diff options
| -rw-r--r-- | drivers/scsi/sg.c | 62 |
1 files changed, 34 insertions, 28 deletions
diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c index 64df1ab141e..5cbc4bb1b39 100644 --- a/drivers/scsi/sg.c +++ b/drivers/scsi/sg.c @@ -106,8 +106,7 @@ static int sg_add(struct device *, struct class_interface *); static void sg_remove(struct device *, struct class_interface *); static DEFINE_IDR(sg_index_idr); -static DEFINE_RWLOCK(sg_index_lock); /* Also used to lock - file descriptor list for device */ +static DEFINE_RWLOCK(sg_index_lock); static struct class_interface sg_interface = { .add_dev = sg_add, @@ -144,8 +143,7 @@ typedef struct sg_request { /* SG_MAX_QUEUE requests outstanding per file */ } Sg_request; typedef struct sg_fd { /* holds the state of a file descriptor */ - /* sfd_siblings is protected by sg_index_lock */ - struct list_head sfd_siblings; + struct list_head sfd_siblings; /* protected by sfd_lock of device */ struct sg_device *parentdp; /* owning device */ wait_queue_head_t read_wait; /* queue read until command done */ rwlock_t rq_list_lock; /* protect access to list in req_arr */ @@ -170,7 +168,7 @@ typedef struct sg_device { /* holds the state of each scsi generic device */ struct scsi_device *device; int sg_tablesize; /* adapter's max scatter-gather table size */ u32 index; /* device index number */ - /* sfds is protected by sg_index_lock */ + spinlock_t sfd_lock; /* protect file descriptor list for device */ struct list_head sfds; struct rw_semaphore o_sem; /* exclude open should hold this rwsem */ volatile char detached; /* 0->attached, 1->detached pending removal */ @@ -227,9 +225,9 @@ static int sfds_list_empty(Sg_device *sdp) unsigned long flags; int ret; - read_lock_irqsave(&sg_index_lock, flags); + spin_lock_irqsave(&sdp->sfd_lock, flags); ret = list_empty(&sdp->sfds); - read_unlock_irqrestore(&sg_index_lock, flags); + spin_unlock_irqrestore(&sdp->sfd_lock, flags); return ret; } @@ -1393,6 +1391,7 @@ static Sg_device *sg_alloc(struct gendisk *disk, struct scsi_device *scsidp) disk->first_minor = k; sdp->disk = disk; sdp->device = scsidp; + spin_lock_init(&sdp->sfd_lock); INIT_LIST_HEAD(&sdp->sfds); init_rwsem(&sdp->o_sem); sdp->sg_tablesize = queue_max_segments(q); @@ -1527,11 +1526,13 @@ static void sg_remove(struct device *cl_dev, struct class_interface *cl_intf) /* Need a write lock to set sdp->detached. */ write_lock_irqsave(&sg_index_lock, iflags); + spin_lock(&sdp->sfd_lock); sdp->detached = 1; list_for_each_entry(sfp, &sdp->sfds, sfd_siblings) { wake_up_interruptible(&sfp->read_wait); kill_fasync(&sfp->async_qp, SIGPOLL, POLL_HUP); } + spin_unlock(&sdp->sfd_lock); write_unlock_irqrestore(&sg_index_lock, iflags); sysfs_remove_link(&scsidp->sdev_gendev.kobj, "generic"); @@ -2056,13 +2057,13 @@ sg_add_sfp(Sg_device * sdp, int dev) sfp->cmd_q = SG_DEF_COMMAND_Q; sfp->keep_orphan = SG_DEF_KEEP_ORPHAN; sfp->parentdp = sdp; - write_lock_irqsave(&sg_index_lock, iflags); + spin_lock_irqsave(&sdp->sfd_lock, iflags); if (sdp->detached) { - write_unlock_irqrestore(&sg_index_lock, iflags); + spin_unlock_irqrestore(&sdp->sfd_lock, iflags); return ERR_PTR(-ENODEV); } list_add_tail(&sfp->sfd_siblings, &sdp->sfds); - write_unlock_irqrestore(&sg_index_lock, iflags); + spin_unlock_irqrestore(&sdp->sfd_lock, iflags); SCSI_LOG_TIMEOUT(3, printk("sg_add_sfp: sfp=0x%p\n", sfp)); if (unlikely(sg_big_buff != def_reserved_size)) sg_big_buff = def_reserved_size; @@ -2109,11 +2110,12 @@ static void sg_remove_sfp_usercontext(struct work_struct *work) static void sg_remove_sfp(struct kref *kref) { struct sg_fd *sfp = container_of(kref, struct sg_fd, f_ref); + struct sg_device *sdp = sfp->parentdp; unsigned long iflags; - write_lock_irqsave(&sg_index_lock, iflags); + spin_lock_irqsave(&sdp->sfd_lock, iflags); list_del(&sfp->sfd_siblings); - write_unlock_irqrestore(&sg_index_lock, iflags); + spin_unlock_irqrestore(&sdp->sfd_lock, iflags); INIT_WORK(&sfp->ew.work, sg_remove_sfp_usercontext); schedule_work(&sfp->ew.work); @@ -2500,7 +2502,7 @@ static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v) return 0; } -/* must be called while holding sg_index_lock */ +/* must be called while holding sg_index_lock and sfd_lock */ static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp) { int k, m, new_interface, blen, usg; @@ -2585,22 +2587,26 @@ static int sg_proc_seq_show_debug(struct seq_file *s, void *v) read_lock_irqsave(&sg_index_lock, iflags); sdp = it ? sg_lookup_dev(it->index) : NULL; - if (sdp && !list_empty(&sdp->sfds)) { - struct scsi_device *scsidp = sdp->device; + if (sdp) { + spin_lock(&sdp->sfd_lock); + if (!list_empty(&sdp->sfds)) { + struct scsi_device *scsidp = sdp->device; - seq_printf(s, " >>> device=%s ", sdp->disk->disk_name); - if (sdp->detached) - seq_printf(s, "detached pending close "); - else - seq_printf - (s, "scsi%d chan=%d id=%d lun=%d em=%d", - scsidp->host->host_no, - scsidp->channel, scsidp->id, - scsidp->lun, - scsidp->host->hostt->emulated); - seq_printf(s, " sg_tablesize=%d excl=%d\n", - sdp->sg_tablesize, sdp->exclude); - sg_proc_debug_helper(s, sdp); + seq_printf(s, " >>> device=%s ", sdp->disk->disk_name); + if (sdp->detached) + seq_printf(s, "detached pending close "); + else + seq_printf + (s, "scsi%d chan=%d id=%d lun=%d em=%d", + scsidp->host->host_no, + scsidp->channel, scsidp->id, + scsidp->lun, + scsidp->host->hostt->emulated); + seq_printf(s, " sg_tablesize=%d excl=%d\n", + sdp->sg_tablesize, sdp->exclude); + sg_proc_debug_helper(s, sdp); + } + spin_unlock(&sdp->sfd_lock); } read_unlock_irqrestore(&sg_index_lock, iflags); return 0; |