From 262bf54144ebcb78cd0d057d2705dc5fb7bba7ac Mon Sep 17 00:00:00 2001 From: "Ed L. Cashin" Date: Fri, 8 Feb 2008 04:20:03 -0800 Subject: aoe: user can ask driver to forget previously detected devices When an AoE device is detected, the kernel is informed, and a new block device is created. If the device is unused, the block device corresponding to remote device that is no longer available may be removed from the system by telling the aoe driver to "flush" its list of devices. Without this patch, software like GPFS and LVM may attempt to read from AoE devices that were discovered earlier but are no longer present, blocking until the I/O attempt times out. Signed-off-by: Ed L. Cashin Cc: Greg KH Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Documentation/aoe/mkdevs.sh | 2 ++ Documentation/aoe/udev.txt | 1 + drivers/block/aoe/aoe.h | 1 + drivers/block/aoe/aoechr.c | 5 +++ drivers/block/aoe/aoedev.c | 87 +++++++++++++++++++++++++++++++++++---------- 5 files changed, 77 insertions(+), 19 deletions(-) diff --git a/Documentation/aoe/mkdevs.sh b/Documentation/aoe/mkdevs.sh index 97374aacacb..44c0ab70243 100644 --- a/Documentation/aoe/mkdevs.sh +++ b/Documentation/aoe/mkdevs.sh @@ -29,6 +29,8 @@ rm -f $dir/interfaces mknod -m 0200 $dir/interfaces c $MAJOR 4 rm -f $dir/revalidate mknod -m 0200 $dir/revalidate c $MAJOR 5 +rm -f $dir/flush +mknod -m 0200 $dir/flush c $MAJOR 6 export n_partitions mkshelf=`echo $0 | sed 's!mkdevs!mkshelf!'` diff --git a/Documentation/aoe/udev.txt b/Documentation/aoe/udev.txt index 17e76c4f918..8686e789542 100644 --- a/Documentation/aoe/udev.txt +++ b/Documentation/aoe/udev.txt @@ -20,6 +20,7 @@ SUBSYSTEM=="aoe", KERNEL=="discover", NAME="etherd/%k", GROUP="disk", MODE="0220 SUBSYSTEM=="aoe", KERNEL=="err", NAME="etherd/%k", GROUP="disk", MODE="0440" SUBSYSTEM=="aoe", KERNEL=="interfaces", NAME="etherd/%k", GROUP="disk", MODE="0220" SUBSYSTEM=="aoe", KERNEL=="revalidate", NAME="etherd/%k", GROUP="disk", MODE="0220" +SUBSYSTEM=="aoe", KERNEL=="flush", NAME="etherd/%k", GROUP="disk", MODE="0220" # aoe block devices KERNEL=="etherd*", NAME="%k", GROUP="disk" diff --git a/drivers/block/aoe/aoe.h b/drivers/block/aoe/aoe.h index aecaac3f2e5..2248ab22657 100644 --- a/drivers/block/aoe/aoe.h +++ b/drivers/block/aoe/aoe.h @@ -191,6 +191,7 @@ struct aoedev *aoedev_by_aoeaddr(int maj, int min); struct aoedev *aoedev_by_sysminor_m(ulong sysminor); void aoedev_downdev(struct aoedev *d); int aoedev_isbusy(struct aoedev *d); +int aoedev_flush(const char __user *str, size_t size); int aoenet_init(void); void aoenet_exit(void); diff --git a/drivers/block/aoe/aoechr.c b/drivers/block/aoe/aoechr.c index f1124664c5c..1bc85aa2271 100644 --- a/drivers/block/aoe/aoechr.c +++ b/drivers/block/aoe/aoechr.c @@ -15,6 +15,7 @@ enum { MINOR_DISCOVER, MINOR_INTERFACES, MINOR_REVALIDATE, + MINOR_FLUSH, MSGSZ = 2048, NMSG = 100, /* message backlog to retain */ }; @@ -43,6 +44,7 @@ static struct aoe_chardev chardevs[] = { { MINOR_DISCOVER, "discover" }, { MINOR_INTERFACES, "interfaces" }, { MINOR_REVALIDATE, "revalidate" }, + { MINOR_FLUSH, "flush" }, }; static int @@ -158,6 +160,9 @@ aoechr_write(struct file *filp, const char __user *buf, size_t cnt, loff_t *offp break; case MINOR_REVALIDATE: ret = revalidate(buf, cnt); + break; + case MINOR_FLUSH: + ret = aoedev_flush(buf, cnt); } if (ret == 0) ret = cnt; diff --git a/drivers/block/aoe/aoedev.c b/drivers/block/aoe/aoedev.c index a4d625aefea..e26f6f4a28a 100644 --- a/drivers/block/aoe/aoedev.c +++ b/drivers/block/aoe/aoedev.c @@ -9,6 +9,10 @@ #include #include "aoe.h" +static void dummy_timer(ulong); +static void aoedev_freedev(struct aoedev *); +static void freetgt(struct aoetgt *t); + static struct aoedev *devlist; static spinlock_t devlist_lock; @@ -108,6 +112,70 @@ aoedev_downdev(struct aoedev *d) d->flags &= ~DEVFL_UP; } +static void +aoedev_freedev(struct aoedev *d) +{ + struct aoetgt **t, **e; + + if (d->gd) { + aoedisk_rm_sysfs(d); + del_gendisk(d->gd); + put_disk(d->gd); + } + t = d->targets; + e = t + NTARGETS; + for (; t < e && *t; t++) + freetgt(*t); + if (d->bufpool) + mempool_destroy(d->bufpool); + kfree(d); +} + +int +aoedev_flush(const char __user *str, size_t cnt) +{ + ulong flags; + struct aoedev *d, **dd; + struct aoedev *rmd = NULL; + char buf[16]; + int all = 0; + + if (cnt >= 3) { + if (cnt > sizeof buf) + cnt = sizeof buf; + if (copy_from_user(buf, str, cnt)) + return -EFAULT; + all = !strncmp(buf, "all", 3); + } + + flush_scheduled_work(); + spin_lock_irqsave(&devlist_lock, flags); + dd = &devlist; + while ((d = *dd)) { + spin_lock(&d->lock); + if ((!all && (d->flags & DEVFL_UP)) + || (d->flags & (DEVFL_GDALLOC|DEVFL_NEWSIZE)) + || d->nopen) { + spin_unlock(&d->lock); + dd = &d->next; + continue; + } + *dd = d->next; + aoedev_downdev(d); + d->flags |= DEVFL_TKILL; + spin_unlock(&d->lock); + d->next = rmd; + rmd = d; + } + spin_unlock_irqrestore(&devlist_lock, flags); + while ((d = rmd)) { + rmd = d->next; + del_timer_sync(&d->timer); + aoedev_freedev(d); /* must be able to sleep */ + } + return 0; +} + /* find it or malloc it */ struct aoedev * aoedev_by_sysminor_m(ulong sysminor) @@ -161,25 +229,6 @@ freetgt(struct aoetgt *t) kfree(t); } -static void -aoedev_freedev(struct aoedev *d) -{ - struct aoetgt **t, **e; - - if (d->gd) { - aoedisk_rm_sysfs(d); - del_gendisk(d->gd); - put_disk(d->gd); - } - t = d->targets; - e = t + NTARGETS; - for (; t < e && *t; t++) - freetgt(*t); - if (d->bufpool) - mempool_destroy(d->bufpool); - kfree(d); -} - void aoedev_exit(void) { -- cgit v1.2.3