Refactor init(8) atexit handling.
This commit is contained in:
Jonas 'Sortie' Termansen
parent
fdfe16ad30
commit
0b07e62259
106
init/init.c
106
init/init.c
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@ -53,6 +53,35 @@
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#include <mount/partition.h>
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#include <mount/uuid.h>
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struct device_match
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{
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const char* path;
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struct blockdevice* bdev;
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};
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struct mountpoint
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{
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struct fstab entry;
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char* entry_line;
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pid_t pid;
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char* absolute;
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};
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static pid_t main_pid;
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static struct harddisk** hds = NULL;
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static size_t hds_used = 0;
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static size_t hds_length = 0;
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static struct mountpoint* mountpoints = NULL;
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static size_t mountpoints_used = 0;
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static size_t mountpoints_length = 0;
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static bool chain_location_made = false;
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static char chain_location[] = "/tmp/fs.XXXXXX";
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static bool chain_location_dev_made = false;
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static char chain_location_dev[] = "/tmp/fs.XXXXXX/dev";
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static char* read_single_line(FILE* fp)
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{
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char* ret = NULL;
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@ -79,8 +108,6 @@ static char* join_paths(const char* a, const char* b)
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return result;
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}
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static pid_t main_pid;
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__attribute__((noreturn))
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__attribute__((format(printf, 1, 2)))
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static void fatal(const char* format, ...)
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@ -121,10 +148,6 @@ static void note(const char* format, ...)
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va_end(ap);
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}
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static struct harddisk** hds = NULL;
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static size_t hds_used = 0;
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static size_t hds_length = 0;
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static void prepare_filesystem(const char* path, struct blockdevice* bdev)
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{
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enum filesystem_error fserr = blockdevice_inspect_filesystem(&bdev->fs, bdev);
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@ -233,12 +256,6 @@ static void prepare_block_devices(void)
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fatal("iterating devices: %m");
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}
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struct device_match
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{
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const char* path;
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struct blockdevice* bdev;
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};
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static void search_by_uuid(const char* uuid_string,
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void (*cb)(void*, struct device_match*),
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void* ctx)
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@ -295,18 +312,6 @@ static void ensure_single_device_match(void* ctx, struct device_match* match)
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*result = *match;
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}
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struct mountpoint
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{
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struct fstab entry;
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char* entry_line;
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pid_t pid;
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char* absolute;
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};
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static struct mountpoint* mountpoints = NULL;
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static size_t mountpoints_used = 0;
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static size_t mountpoints_length = 0;
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static int sort_mountpoint(const void* a_ptr, const void* b_ptr)
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{
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const struct mountpoint* a = (const struct mountpoint*) a_ptr;
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@ -704,6 +709,29 @@ static void mountpoints_unmount(void)
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}
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}
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// This function must be usable as an atexit handler, which means it is
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// undefined behavior for it to invoke exit(), including through calls to fatal
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// in any function transitively called by this function.
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static void niht(void)
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{
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if ( getpid() != main_pid )
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return;
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if ( chain_location_dev_made )
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{
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unmount(chain_location_dev, 0);
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chain_location_dev_made = false;
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}
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mountpoints_unmount();
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if ( chain_location_made )
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{
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rmdir(chain_location);
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chain_location_made = false;
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}
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}
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static int init(const char* target)
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{
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init_early();
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@ -712,8 +740,6 @@ static int init(const char* target)
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set_videomode();
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prepare_block_devices();
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load_fstab();
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if ( atexit(mountpoints_unmount) != 0 )
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fatal("atexit: %m");
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mountpoints_mount(false);
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sigset_t oldset, sigttou;
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sigemptyset(&sigttou);
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@ -800,35 +826,14 @@ static int init(const char* target)
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else
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note("session: Unexpected unusual termination%s", back);
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}
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mountpoints_unmount();
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return result;
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}
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static bool chain_location_made = false;
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static char chain_location[] = "/tmp/fs.XXXXXX";
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static bool chain_location_dev_made = false;
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static char chain_location_dev[] = "/tmp/fs.XXXXXX/dev";
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static void init_chain_atexit(void)
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{
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if ( chain_location_dev_made )
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{
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unmount(chain_location_dev, 0);
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chain_location_dev_made = false;
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}
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if ( chain_location_made )
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{
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rmdir(chain_location);
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chain_location_made = false;
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}
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}
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static int init_chain(const char* target)
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{
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init_early();
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prepare_block_devices();
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load_fstab();
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if ( atexit(init_chain_atexit) != 0 )
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fatal("atexit: %m");
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if ( !mkdtemp(chain_location) )
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fatal("mkdtemp: /tmp/fs.XXXXXX: %m");
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chain_location_made = true;
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@ -844,8 +849,6 @@ static int init_chain(const char* target)
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}
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if ( !found_root )
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fatal("/etc/fstab: Root filesystem not found in filesystem table");
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if ( atexit(mountpoints_unmount) != 0 )
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fatal("atexit: %m");
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mountpoints_mount(true);
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snprintf(chain_location_dev, sizeof(chain_location_dev), "%s/dev",
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chain_location);
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@ -917,8 +920,6 @@ static int init_chain(const char* target)
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else
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note("chain init: Unexpected unusual termination%s", back);
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}
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mountpoints_unmount();
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init_chain_atexit();
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return result;
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}
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@ -997,6 +998,9 @@ int main(int argc, char* argv[])
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if ( getenv("INIT_PID") )
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fatal("System is already managed by an init process");
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if ( atexit(niht) != 0 )
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fatal("atexit: %m");
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if ( !strcmp(target, "single-user") ||
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!strcmp(target, "multi-user") ||
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!strcmp(target, "sysinstall") ||
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