From 068281d302def5efd96d84a163ba17e85f5ea564 Mon Sep 17 00:00:00 2001 From: Kay Sievers Date: Sat, 16 Aug 2008 14:30:30 +0200 Subject: [PATCH] block: fix partial read() of /proc/{partitions,diskstats} The proc files get truncated if they do not fit into the buffer with a single read(). We need to move the seq_file index from the callback of class_find_device() to the caller of class_find_device(), to keep its value across multiple invocations of the callback. Signed-off-by: Kay Sievers Signed-off-by: Greg Kroah-Hartman --- block/genhd.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/block/genhd.c b/block/genhd.c index c13cc77291a..f34befc5484 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -293,25 +293,26 @@ void __init printk_all_partitions(void) /* iterator */ static int find_start(struct device *dev, void *data) { - loff_t k = *(loff_t *)data; + loff_t *k = data; if (dev->type != &disk_type) return 0; - if (!k--) + if (!*k) return 1; + (*k)--; return 0; } static void *part_start(struct seq_file *part, loff_t *pos) { struct device *dev; - loff_t n = *pos; + loff_t k = *pos; - if (!n) + if (!k) seq_puts(part, "major minor #blocks name\n\n"); mutex_lock(&block_class_lock); - dev = class_find_device(&block_class, NULL, (void *)pos, find_start); + dev = class_find_device(&block_class, NULL, &k, find_start); if (dev) return dev_to_disk(dev); return NULL; @@ -568,9 +569,10 @@ static struct device_type disk_type = { static void *diskstats_start(struct seq_file *part, loff_t *pos) { struct device *dev; + loff_t k = *pos; mutex_lock(&block_class_lock); - dev = class_find_device(&block_class, NULL, (void *)pos, find_start); + dev = class_find_device(&block_class, NULL, &k, find_start); if (dev) return dev_to_disk(dev); return NULL; -- 2.41.1