fix: race condition for device error propagation

src/iosched/unified.c

@@ -56,6 +56,7 @@
  */
 
 #include "libltfs/ltfs.h"
+#include "libltfs/ltfs_locking_old.h"
 #include "libltfs/tape.h"
 #include "libltfs/ltfs_fsops_raw.h"
 #include "libltfs/index_criteria.h"
@@ -252,7 +253,6 @@ void _unified_unset_write_ip(struct dentry_priv *dpr, struct unified_data *priv)
 void _unified_handle_write_error(ssize_t write_ret, struct write_request *req,
 	struct dentry_priv *dpr, struct unified_data *priv);
 int _unified_get_write_error(struct dentry_priv *dpr);
-int _unified_write_index_after_perm(int write_ret, struct unified_data *priv);
 
 /**
  * Initialize an instance of the unified scheduler.
@@ -1189,9 +1189,6 @@ void _unified_process_index_queue(struct unified_data *priv)
 				if (ret < 0) {
 					/* Index partition writer: failed to write data to the tape (%d) */
 					ltfsmsg(LTFS_WARN, 13013W, (int)ret);
-					if (IS_WRITE_PERM(-ret)) {
-						ret = tape_set_cart_volume_lock_status(priv->vol, PWE_MAM_IP);
-					}
 					_unified_handle_write_error(ret, req, dentry_priv, priv);
 					break;
 				} else {
@@ -1283,7 +1280,6 @@ void _unified_process_data_queue(enum request_state queue, struct unified_data *
 					if (ret < 0) {
 						/* Data partition writer: failed to write data to the tape (%d) */
 						ltfsmsg(LTFS_WARN, 13014W, (int)ret);
-						(void)_unified_write_index_after_perm(ret, priv);
 						_unified_handle_write_error(ret, req, dentry_priv, priv);
 						break;
 					} else {
@@ -1314,7 +1310,6 @@ void _unified_process_data_queue(enum request_state queue, struct unified_data *
 				if (ret < 0) {
 					/* Data partition writer: failed to write data to the tape (%d) */
 					ltfsmsg(LTFS_WARN, 13014W, (int)ret);
-					(void)_unified_write_index_after_perm(ret, priv);
 					break;
 				} else {
 					TAILQ_REMOVE(&local_req_list, req, list);
@@ -1961,7 +1956,6 @@ int _unified_flush_unlocked(struct dentry *d, struct unified_data *priv)
 			ret = ltfs_fsraw_write(d, req_cache, req->count, req->offset, dp_id, false, priv->vol);
 			if (ret < 0) {
 				ltfsmsg(LTFS_ERR, 13019E, (int)ret);
-				(void)_unified_write_index_after_perm(ret, priv);
 				_unified_handle_write_error(ret, req, dpr, priv);
 				break;
 			} else if (dpr->write_ip) {
@@ -2246,56 +2240,6 @@ int _unified_get_write_error(struct dentry_priv *dpr)
 	return ret;
 }
 
-int _unified_write_index_after_perm(int write_ret, struct unified_data *priv)
-{
-	int ret = 0;
-	struct tc_position err_pos;
-	uint64_t last_index_pos = UINT64_MAX;
-	unsigned long blocksize;
-
-	if (!IS_WRITE_PERM(-write_ret)) {
-		/* Nothing to do for non-medium error */
-		return ret;
-	}
-
-	ltfsmsg(LTFS_INFO, 13024I, write_ret);
-	ret = tape_set_cart_volume_lock_status(priv->vol, PWE_MAM_DP);
-	if (ret < 0)
-		ltfsmsg(LTFS_ERR, 13026E, "update MAM", ret);
-
-	blocksize = ltfs_get_blocksize(priv->vol);
-
-	ret = tape_get_first_untransfered_position(priv->vol->device, &err_pos);
-	if (ret < 0) {
-		ltfsmsg(LTFS_ERR, 13026E, "get error pos", ret);
-		return ret;
-	}
-
-	/* Check the err_pos is larger than the last index position of the partition */
-	if (err_pos.partition == ltfs_part_id2num(priv->vol->label->partid_ip, priv->vol)) {
-		last_index_pos = priv->vol->ip_coh.set_id;
-	} else {
-		last_index_pos = priv->vol->dp_coh.set_id;
-	}
-
-	if (last_index_pos > err_pos.block) {
-		ltfsmsg(LTFS_INFO, 13027I, (int)err_pos.partition,
-				(unsigned long long)err_pos.block, (unsigned long long)last_index_pos);
-		err_pos.block = last_index_pos + 1;
-	}
-
-	ltfsmsg(LTFS_INFO, 13025I, (int)err_pos.partition, (unsigned long long)err_pos.block, blocksize);
-	ret = ltfs_fsraw_cleanup_extent(priv->vol->index->root, err_pos, blocksize, priv->vol);
-	if (ret < 0) {
-		ltfsmsg(LTFS_ERR, 13026E, "extent cleanup", ret);
-		return ret;
-	}
-
-	ret = ltfs_write_index(ltfs_ip_id(priv->vol), SYNC_WRITE_PERM, priv->vol);
-
-	return ret;
-}
-
 /**
  * Enable profiler function
  * @param work_dir work directory to store profiler data

src/libltfs/iosched.c

@@ -50,8 +50,11 @@
 **
 *************************************************************************************
 */
+#include "ltfs_error.h"
 #include "ltfs_fuse.h"
+#include "ltfs_fsops_raw.h"
 #include "ltfs.h"
+#include "tape.h"
 #include "iosched.h"
 
 struct iosched_priv {
@@ -61,6 +64,53 @@ struct iosched_priv {
 	void *backend_handle;          /**< Backend private data */
 };
 
+int _iosched_write_index_after_perm(int write_ret, struct ltfs_volume *volume)
+{
+	int ret = 0;
+	struct tc_position err_pos;
+	uint64_t last_index_pos = UINT64_MAX;
+	unsigned long blocksize;
+
+	if (!IS_WRITE_PERM(-write_ret)) {
+		/* Nothing to do for non-medium error */
+		return ret;
+	}
+
+	ltfsmsg(LTFS_INFO, 13024I, write_ret);
+	blocksize = ltfs_get_blocksize(volume);
+
+	ret = tape_get_first_untransfered_position(volume->device, &err_pos);
+	if (ret < 0) {
+		ltfsmsg(LTFS_ERR, 13026E, "get error pos", ret);
+		return ret;
+	}
+
+	/* Check the err_pos is larger than the last index position of the partition */
+	if (err_pos.partition == ltfs_part_id2num(volume->label->partid_ip, volume)) {
+		last_index_pos = volume->ip_coh.set_id;
+	} else {
+		last_index_pos = volume->dp_coh.set_id;
+	}
+
+	if (last_index_pos > err_pos.block) {
+		ltfsmsg(LTFS_INFO, 13027I, (int)err_pos.partition,
+				(unsigned long long)err_pos.block, (unsigned long long)last_index_pos);
+		err_pos.block = last_index_pos + 1;
+	}
+
+	ltfsmsg(LTFS_INFO, 13025I, (int)err_pos.partition, (unsigned long long)err_pos.block, blocksize);
+	ret = ltfs_fsraw_cleanup_extent(volume->index->root, err_pos, blocksize, volume);
+	if (ret < 0) {
+		ltfsmsg(LTFS_ERR, 13026E, "extent cleanup", ret);
+		return ret;
+	}
+
+	ret = ltfs_write_index(ltfs_ip_id(volume), SYNC_WRITE_PERM, volume);
+
+	return ret;
+}
+
+
 /**
  * Initialize the I/O scheduler.
  * @param plugin The plugin to take scheduler operations from.
@@ -230,10 +280,20 @@ ssize_t iosched_write(struct dentry *d, const char *buf, size_t size, off_t offs
 	CHECK_ARG_NULL(d, -LTFS_NULL_ARG);
 
 	ret = priv->ops->write(d, buf, size, offset, isupdatetime, priv->backend_handle);
-	if (ret > 0 && (size_t) ret > size)
-		ret = size;
+	if (ret < 0) {
+		if (IS_WRITE_PERM(-ret)) {
+			mam_lockval vollock = d->matches_name_criteria ? PWE_MAM_IP : PWE_MAM_DP;
+			int sync_ret = _iosched_write_index_after_perm(ret, vol);
+			if (sync_ret < 0) {
+				tape_set_cart_volume_lock_status(vol, PWE_MAM);
+				return sync_ret;
+			}
+			tape_set_cart_volume_lock_status(vol, vollock);
+		}
+		return ret;
+	}
 
-	return ret;
+	return ret > (ssize_t)size? (ssize_t)size : ret;
 }
 
 /**

src/libltfs/ltfs.c

@@ -59,6 +59,7 @@
 
 #include "fs.h"
 #include "ltfs.h"
+#include "ltfs_error.h"
 #include "ltfs_internal.h"
 #include "libltfs/ltfslogging.h"
 #include "ltfs_copyright.h"
@@ -2431,15 +2432,14 @@ size_t ltfs_max_cache_size(struct ltfs_volume *vol)
  */
 int ltfs_write_index(char partition, char *reason, struct ltfs_volume *vol)
 {
-	int ret, ret_mam;
+	int ret;
 	struct tape_offset old_selfptr, old_backptr;
 	struct ltfs_timespec modtime_old = { .tv_sec = 0, .tv_nsec = 0 };
 	bool generation_inc = false;
 	struct tc_position physical_selfptr, current_position;
 	char *cache_path_save = NULL;
 	bool write_perm = (strcmp(reason, SYNC_WRITE_PERM) == 0);
-	bool update_vollock = false;
-	int volstat = -1, new_volstat = 0;
+	int volstat = -1;
 	char *bc_print = NULL;
 	unsigned long long diff;
 
@@ -2567,13 +2567,13 @@ int ltfs_write_index(char partition, char *reason, struct ltfs_volume *vol)
 		return -1;
 	}
 
-	/* Prior to writing the index, compare the current location of the head position to the head location 
+	/* Prior to writing the index, compare the current location of the head position to the head location
 	that is kept in the cache of ltfs (physical_selfptr). If they are different return error (-1) */
 	diff = ((unsigned long long)physical_selfptr.block - (unsigned long long)current_position.block);
 	if (diff) {
 		/* Position mismatch, diff not equal zero */
 		ltfsmsg(LTFS_INFO, 17293E, (unsigned long long)physical_selfptr.block, (unsigned long long)current_position.block);
-		return -1;
+		return -LTFS_INDEX_INVALID;
 	}
 
 	old_selfptr = vol->index->selfptr;
@@ -2594,9 +2594,6 @@ int ltfs_write_index(char partition, char *reason, struct ltfs_volume *vol)
 			vol->index->backptr = old_backptr;
 			vol->index->selfptr = old_selfptr;
 
-			if (IS_WRITE_PERM(-ret))
-				update_vollock = true;
-
 			goto out_write_perm;
 		}
 	}
@@ -2614,9 +2611,6 @@ int ltfs_write_index(char partition, char *reason, struct ltfs_volume *vol)
 		vol->index->backptr = old_backptr;
 		vol->index->selfptr = old_selfptr;
 
-		if (IS_WRITE_PERM(-ret))
-			update_vollock = true;
-
 		goto out_write_perm;
 	}
 
@@ -2631,9 +2625,6 @@ int ltfs_write_index(char partition, char *reason, struct ltfs_volume *vol)
 		vol->index->backptr = old_backptr;
 		vol->index->selfptr = old_selfptr;
 
-		if (IS_WRITE_PERM(-ret))
-			update_vollock = true;
-
 		goto out_write_perm;
 	}
 
@@ -2677,23 +2668,6 @@ int ltfs_write_index(char partition, char *reason, struct ltfs_volume *vol)
 		ltfs_mutex_unlock(&vol->device->read_only_flag_mutex);
 	}
 
-	if (update_vollock) {
-		if (volstat == PWE_MAM_DP && partition == ltfs_ip_id(vol))
-			new_volstat = PWE_MAM_BOTH;
-		else if (volstat == PWE_MAM_IP && partition == ltfs_dp_id(vol))
-			new_volstat = PWE_MAM_BOTH;
-		else if (volstat == UNLOCKED_MAM && partition == ltfs_ip_id(vol))
-			new_volstat = PWE_MAM_IP;
-		else if (volstat == UNLOCKED_MAM && partition == ltfs_dp_id(vol))
-			new_volstat = PWE_MAM_DP;
-
-		if (new_volstat) {
-			ret_mam = tape_set_cart_volume_lock_status(vol, new_volstat);
-			if (ret_mam)
-				ret = ret_mam;
-		}
-	}
-
 	return ret;
 }
 
@@ -4443,7 +4417,7 @@ static int _ltfs_write_rao_file(char *file_path_org, unsigned char *buf, size_t
 		ltfsmsg(LTFS_ERR, 10001E, __FILE__);
 		return -LTFS_NO_MEMORY;
 	}
-		
+
 	arch_open(&fd, path,
 		O_WRONLY | O_CREAT | O_TRUNC | O_BINARY,
 		SHARE_FLAG_DENYRW, PERMISSION_READWRITE);

src/libltfs/ltfs_error.h

@@ -383,6 +383,7 @@
 #define EDEV_MEDIUM_MAX              20399  /* Maximum medium error value */
 
 #define IS_MEDIUM_ERROR(e)           ((e>=EDEV_MEDIUM_MIN)&&(e<=EDEV_MEDIUM_MAX))
+#define IS_RW_PERM(e)                ((e==EDEV_RW_PERM)||(e==EDEV_READ_PERM)||(e==EDEV_WRITE_PERM))
 #define IS_READ_PERM(e)              ((e==EDEV_RW_PERM)||(e==EDEV_READ_PERM)||(e==EDEV_MEDIUM_FORMAT_CORRUPTED))
 #define IS_WRITE_PERM(e)             ((e==EDEV_RW_PERM)||(e==EDEV_WRITE_PERM)||(e==EDEV_MEDIUM_FORMAT_CORRUPTED))
 

src/libltfs/ltfs_fsops.c

@@ -56,6 +56,7 @@
 */
 
 #include "ltfs.h"
+#include "ltfs_error.h"
 #include "ltfs_internal.h"
 #include "ltfs_fsops.h"
 #include "ltfs_fsops_raw.h"
@@ -1781,10 +1782,7 @@ int ltfs_fsops_write(struct dentry *d, const char *buf, size_t count, off_t offs
 		}
 	}
 
-	if (ret < 0)
-		return ret;
-	else
-		return 0;
+	return ret < 0? ret : 0;
 }
 
 ssize_t ltfs_fsops_read(struct dentry *d, char *buf, size_t count, off_t offset,

src/tape_drivers/generic/file/filedebug_tc.c

@@ -880,9 +880,9 @@ int filedebug_write(void *device, const char *buf, size_t count, struct tc_posit
 		if ( state->write_counter > state->force_writeperm ) {
 			ltfsmsg(LTFS_ERR, 30007E, "write");
 			if (state->force_errortype)
-				return -EDEV_NO_SENSE;
+  			return -EDEV_WRITE_PERM;
 			else
-				return -EDEV_WRITE_PERM;
+  			return -EDEV_NO_SENSE;
 		} else if ( state->write_counter > (state->force_writeperm - THRESHOLD_FORCE_WRITE_NO_WRITE) ) {
 			ltfsmsg(LTFS_INFO, 30019I);
 			++state->current_position.block;
@@ -1426,7 +1426,7 @@ static inline int _sanitize_tape(struct filedebug_data *state)
 				ret = -EDEV_MEDIUM_FORMAT_ERROR;
 				break;
 		}
-	} 
+	}
 	else if (gen == DRIVE_GEN_JAG4) {
 		switch (state->conf.cart_type) {
 		case TC_MP_JB: