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author | Petr Rockai <prockai@redhat.com> | 2010-10-29 16:43:51 +0000 |
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committer | Petr Rockai <prockai@redhat.com> | 2010-10-29 16:43:51 +0000 |
commit | fe9ac4d3f4e4d5b8153189bd3b2ecc2c8385e977 (patch) | |
tree | e490b0296000b56e8c74a5dc65ac6215d8ee6320 /daemons/dmeventd | |
parent | 63b8dfbde70f61cf318df70f83b078e28115faca (diff) | |
download | lvm2-fe9ac4d3f4e4d5b8153189bd3b2ecc2c8385e977.tar.gz lvm2-fe9ac4d3f4e4d5b8153189bd3b2ecc2c8385e977.tar.xz lvm2-fe9ac4d3f4e4d5b8153189bd3b2ecc2c8385e977.zip |
Add code to the dmeventd snapshot plugin to automatically unmount snapshots
that have been invalidated.
Diffstat (limited to 'daemons/dmeventd')
-rw-r--r-- | daemons/dmeventd/plugins/snapshot/dmeventd_snapshot.c | 89 |
1 files changed, 89 insertions, 0 deletions
diff --git a/daemons/dmeventd/plugins/snapshot/dmeventd_snapshot.c b/daemons/dmeventd/plugins/snapshot/dmeventd_snapshot.c index e3d0b4eb..00fc4362 100644 --- a/daemons/dmeventd/plugins/snapshot/dmeventd_snapshot.c +++ b/daemons/dmeventd/plugins/snapshot/dmeventd_snapshot.c @@ -21,6 +21,7 @@ #include "lvm-string.h" +#include <sys/wait.h> #include <syslog.h> /* FIXME Replace syslog with multilog */ /* FIXME Missing openlog? */ @@ -31,6 +32,8 @@ /* Do not bother checking snapshots less than 50% full. */ #define CHECK_MINIMUM 50 +#define UMOUNT_COMMAND "/bin/umount" + struct snap_status { int invalid; int used; @@ -71,6 +74,47 @@ static void _parse_snapshot_params(char *params, struct snap_status *status) status->max = atoi(p); } +static int _run(const char *cmd, ...) +{ + va_list ap; + int argc = 1; /* for argv[0], i.e. cmd */ + int i = 0; + const char **argv; + pid_t pid = fork(); + int status; + + if (pid == 0) { /* child */ + va_start(ap, cmd); + while (va_arg(ap, const char *)) + ++ argc; + va_end(ap); + + /* + 1 for the terminating NULL */ + argv = alloca(sizeof(const char *) * (argc + 1)); + + argv[0] = cmd; + va_start(ap, cmd); + while ((argv[++i] = va_arg(ap, const char *))); + va_end(ap); + + execvp(cmd, (char **)argv); + syslog(LOG_ERR, "Failed to execute %s: %s.\n", cmd, strerror(errno)); + exit(127); + } + + if (pid > 0) { /* parent */ + if (waitpid(pid, &status, 0) != pid) + return 0; /* waitpid failed */ + if (!WIFEXITED(status) || WEXITSTATUS(status)) + return 0; /* the child failed */ + } + + if (pid < 0) + return 0; /* fork failed */ + + return 1; /* all good */ +} + static int _extend(const char *device) { char *vg = NULL, *lv = NULL, *layer = NULL; @@ -93,6 +137,41 @@ static int _extend(const char *device) return r == ECMD_PROCESSED; } +static void _umount(const char *device, int major, int minor) +{ + FILE *mounts; + char buffer[4096]; + char *words[3]; + struct stat st; + + if (!(mounts = fopen("/proc/mounts", "r"))) { + syslog(LOG_ERR, "Could not read /proc/mounts. Not umounting %s.\n", device); + return; + } + + while (!feof(mounts)) { + /* read a line of /proc/mounts */ + if (!fgets(buffer, sizeof(buffer), mounts)) + break; /* eof, likely */ + + /* words[0] is the mount point and words[1] is the device path */ + dm_split_words(buffer, 3, 0, words); + + /* find the major/minor of the device */ + if (stat(words[0], &st)) + continue; /* can't stat, skip this one */ + + if (S_ISBLK(st.st_mode) && + major(st.st_rdev) == major && + minor(st.st_rdev) == minor) { + syslog(LOG_ERR, "Unmounting invalid snapshot %s from %s.", device, words[1]); + if (!_run(UMOUNT_COMMAND, "-fl", words[1], NULL)) + syslog(LOG_ERR, "Failed to umount snapshot %s from %s: %s.", + device, words[1], strerror(errno)); + } + } +} + void process_event(struct dm_task *dmt, enum dm_event_mask event __attribute__((unused)), void **private) @@ -117,6 +196,16 @@ void process_event(struct dm_task *dmt, _parse_snapshot_params(params, &status); + if (status.invalid) { + syslog(LOG_ERR, "Trying to umount invalid snapshot %s...\n", device); + struct dm_info info; + if (dm_task_get_info(dmt, &info)) { + dmeventd_lvm2_unlock(); + _umount(device, info.major, info.minor); + return; + } /* else; too bad, but this is best-effort thing... */ + } + /* * If the snapshot has been invalidated or we failed to parse * the status string. Report the full status string to syslog. |