Fix misuses of bdevname()

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@linux-fr.org>
Cc: Stephen Tweedie <sct@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

4 files changed, 6 insertions, 8 deletions

diff --git a/block/blktrace.c b/block/blktrace.c
index 568588cd16b2..b2cbb4e5d767 100644
--- a/block/blktrace.c
+++ b/block/blktrace.c
@@ -476,7 +476,7 @@ int blk_trace_ioctl(struct block_device *bdev, unsigned cmd, char __user *arg)
 
         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:
diff --git a/block/compat_ioctl.c b/block/compat_ioctl.c
index c70d0b6f666f..c23177e4623f 100644
--- a/block/compat_ioctl.c
+++ b/block/compat_ioctl.c
@@ -555,7 +555,7 @@ static int compat_blk_trace_setup(struct block_device *bdev, char __user *arg)
         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,
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index fbec2ef93797..b128bdc0f55c 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -2639,8 +2639,7 @@ static int ext4_mb_init_per_dev_proc(struct super_block *sb)
         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(struct super_block *sb)
         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);
diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
index 53632e3e8457..2e24567c4a79 100644
--- a/fs/jbd2/journal.c
+++ b/fs/jbd2/journal.c
@@ -901,7 +901,7 @@ static void jbd2_stats_proc_init(journal_t *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_t *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);