diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2011-01-13 10:45:01 -0800 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-01-13 10:45:01 -0800 |
commit | 275220f0fcff1adf28a717076e00f575edf05fda (patch) | |
tree | d249bccc80c64443dab211639050c4fb14332648 /drivers/cdrom/cdrom.c | |
parent | fe3c560b8a22cb28e54fe8950abef38e88d75831 (diff) | |
parent | 81c5e2ae33c4b19e53966b427e33646bf6811830 (diff) | |
download | linux-275220f0fcff1adf28a717076e00f575edf05fda.tar.bz2 |
Merge branch 'for-2.6.38/core' of git://git.kernel.dk/linux-2.6-block
* 'for-2.6.38/core' of git://git.kernel.dk/linux-2.6-block: (43 commits)
block: ensure that completion error gets properly traced
blktrace: add missing probe argument to block_bio_complete
block cfq: don't use atomic_t for cfq_group
block cfq: don't use atomic_t for cfq_queue
block: trace event block fix unassigned field
block: add internal hd part table references
block: fix accounting bug on cross partition merges
kref: add kref_test_and_get
bio-integrity: mark kintegrityd_wq highpri and CPU intensive
block: make kblockd_workqueue smarter
Revert "sd: implement sd_check_events()"
block: Clean up exit_io_context() source code.
Fix compile warnings due to missing removal of a 'ret' variable
fs/block: type signature of major_to_index(int) to major_to_index(unsigned)
block: convert !IS_ERR(p) && p to !IS_ERR_NOR_NULL(p)
cfq-iosched: don't check cfqg in choose_service_tree()
fs/splice: Pull buf->ops->confirm() from splice_from_pipe actors
cdrom: export cdrom_check_events()
sd: implement sd_check_events()
sr: implement sr_check_events()
...
Diffstat (limited to 'drivers/cdrom/cdrom.c')
-rw-r--r-- | drivers/cdrom/cdrom.c | 56 |
1 files changed, 53 insertions, 3 deletions
diff --git a/drivers/cdrom/cdrom.c b/drivers/cdrom/cdrom.c index af13c62dc473..14033a36bcd0 100644 --- a/drivers/cdrom/cdrom.c +++ b/drivers/cdrom/cdrom.c @@ -1348,7 +1348,10 @@ static int cdrom_select_disc(struct cdrom_device_info *cdi, int slot) if (!CDROM_CAN(CDC_SELECT_DISC)) return -EDRIVE_CANT_DO_THIS; - (void) cdi->ops->media_changed(cdi, slot); + if (cdi->ops->check_events) + cdi->ops->check_events(cdi, 0, slot); + else + cdi->ops->media_changed(cdi, slot); if (slot == CDSL_NONE) { /* set media changed bits, on both queues */ @@ -1392,6 +1395,42 @@ static int cdrom_select_disc(struct cdrom_device_info *cdi, int slot) return slot; } +/* + * As cdrom implements an extra ioctl consumer for media changed + * event, it needs to buffer ->check_events() output, such that event + * is not lost for both the usual VFS and ioctl paths. + * cdi->{vfs|ioctl}_events are used to buffer pending events for each + * path. + * + * XXX: Locking is non-existent. cdi->ops->check_events() can be + * called in parallel and buffering fields are accessed without any + * exclusion. The original media_changed code had the same problem. + * It might be better to simply deprecate CDROM_MEDIA_CHANGED ioctl + * and remove this cruft altogether. It doesn't have much usefulness + * at this point. + */ +static void cdrom_update_events(struct cdrom_device_info *cdi, + unsigned int clearing) +{ + unsigned int events; + + events = cdi->ops->check_events(cdi, clearing, CDSL_CURRENT); + cdi->vfs_events |= events; + cdi->ioctl_events |= events; +} + +unsigned int cdrom_check_events(struct cdrom_device_info *cdi, + unsigned int clearing) +{ + unsigned int events; + + cdrom_update_events(cdi, clearing); + events = cdi->vfs_events; + cdi->vfs_events = 0; + return events; +} +EXPORT_SYMBOL(cdrom_check_events); + /* We want to make media_changed accessible to the user through an * ioctl. The main problem now is that we must double-buffer the * low-level implementation, to assure that the VFS and the user both @@ -1403,15 +1442,26 @@ int media_changed(struct cdrom_device_info *cdi, int queue) { unsigned int mask = (1 << (queue & 1)); int ret = !!(cdi->mc_flags & mask); + bool changed; if (!CDROM_CAN(CDC_MEDIA_CHANGED)) - return ret; + return ret; + /* changed since last call? */ - if (cdi->ops->media_changed(cdi, CDSL_CURRENT)) { + if (cdi->ops->check_events) { + BUG_ON(!queue); /* shouldn't be called from VFS path */ + cdrom_update_events(cdi, DISK_EVENT_MEDIA_CHANGE); + changed = cdi->ioctl_events & DISK_EVENT_MEDIA_CHANGE; + cdi->ioctl_events = 0; + } else + changed = cdi->ops->media_changed(cdi, CDSL_CURRENT); + + if (changed) { cdi->mc_flags = 0x3; /* set bit on both queues */ ret |= 1; cdi->media_written = 0; } + cdi->mc_flags &= ~mask; /* clear bit */ return ret; } |