Hi Jens, On Wed, Aug 24, 2005 at 11:28:39AM +0200, Jens Axboe wrote: > Ok, updated version.
One thing I found a bit awkward was the way its putting all inodes in the root of the relayfs namespace, with the cpuid tacked on the end of the bdevname - I was a bit confused at first when a trace of sdd on my 4P box spontaneously created files for "partitions" sdd0, sdd1, sdd2, and sdd3 ;). I suppose if many more users of relayfs spring into existance, this is going to get quite ugly. Below is a patch that aligns the names to the conventions used in sysfs; so, for example, when running two traces simultaneously on /dev/sdd and /dev/sdb, instead of this: # find /relay /relay /relay/sdd3 /relay/sdd2 /relay/sdd1 /relay/sdd0 /relay/sdb3 /relay/sdb2 /relay/sdb1 /relay/sdb0 it now uses this... # find /relay /relay /relay/block /relay/block/sdd /relay/block/sdd/trace3 /relay/block/sdd/trace2 /relay/block/sdd/trace1 /relay/block/sdd/trace0 /relay/block/sdb /relay/block/sdb/trace3 /relay/block/sdb/trace2 /relay/block/sdb/trace1 /relay/block/sdb/trace0 and does the correct dynamic setup and teardown of the hierarchy as the userspace tool starts and stops tracing. I had to modify the relayfs rmdir code a bit to make this work properly, I'll send a separate patch for that shortly. > http://www.kernel.org/pub/linux/kernel/people/axboe/tools/blktrace.c > > has been updated as well, the protocol version was increased to > accomodate the trace structure changes. I have the associated userspace change for this, as well as several other fixes and tweaks for your tool - if you could slap a copyright and license notice onto that source (pretty please? :) I'll send 'em right along. cheers. -- Nathan Index: 2.6.x-xfs/drivers/block/blktrace.c =================================================================== --- 2.6.x-xfs.orig/drivers/block/blktrace.c +++ 2.6.x-xfs/drivers/block/blktrace.c @@ -40,6 +40,50 @@ void __blk_add_trace(struct blk_trace *b local_irq_restore(flags); } +static struct dentry * blk_tree_root; +static DEFINE_SPINLOCK(blk_tree_lock); + +static inline void blk_remove_root(void) +{ + if (relayfs_remove_dir(blk_tree_root) != -ENOTEMPTY) + blk_tree_root = NULL; +} + +static void blk_remove_tree(struct dentry *dir) +{ + spin_lock(&blk_tree_lock); + relayfs_remove_dir(dir); + blk_remove_root(); + spin_unlock(&blk_tree_lock); +} + +static struct dentry *blk_create_tree(const char *blk_name) +{ + struct dentry *dir; + + spin_lock(&blk_tree_lock); + if (!blk_tree_root) { + blk_tree_root = relayfs_create_dir("block", NULL); + if (!blk_tree_root) { + spin_unlock(&blk_tree_lock); + return NULL; + } + } + dir = relayfs_create_dir(blk_name, blk_tree_root); + if (!dir) + blk_remove_root(); + spin_unlock(&blk_tree_lock); + + return dir; +} + +void blk_cleanup_trace(struct blk_trace *bt) +{ + relay_close(bt->rchan); + blk_remove_tree(bt->dir); + kfree(bt); +} + int blk_stop_trace(struct block_device *bdev) { request_queue_t *q = bdev_get_queue(bdev); @@ -61,10 +105,8 @@ int blk_stop_trace(struct block_device * up(&bdev->bd_sem); - if (bt) { - relay_close(bt->rchan); - kfree(bt); - } + if (bt) + blk_cleanup_trace(bt); return ret; } @@ -74,6 +116,7 @@ int blk_start_trace(struct block_device request_queue_t *q = bdev_get_queue(bdev); struct blk_user_trace_setup buts; struct blk_trace *bt = NULL; + struct dentry *dir = NULL; char b[BDEVNAME_SIZE]; int ret; @@ -101,11 +144,16 @@ int blk_start_trace(struct block_device if (!bt) goto err; + ret = -ENOENT; + dir = blk_create_tree(bdevname(bdev, b)); + if (!dir) + goto err; + + bt->dir = dir; atomic_set(&bt->sequence, 0); - bt->rchan = relay_open(bdevname(bdev, b), NULL, buts.buf_size, - buts.buf_nr, NULL); ret = -EIO; + bt->rchan = relay_open("trace", dir, buts.buf_size, buts.buf_nr, NULL); if (!bt->rchan) goto err; @@ -122,6 +170,8 @@ int blk_start_trace(struct block_device err: up(&bdev->bd_sem); + if (dir) + blk_remove_tree(dir); if (bt) kfree(bt); return ret; Index: 2.6.x-xfs/include/linux/blktrace.h =================================================================== --- 2.6.x-xfs.orig/include/linux/blktrace.h +++ 2.6.x-xfs/include/linux/blktrace.h @@ -71,6 +71,7 @@ struct blk_io_trace { }; struct blk_trace { + struct dentry *dir; struct rchan *rchan; atomic_t sequence; u16 act_mask; @@ -89,6 +90,7 @@ struct blk_user_trace_setup { #if defined(CONFIG_BLK_DEV_IO_TRACE) extern int blk_start_trace(struct block_device *, char __user *); extern int blk_stop_trace(struct block_device *); +extern void blk_cleanup_trace(struct blk_trace *); extern void __blk_add_trace(struct blk_trace *, sector_t, int, int, u32, int, int, char *); static inline void blk_add_trace_rq(struct request_queue *q, struct request *rq, @@ -137,6 +139,7 @@ static inline void blk_add_trace_generic #else /* !CONFIG_BLK_DEV_IO_TRACE */ #define blk_start_trace(bdev, arg) (-EINVAL) #define blk_stop_trace(bdev) (-EINVAL) +#define blk_cleanup_trace(bt) do { } while (0) #define blk_add_trace_rq(q, rq, what) do { } while (0) #define blk_add_trace_bio(q, rq, what) do { } while (0) #define blk_add_trace_generic(q, rq, rw, what) do { } while (0) Index: 2.6.x-xfs/drivers/block/ll_rw_blk.c =================================================================== --- 2.6.x-xfs.orig/drivers/block/ll_rw_blk.c +++ 2.6.x-xfs/drivers/block/ll_rw_blk.c @@ -1625,8 +1625,7 @@ void blk_cleanup_queue(request_queue_t * __blk_queue_free_tags(q); if (q->blk_trace) { - relay_close(q->blk_trace->rchan); - kfree(q->blk_trace); + blk_cleanup_trace(q->blk_trace); q->blk_trace = NULL; } - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
