys_error("fopen", _mountinfo); + else + log_sys_debug("fopen", _mountinfo); + return 0; + } + + while (!feof(minfo) && fgets(buffer, sizeof(buffer), minfo)) + if (!_mountinfo_parse_line(buffer, &maj, &min, target) || + !read_fn(buffer, maj, min, target, cb_data)) { + stack; + r = 0; + break; + } + + if (fclose(minfo)) + log_sys_error("fclose", _mountinfo); + + return r; +} + static int _sysfs_get_dm_name(uint32_t major, uint32_t minor, char *buf, size_t buf_size) { char *sysfs_path, *temp_buf = NULL;
lvm2-commits@lists.fedorahosted.org