From c25d75a234df36446dc0d9bb3365ab8b83374d50 Mon Sep 17 00:00:00 2001 From: Nitin Gupta Date: Thu, 28 Jan 2010 21:19:59 +0530 Subject: [PATCH] Staging: ramzswap: Handle case for invalid backing swap Currently, we crash (issue BUG_ON) if backing swap disk size is zero. This can happen is user specified an extended partition or simply a bad disk as backing swap. A crash is really an unpleasant surprise to user for such trivial problems. Now, we check for this condition and simply fail device initialization if this is the case. Additional cleanups: * use static for all functions * remove extra newline between functions * memset backing_swap_name to NULL on device reset Signed-off-by: Nitin Gupta Signed-off-by: Greg Kroah-Hartman --- drivers/staging/ramzswap/ramzswap_drv.c | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-) diff --git a/drivers/staging/ramzswap/ramzswap_drv.c b/drivers/staging/ramzswap/ramzswap_drv.c index 7e0a3fab9cd4..1bca069211a8 100644 --- a/drivers/staging/ramzswap/ramzswap_drv.c +++ b/drivers/staging/ramzswap/ramzswap_drv.c @@ -220,7 +220,7 @@ out: return ret; } -void ramzswap_ioctl_get_stats(struct ramzswap *rzs, +static void ramzswap_ioctl_get_stats(struct ramzswap *rzs, struct ramzswap_ioctl_stats *s) { strncpy(s->backing_swap_name, rzs->backing_swap_name, @@ -502,6 +502,14 @@ static int setup_backing_swap(struct ramzswap *rzs) goto bad_param; } disksize = i_size_read(inode); + /* + * Can happen if user gives an extended partition as + * backing swap or simply a bad disk. + */ + if (!disksize) { + pr_err("Error reading backing swap size.\n"); + goto bad_param; + } } else if (S_ISREG(inode->i_mode)) { bdev = inode->i_sb->s_bdev; if (IS_SWAPFILE(inode)) { @@ -519,7 +527,6 @@ static int setup_backing_swap(struct ramzswap *rzs) rzs->swap_file = swap_file; rzs->backing_swap = bdev; rzs->disksize = disksize; - BUG_ON(!rzs->disksize); return 0; @@ -537,7 +544,7 @@ out: * Map logical page number 'pagenum' to physical page number * on backing swap device. For block device, this is a nop. */ -u32 map_backing_swap_page(struct ramzswap *rzs, u32 pagenum) +static u32 map_backing_swap_page(struct ramzswap *rzs, u32 pagenum) { u32 skip_pages, entries_per_page; size_t delta, se_offset, skipped; @@ -668,7 +675,6 @@ static int handle_uncompressed_page(struct ramzswap *rzs, struct bio *bio) return 0; } - /* * Called when request page is not present in ramzswap. * Its either in backing swap device (if present) or @@ -936,7 +942,6 @@ out: return 0; } - /* * Check if request is within bounds and page aligned. */ @@ -1064,6 +1069,7 @@ static void reset_device(struct ramzswap *rzs) bd_release(rzs->backing_swap); filp_close(rzs->swap_file, NULL); rzs->backing_swap = NULL; + memset(rzs->backing_swap_name, 0, MAX_SWAP_NAME_LEN); } /* Reset stats */ -- 2.39.2