From: Bodo Stroesser bstroesser@ts.fujitsu.com
[ Upstream commit 61fb2482216679b9e1e797440c148bb143a5040a ]
When tcmu queues a new command - no matter whether in command ring or in qfull_queue - a cmd_id from IDR udev->commands is assigned to the command.
If userspace sends a wrong command completion containing the cmd_id of a command on the qfull_queue, tcmu_handle_completions() finds the command in the IDR and calls tcmu_handle_completion() for it. This might do some nasty things because commands in qfull_queue do not have a valid dbi list.
To fix this bug, we no longer add queued commands to the idr. Instead the cmd_id is assign when a command is written to the command ring.
Due to this change I had to adapt the source code at several places where up to now an idr_for_each had been done.
[mkp: fix checkpatch warnings]
Link: https://lore.kernel.org/r/20200518164833.12775-1-bstroesser@ts.fujitsu.com Acked-by: Mike Christie mchristi@redhat.com Signed-off-by: Bodo Stroesser bstroesser@ts.fujitsu.com Signed-off-by: Martin K. Petersen martin.petersen@oracle.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/target/target_core_user.c | 154 ++++++++++++++---------------- 1 file changed, 71 insertions(+), 83 deletions(-)
diff --git a/drivers/target/target_core_user.c b/drivers/target/target_core_user.c index 9425354aef99..70c64e69a1d2 100644 --- a/drivers/target/target_core_user.c +++ b/drivers/target/target_core_user.c @@ -882,41 +882,24 @@ static inline size_t tcmu_cmd_get_cmd_size(struct tcmu_cmd *tcmu_cmd, return command_size; }
-static int tcmu_setup_cmd_timer(struct tcmu_cmd *tcmu_cmd, unsigned int tmo, - struct timer_list *timer) +static void tcmu_setup_cmd_timer(struct tcmu_cmd *tcmu_cmd, unsigned int tmo, + struct timer_list *timer) { - struct tcmu_dev *udev = tcmu_cmd->tcmu_dev; - int cmd_id; - - if (tcmu_cmd->cmd_id) - goto setup_timer; - - cmd_id = idr_alloc(&udev->commands, tcmu_cmd, 1, USHRT_MAX, GFP_NOWAIT); - if (cmd_id < 0) { - pr_err("tcmu: Could not allocate cmd id.\n"); - return cmd_id; - } - tcmu_cmd->cmd_id = cmd_id; - - pr_debug("allocated cmd %u for dev %s tmo %lu\n", tcmu_cmd->cmd_id, - udev->name, tmo / MSEC_PER_SEC); - -setup_timer: if (!tmo) - return 0; + return;
tcmu_cmd->deadline = round_jiffies_up(jiffies + msecs_to_jiffies(tmo)); if (!timer_pending(timer)) mod_timer(timer, tcmu_cmd->deadline);
- return 0; + pr_debug("Timeout set up for cmd %p, dev = %s, tmo = %lu\n", tcmu_cmd, + tcmu_cmd->tcmu_dev->name, tmo / MSEC_PER_SEC); }
static int add_to_qfull_queue(struct tcmu_cmd *tcmu_cmd) { struct tcmu_dev *udev = tcmu_cmd->tcmu_dev; unsigned int tmo; - int ret;
/* * For backwards compat if qfull_time_out is not set use @@ -931,13 +914,11 @@ static int add_to_qfull_queue(struct tcmu_cmd *tcmu_cmd) else tmo = TCMU_TIME_OUT;
- ret = tcmu_setup_cmd_timer(tcmu_cmd, tmo, &udev->qfull_timer); - if (ret) - return ret; + tcmu_setup_cmd_timer(tcmu_cmd, tmo, &udev->qfull_timer);
list_add_tail(&tcmu_cmd->queue_entry, &udev->qfull_queue); - pr_debug("adding cmd %u on dev %s to ring space wait queue\n", - tcmu_cmd->cmd_id, udev->name); + pr_debug("adding cmd %p on dev %s to ring space wait queue\n", + tcmu_cmd, udev->name); return 0; }
@@ -959,7 +940,7 @@ static int queue_cmd_ring(struct tcmu_cmd *tcmu_cmd, sense_reason_t *scsi_err) struct tcmu_mailbox *mb; struct tcmu_cmd_entry *entry; struct iovec *iov; - int iov_cnt, ret; + int iov_cnt, cmd_id; uint32_t cmd_head; uint64_t cdb_off; bool copy_to_data_area; @@ -1060,14 +1041,21 @@ static int queue_cmd_ring(struct tcmu_cmd *tcmu_cmd, sense_reason_t *scsi_err) } entry->req.iov_bidi_cnt = iov_cnt;
- ret = tcmu_setup_cmd_timer(tcmu_cmd, udev->cmd_time_out, - &udev->cmd_timer); - if (ret) { - tcmu_cmd_free_data(tcmu_cmd, tcmu_cmd->dbi_cnt); + cmd_id = idr_alloc(&udev->commands, tcmu_cmd, 1, USHRT_MAX, GFP_NOWAIT); + if (cmd_id < 0) { + pr_err("tcmu: Could not allocate cmd id.\n");
+ tcmu_cmd_free_data(tcmu_cmd, tcmu_cmd->dbi_cnt); *scsi_err = TCM_OUT_OF_RESOURCES; return -1; } + tcmu_cmd->cmd_id = cmd_id; + + pr_debug("allocated cmd id %u for cmd %p dev %s\n", tcmu_cmd->cmd_id, + tcmu_cmd, udev->name); + + tcmu_setup_cmd_timer(tcmu_cmd, udev->cmd_time_out, &udev->cmd_timer); + entry->hdr.cmd_id = tcmu_cmd->cmd_id;
/* @@ -1279,50 +1267,39 @@ static unsigned int tcmu_handle_completions(struct tcmu_dev *udev) return handled; }
-static int tcmu_check_expired_cmd(int id, void *p, void *data) +static void tcmu_check_expired_ring_cmd(struct tcmu_cmd *cmd) { - struct tcmu_cmd *cmd = p; - struct tcmu_dev *udev = cmd->tcmu_dev; - u8 scsi_status; struct se_cmd *se_cmd; - bool is_running; - - if (test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags)) - return 0;
if (!time_after(jiffies, cmd->deadline)) - return 0; + return;
- is_running = test_bit(TCMU_CMD_BIT_INFLIGHT, &cmd->flags); + set_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags); + list_del_init(&cmd->queue_entry); se_cmd = cmd->se_cmd; + cmd->se_cmd = NULL;
- if (is_running) { - /* - * If cmd_time_out is disabled but qfull is set deadline - * will only reflect the qfull timeout. Ignore it. - */ - if (!udev->cmd_time_out) - return 0; + pr_debug("Timing out inflight cmd %u on dev %s.\n", + cmd->cmd_id, cmd->tcmu_dev->name);
- set_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags); - /* - * target_complete_cmd will translate this to LUN COMM FAILURE - */ - scsi_status = SAM_STAT_CHECK_CONDITION; - list_del_init(&cmd->queue_entry); - cmd->se_cmd = NULL; - } else { - list_del_init(&cmd->queue_entry); - idr_remove(&udev->commands, id); - tcmu_free_cmd(cmd); - scsi_status = SAM_STAT_TASK_SET_FULL; - } + target_complete_cmd(se_cmd, SAM_STAT_CHECK_CONDITION); +}
- pr_debug("Timing out cmd %u on dev %s that is %s.\n", - id, udev->name, is_running ? "inflight" : "queued"); +static void tcmu_check_expired_queue_cmd(struct tcmu_cmd *cmd) +{ + struct se_cmd *se_cmd;
- target_complete_cmd(se_cmd, scsi_status); - return 0; + if (!time_after(jiffies, cmd->deadline)) + return; + + list_del_init(&cmd->queue_entry); + se_cmd = cmd->se_cmd; + tcmu_free_cmd(cmd); + + pr_debug("Timing out queued cmd %p on dev %s.\n", + cmd, cmd->tcmu_dev->name); + + target_complete_cmd(se_cmd, SAM_STAT_TASK_SET_FULL); }
static void tcmu_device_timedout(struct tcmu_dev *udev) @@ -1407,16 +1384,15 @@ static struct se_device *tcmu_alloc_device(struct se_hba *hba, const char *name) return &udev->se_dev; }
-static bool run_qfull_queue(struct tcmu_dev *udev, bool fail) +static void run_qfull_queue(struct tcmu_dev *udev, bool fail) { struct tcmu_cmd *tcmu_cmd, *tmp_cmd; LIST_HEAD(cmds); - bool drained = true; sense_reason_t scsi_ret; int ret;
if (list_empty(&udev->qfull_queue)) - return true; + return;
pr_debug("running %s's cmdr queue forcefail %d\n", udev->name, fail);
@@ -1425,11 +1401,10 @@ static bool run_qfull_queue(struct tcmu_dev *udev, bool fail) list_for_each_entry_safe(tcmu_cmd, tmp_cmd, &cmds, queue_entry) { list_del_init(&tcmu_cmd->queue_entry);
- pr_debug("removing cmd %u on dev %s from queue\n", - tcmu_cmd->cmd_id, udev->name); + pr_debug("removing cmd %p on dev %s from queue\n", + tcmu_cmd, udev->name);
if (fail) { - idr_remove(&udev->commands, tcmu_cmd->cmd_id); /* * We were not able to even start the command, so * fail with busy to allow a retry in case runner @@ -1444,10 +1419,8 @@ static bool run_qfull_queue(struct tcmu_dev *udev, bool fail)
ret = queue_cmd_ring(tcmu_cmd, &scsi_ret); if (ret < 0) { - pr_debug("cmd %u on dev %s failed with %u\n", - tcmu_cmd->cmd_id, udev->name, scsi_ret); - - idr_remove(&udev->commands, tcmu_cmd->cmd_id); + pr_debug("cmd %p on dev %s failed with %u\n", + tcmu_cmd, udev->name, scsi_ret); /* * Ignore scsi_ret for now. target_complete_cmd * drops it. @@ -1462,13 +1435,11 @@ static bool run_qfull_queue(struct tcmu_dev *udev, bool fail) * the queue */ list_splice_tail(&cmds, &udev->qfull_queue); - drained = false; break; } }
tcmu_set_next_deadline(&udev->qfull_queue, &udev->qfull_timer); - return drained; }
static int tcmu_irqcontrol(struct uio_info *info, s32 irq_on) @@ -1652,6 +1623,8 @@ static void tcmu_dev_kref_release(struct kref *kref) if (tcmu_check_and_free_pending_cmd(cmd) != 0) all_expired = false; } + if (!list_empty(&udev->qfull_queue)) + all_expired = false; idr_destroy(&udev->commands); WARN_ON(!all_expired);
@@ -2037,9 +2010,6 @@ static void tcmu_reset_ring(struct tcmu_dev *udev, u8 err_level) mutex_lock(&udev->cmdr_lock);
idr_for_each_entry(&udev->commands, cmd, i) { - if (!test_bit(TCMU_CMD_BIT_INFLIGHT, &cmd->flags)) - continue; - pr_debug("removing cmd %u on dev %s from ring (is expired %d)\n", cmd->cmd_id, udev->name, test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags)); @@ -2077,6 +2047,8 @@ static void tcmu_reset_ring(struct tcmu_dev *udev, u8 err_level)
del_timer(&udev->cmd_timer);
+ run_qfull_queue(udev, false); + mutex_unlock(&udev->cmdr_lock); }
@@ -2698,6 +2670,7 @@ static void find_free_blocks(void) static void check_timedout_devices(void) { struct tcmu_dev *udev, *tmp_dev; + struct tcmu_cmd *cmd, *tmp_cmd; LIST_HEAD(devs);
spin_lock_bh(&timed_out_udevs_lock); @@ -2708,9 +2681,24 @@ static void check_timedout_devices(void) spin_unlock_bh(&timed_out_udevs_lock);
mutex_lock(&udev->cmdr_lock); - idr_for_each(&udev->commands, tcmu_check_expired_cmd, NULL);
- tcmu_set_next_deadline(&udev->inflight_queue, &udev->cmd_timer); + /* + * If cmd_time_out is disabled but qfull is set deadline + * will only reflect the qfull timeout. Ignore it. + */ + if (udev->cmd_time_out) { + list_for_each_entry_safe(cmd, tmp_cmd, + &udev->inflight_queue, + queue_entry) { + tcmu_check_expired_ring_cmd(cmd); + } + tcmu_set_next_deadline(&udev->inflight_queue, + &udev->cmd_timer); + } + list_for_each_entry_safe(cmd, tmp_cmd, &udev->qfull_queue, + queue_entry) { + tcmu_check_expired_queue_cmd(cmd); + } tcmu_set_next_deadline(&udev->qfull_queue, &udev->qfull_timer);
mutex_unlock(&udev->cmdr_lock);