[PATCH] Fix misuses of bdevname()

From: Jean Delvare
Date: Fri May 09 2008 - 07:20:38 EST


bdevname() fills the buffer that it is given as a parameter, so
calling strcpy() or snprintf() on the returned value is redundant (and
probably not guaranteed to work - I don't think strcpy and snprintf
support overlapping buffers.)

Signed-off-by: Jean Delvare <khali@xxxxxxxxxxxx>
Cc: Stephen Tweedie <sct@xxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Jens Axboe <axboe@xxxxxxxxx>
---
block/blktrace.c | 2 +-
block/compat_ioctl.c | 2 +-
fs/ext4/mballoc.c | 6 ++----
fs/jbd2/journal.c | 4 ++--
4 files changed, 6 insertions(+), 8 deletions(-)

--- linux-2.6.26-rc1.orig/block/blktrace.c 2008-05-09 12:52:51.000000000 +0200
+++ linux-2.6.26-rc1/block/blktrace.c 2008-05-09 12:55:04.000000000 +0200
@@ -476,7 +476,7 @@ int blk_trace_ioctl(struct block_device

switch (cmd) {
case BLKTRACESETUP:
- strcpy(b, bdevname(bdev, b));
+ bdevname(bdev, b);
ret = blk_trace_setup(q, b, bdev->bd_dev, arg);
break;
case BLKTRACESTART:
--- linux-2.6.26-rc1.orig/block/compat_ioctl.c 2008-05-09 12:52:51.000000000 +0200
+++ linux-2.6.26-rc1/block/compat_ioctl.c 2008-05-09 12:55:04.000000000 +0200
@@ -555,7 +555,7 @@ static int compat_blk_trace_setup(struct
if (copy_from_user(&cbuts, arg, sizeof(cbuts)))
return -EFAULT;

- strcpy(b, bdevname(bdev, b));
+ bdevname(bdev, b);

buts = (struct blk_user_trace_setup) {
.act_mask = cbuts.act_mask,
--- linux-2.6.26-rc1.orig/fs/ext4/mballoc.c 2008-05-09 12:52:51.000000000 +0200
+++ linux-2.6.26-rc1/fs/ext4/mballoc.c 2008-05-09 12:55:04.000000000 +0200
@@ -2639,8 +2639,7 @@ static int ext4_mb_init_per_dev_proc(str
struct proc_dir_entry *proc;
char devname[64];

- snprintf(devname, sizeof(devname) - 1, "%s",
- bdevname(sb->s_bdev, devname));
+ bdevname(sb->s_bdev, devname);
sbi->s_mb_proc = proc_mkdir(devname, proc_root_ext4);

MB_PROC_HANDLER(EXT4_MB_STATS_NAME, stats);
@@ -2674,8 +2673,7 @@ static int ext4_mb_destroy_per_dev_proc(
if (sbi->s_mb_proc == NULL)
return -EINVAL;

- snprintf(devname, sizeof(devname) - 1, "%s",
- bdevname(sb->s_bdev, devname));
+ bdevname(sb->s_bdev, devname);
remove_proc_entry(EXT4_MB_GROUP_PREALLOC, sbi->s_mb_proc);
remove_proc_entry(EXT4_MB_STREAM_REQ, sbi->s_mb_proc);
remove_proc_entry(EXT4_MB_ORDER2_REQ, sbi->s_mb_proc);
--- linux-2.6.26-rc1.orig/fs/jbd2/journal.c 2008-05-09 12:52:51.000000000 +0200
+++ linux-2.6.26-rc1/fs/jbd2/journal.c 2008-05-09 12:55:04.000000000 +0200
@@ -901,7 +901,7 @@ static void jbd2_stats_proc_init(journal
{
char name[BDEVNAME_SIZE];

- snprintf(name, sizeof(name) - 1, "%s", bdevname(journal->j_dev, name));
+ bdevname(journal->j_dev, name);
journal->j_proc_entry = proc_mkdir(name, proc_jbd2_stats);
if (journal->j_proc_entry) {
proc_create_data("history", S_IRUGO, journal->j_proc_entry,
@@ -915,7 +915,7 @@ static void jbd2_stats_proc_exit(journal
{
char name[BDEVNAME_SIZE];

- snprintf(name, sizeof(name) - 1, "%s", bdevname(journal->j_dev, name));
+ bdevname(journal->j_dev, name);
remove_proc_entry("info", journal->j_proc_entry);
remove_proc_entry("history", journal->j_proc_entry);
remove_proc_entry(name, proc_jbd2_stats);

--
Jean Delvare
--
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