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author | Dave Airlie <airlied@redhat.com> | 2013-11-08 06:34:39 (GMT) |
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committer | Dave Airlie <airlied@redhat.com> | 2013-11-08 06:34:39 (GMT) |
commit | 91915260ea5ed9d9b19bfb75d53c989c8ada2ab0 (patch) | |
tree | f7eb16ced65f39ebd0bb32e3b4e5e0f365755536 /drivers/scsi/sg.c | |
parent | 21136946c495b0e1e0f7e25a8de6f170efbdeadf (diff) | |
parent | 07bf139b906013ecef0c5e0441564d1ae10e974a (diff) | |
download | linux-91915260ea5ed9d9b19bfb75d53c989c8ada2ab0.tar.xz |
Merge tag 'drm-intel-fixes-2013-11-07' of git://people.freedesktop.org/~danvet/drm-intel into drm-next
Bit a bit -fixes pull request in the merge window than usual dua to two
feauture-y things:
- Display CRCs are now enabled on all platforms, including the odd DP case
on gm45/vlv. Since this is a testing-only feature it should ever hurt,
but I figured it'll help with regression-testing -fixes. So I left it
in and didn't postpone it to 3.14.
- Display power well refactoring from Imre. Would have caused major pain
conflict with the bdw stage 1 patches if I'd postpone this to -next.
It's only an relatively small interface rework, so shouldn't cause pain.
It's also been in my tree since almost 3 weeks already.
That accounts for about two thirds of the pull, otherwise just bugfixes:
- vlv backlight fix from Jesse/Jani
- vlv vblank timestamp fix from Jesse
- improved edp detection through vbt from Ville (fixes a vlv issue)
- eDP vdd fix from Paulo
- fixes for dvo lvds on i830M
- a few smaller things all over
Note: This contains a backmerge of v3.12. Since the -internal branch
always applied on top of -nightly I need that unified base to merge bdw
patches. So you'll get a conflict with radeon connector props when pulling
this (and nouveau/master will also conflict a bit when Ben doesn't
rebase). The backmerge itself only had conflicts in drm/i915.
There's also a tiny conflict between Jani's backlight fix and your sysfs
lifetime fix in drm-next.
* tag 'drm-intel-fixes-2013-11-07' of git://people.freedesktop.org/~danvet/drm-intel: (940 commits)
drm/i915/vlv: use per-pipe backlight controls v2
drm/i915: make backlight functions take a connector
drm/i915: move opregion asle request handling to a work queue
drm/i915/vlv: use PIPE_START_VBLANK interrupts on VLV
drm/i915: Make intel_dp_is_edp() less specific
drm/i915: Give names to the VBT child device type bits
drm/i915/vlv: enable HDA display audio for Valleyview2
drm/i915/dvo: call ->mode_set callback only when the port is running
drm/i915: avoid unclaimed registers when capturing the error state
drm/i915: Enable DP port CRC for the "auto" source on g4x/vlv
drm/i915: scramble reset support for DP port CRC on vlv
drm/i915: scramble reset support for DP port CRC on g4x
drm/i916: add "auto" pipe CRC source
...
Conflicts:
MAINTAINERS
drivers/gpu/drm/i915/intel_panel.c
drivers/gpu/drm/nouveau/core/subdev/mc/base.c
drivers/gpu/drm/radeon/atombios_encoders.c
drivers/gpu/drm/radeon/radeon_connectors.c
Diffstat (limited to 'drivers/scsi/sg.c')
-rw-r--r-- | drivers/scsi/sg.c | 176 |
1 files changed, 95 insertions, 81 deletions
diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c index 5cbc4bb..df5e961 100644 --- a/drivers/scsi/sg.c +++ b/drivers/scsi/sg.c @@ -105,8 +105,11 @@ static int scatter_elem_sz_prev = SG_SCATTER_SZ; static int sg_add(struct device *, struct class_interface *); static void sg_remove(struct device *, struct class_interface *); +static DEFINE_SPINLOCK(sg_open_exclusive_lock); + static DEFINE_IDR(sg_index_idr); -static DEFINE_RWLOCK(sg_index_lock); +static DEFINE_RWLOCK(sg_index_lock); /* Also used to lock + file descriptor list for device */ static struct class_interface sg_interface = { .add_dev = sg_add, @@ -143,7 +146,8 @@ typedef struct sg_request { /* SG_MAX_QUEUE requests outstanding per file */ } Sg_request; typedef struct sg_fd { /* holds the state of a file descriptor */ - struct list_head sfd_siblings; /* protected by sfd_lock of device */ + /* sfd_siblings is protected by sg_index_lock */ + struct list_head sfd_siblings; 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 */ @@ -166,12 +170,13 @@ typedef struct sg_fd { /* holds the state of a file descriptor */ typedef struct sg_device { /* holds the state of each scsi generic device */ struct scsi_device *device; + wait_queue_head_t o_excl_wait; /* queue open() when O_EXCL in use */ int sg_tablesize; /* adapter's max scatter-gather table size */ u32 index; /* device index number */ - spinlock_t sfd_lock; /* protect file descriptor list for device */ + /* sfds is protected by sg_index_lock */ struct list_head sfds; - struct rw_semaphore o_sem; /* exclude open should hold this rwsem */ volatile char detached; /* 0->attached, 1->detached pending removal */ + /* exclude protected by sg_open_exclusive_lock */ char exclude; /* opened for exclusive access */ char sgdebug; /* 0->off, 1->sense, 9->dump dev, 10-> all devs */ struct gendisk *disk; @@ -220,14 +225,35 @@ static int sg_allow_access(struct file *filp, unsigned char *cmd) return blk_verify_command(cmd, filp->f_mode & FMODE_WRITE); } +static int get_exclude(Sg_device *sdp) +{ + unsigned long flags; + int ret; + + spin_lock_irqsave(&sg_open_exclusive_lock, flags); + ret = sdp->exclude; + spin_unlock_irqrestore(&sg_open_exclusive_lock, flags); + return ret; +} + +static int set_exclude(Sg_device *sdp, char val) +{ + unsigned long flags; + + spin_lock_irqsave(&sg_open_exclusive_lock, flags); + sdp->exclude = val; + spin_unlock_irqrestore(&sg_open_exclusive_lock, flags); + return val; +} + static int sfds_list_empty(Sg_device *sdp) { unsigned long flags; int ret; - spin_lock_irqsave(&sdp->sfd_lock, flags); + read_lock_irqsave(&sg_index_lock, flags); ret = list_empty(&sdp->sfds); - spin_unlock_irqrestore(&sdp->sfd_lock, flags); + read_unlock_irqrestore(&sg_index_lock, flags); return ret; } @@ -239,6 +265,7 @@ sg_open(struct inode *inode, struct file *filp) struct request_queue *q; Sg_device *sdp; Sg_fd *sfp; + int res; int retval; nonseekable_open(inode, filp); @@ -267,52 +294,54 @@ sg_open(struct inode *inode, struct file *filp) goto error_out; } - if ((flags & O_EXCL) && (O_RDONLY == (flags & O_ACCMODE))) { - retval = -EPERM; /* Can't lock it with read only access */ - goto error_out; - } - if (flags & O_NONBLOCK) { - if (flags & O_EXCL) { - if (!down_write_trylock(&sdp->o_sem)) { - retval = -EBUSY; - goto error_out; - } - } else { - if (!down_read_trylock(&sdp->o_sem)) { - retval = -EBUSY; - goto error_out; - } + if (flags & O_EXCL) { + if (O_RDONLY == (flags & O_ACCMODE)) { + retval = -EPERM; /* Can't lock it with read only access */ + goto error_out; + } + if (!sfds_list_empty(sdp) && (flags & O_NONBLOCK)) { + retval = -EBUSY; + goto error_out; + } + res = wait_event_interruptible(sdp->o_excl_wait, + ((!sfds_list_empty(sdp) || get_exclude(sdp)) ? 0 : set_exclude(sdp, 1))); + if (res) { + retval = res; /* -ERESTARTSYS because signal hit process */ + goto error_out; + } + } else if (get_exclude(sdp)) { /* some other fd has an exclusive lock on dev */ + if (flags & O_NONBLOCK) { + retval = -EBUSY; + goto error_out; + } + res = wait_event_interruptible(sdp->o_excl_wait, !get_exclude(sdp)); + if (res) { + retval = res; /* -ERESTARTSYS because signal hit process */ + goto error_out; } - } else { - if (flags & O_EXCL) - down_write(&sdp->o_sem); - else - down_read(&sdp->o_sem); } - /* Since write lock is held, no need to check sfd_list */ - if (flags & O_EXCL) - sdp->exclude = 1; /* used by release lock */ - + if (sdp->detached) { + retval = -ENODEV; + goto error_out; + } if (sfds_list_empty(sdp)) { /* no existing opens on this device */ sdp->sgdebug = 0; q = sdp->device->request_queue; sdp->sg_tablesize = queue_max_segments(q); } - sfp = sg_add_sfp(sdp, dev); - if (!IS_ERR(sfp)) + if ((sfp = sg_add_sfp(sdp, dev))) filp->private_data = sfp; - /* retval is already provably zero at this point because of the - * check after retval = scsi_autopm_get_device(sdp->device)) - */ else { - retval = PTR_ERR(sfp); - if (flags & O_EXCL) { - sdp->exclude = 0; /* undo if error */ - up_write(&sdp->o_sem); - } else - up_read(&sdp->o_sem); + set_exclude(sdp, 0); /* undo if error */ + wake_up_interruptible(&sdp->o_excl_wait); + } + retval = -ENOMEM; + goto error_out; + } + retval = 0; error_out: + if (retval) { scsi_autopm_put_device(sdp->device); sdp_put: scsi_device_put(sdp->device); @@ -329,18 +358,13 @@ sg_release(struct inode *inode, struct file *filp) { Sg_device *sdp; Sg_fd *sfp; - int excl; if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp))) return -ENXIO; SCSI_LOG_TIMEOUT(3, printk("sg_release: %s\n", sdp->disk->disk_name)); - excl = sdp->exclude; - sdp->exclude = 0; - if (excl) - up_write(&sdp->o_sem); - else - up_read(&sdp->o_sem); + set_exclude(sdp, 0); + wake_up_interruptible(&sdp->o_excl_wait); scsi_autopm_put_device(sdp->device); kref_put(&sfp->f_ref, sg_remove_sfp); @@ -1391,9 +1415,8 @@ 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); + init_waitqueue_head(&sdp->o_excl_wait); sdp->sg_tablesize = queue_max_segments(q); sdp->index = k; kref_init(&sdp->d_ref); @@ -1526,13 +1549,11 @@ 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"); @@ -2043,7 +2064,7 @@ sg_add_sfp(Sg_device * sdp, int dev) sfp = kzalloc(sizeof(*sfp), GFP_ATOMIC | __GFP_NOWARN); if (!sfp) - return ERR_PTR(-ENOMEM); + return NULL; init_waitqueue_head(&sfp->read_wait); rwlock_init(&sfp->rq_list_lock); @@ -2057,13 +2078,9 @@ 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; - spin_lock_irqsave(&sdp->sfd_lock, iflags); - if (sdp->detached) { - spin_unlock_irqrestore(&sdp->sfd_lock, iflags); - return ERR_PTR(-ENODEV); - } + write_lock_irqsave(&sg_index_lock, iflags); list_add_tail(&sfp->sfd_siblings, &sdp->sfds); - spin_unlock_irqrestore(&sdp->sfd_lock, iflags); + write_unlock_irqrestore(&sg_index_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; @@ -2113,9 +2130,10 @@ static void sg_remove_sfp(struct kref *kref) struct sg_device *sdp = sfp->parentdp; unsigned long iflags; - spin_lock_irqsave(&sdp->sfd_lock, iflags); + write_lock_irqsave(&sg_index_lock, iflags); list_del(&sfp->sfd_siblings); - spin_unlock_irqrestore(&sdp->sfd_lock, iflags); + write_unlock_irqrestore(&sg_index_lock, iflags); + wake_up_interruptible(&sdp->o_excl_wait); INIT_WORK(&sfp->ew.work, sg_remove_sfp_usercontext); schedule_work(&sfp->ew.work); @@ -2502,7 +2520,7 @@ static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v) return 0; } -/* must be called while holding sg_index_lock and sfd_lock */ +/* must be called while holding sg_index_lock */ static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp) { int k, m, new_interface, blen, usg; @@ -2587,26 +2605,22 @@ 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) { - spin_lock(&sdp->sfd_lock); - if (!list_empty(&sdp->sfds)) { - struct scsi_device *scsidp = sdp->device; + if (sdp && !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); - } - spin_unlock(&sdp->sfd_lock); + 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, get_exclude(sdp)); + sg_proc_debug_helper(s, sdp); } read_unlock_irqrestore(&sg_index_lock, iflags); return 0; |