fs/gfs2/lock_dlm.c

Source file repositories/reference/linux-study-clean/fs/gfs2/lock_dlm.c

File Facts

System
Linux kernel
Corpus path
fs/gfs2/lock_dlm.c
Extension
.c
Size
43123 bytes
Lines
1463
Domain
Core OS
Bucket
VFS And Filesystem Core
Inferred role
Core OS: implementation source
Status
source implementation candidate

Why This File Exists

Core operating-system implementation surface: boot, tasks, memory, VFS, syscall-facing interfaces, synchronization, credentials, and isolation.

Dependency Surface

Detected Declarations

Annotated Snippet

test_bit(DFL_FIRST_MOUNT, &ls->ls_recover_flags)) {
		spin_unlock(&ls->ls_recover_spin);
		return;
	}
	block_gen = ls->ls_recover_block;
	start_gen = ls->ls_recover_start;
	spin_unlock(&ls->ls_recover_spin);

	/*
	 * Equal block_gen and start_gen implies we are between
	 * recover_prep and recover_done callbacks, which means
	 * dlm recovery is in progress and dlm locking is blocked.
	 * There's no point trying to do any work until recover_done.
	 */

	if (block_gen == start_gen)
		return;

	/*
	 * Propagate recover_submit[] and recover_result[] to lvb:
	 * dlm_recoverd adds to recover_submit[] jids needing recovery
	 * gfs2_recover adds to recover_result[] journal recovery results
	 *
	 * set lvb bit for jids in recover_submit[] if the lvb has not
	 * yet been updated for the generation of the failure
	 *
	 * clear lvb bit for jids in recover_result[] if the result of
	 * the journal recovery is SUCCESS
	 */

	error = control_lock(sdp, DLM_LOCK_EX, DLM_LKF_CONVERT|DLM_LKF_VALBLK);
	if (error) {
		fs_err(sdp, "control lock EX error %d\n", error);
		return;
	}

	control_lvb_read(ls, &lvb_gen, ls->ls_lvb_bits);

	spin_lock(&ls->ls_recover_spin);
	if (block_gen != ls->ls_recover_block ||
	    start_gen != ls->ls_recover_start) {
		fs_info(sdp, "recover generation %u block1 %u %u\n",
			start_gen, block_gen, ls->ls_recover_block);
		spin_unlock(&ls->ls_recover_spin);
		control_lock(sdp, DLM_LOCK_NL, DLM_LKF_CONVERT);
		return;
	}

	recover_size = ls->ls_recover_size;

	if (lvb_gen <= start_gen) {
		/*
		 * Clear lvb bits for jids we've successfully recovered.
		 * Because all nodes attempt to recover failed journals,
		 * a journal can be recovered multiple times successfully
		 * in succession.  Only the first will really do recovery,
		 * the others find it clean, but still report a successful
		 * recovery.  So, another node may have already recovered
		 * the jid and cleared the lvb bit for it.
		 */
		for (i = 0; i < recover_size; i++) {
			if (ls->ls_recover_result[i] != LM_RD_SUCCESS)
				continue;

			ls->ls_recover_result[i] = 0;

			if (!test_bit_le(i, ls->ls_lvb_bits + JID_BITMAP_OFFSET))
				continue;

			__clear_bit_le(i, ls->ls_lvb_bits + JID_BITMAP_OFFSET);
			write_lvb = 1;
		}
	}

	if (lvb_gen == start_gen) {
		/*
		 * Failed slots before start_gen are already set in lvb.
		 */
		for (i = 0; i < recover_size; i++) {
			if (!ls->ls_recover_submit[i])
				continue;
			if (ls->ls_recover_submit[i] < lvb_gen)
				ls->ls_recover_submit[i] = 0;
		}
	} else if (lvb_gen < start_gen) {
		/*
		 * Failed slots before start_gen are not yet set in lvb.
		 */
		for (i = 0; i < recover_size; i++) {
			if (!ls->ls_recover_submit[i])

Annotation

Implementation Notes