jbd2: clean up how the journal device name is printed

Calculate the journal device name once and stash it away in the
journal_s structure.  This avoids needing to call bdevname()
everywhere and reduces stack usage by not needing to allocate an
on-stack buffer.  In addition, we eliminate the '/' that can appear in
device names (e.g. "cciss/c0d0p9" --- see kernel bugzilla #11321) that
can cause problems when creating proc directory names, and include the
inode number to support ocfs2 which creates multiple journals with
different inode numbers.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

3 files changed, 22 insertions, 49 deletions

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index f58cc0309dc9..64e1c21eb5d2 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -1476,15 +1476,9 @@ static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
                         EXT4_INODES_PER_GROUP(sb),
                         sbi->s_mount_opt);
 
-        if (EXT4_SB(sb)->s_journal->j_inode == NULL) {
-                char b[BDEVNAME_SIZE];
-
-                printk(KERN_INFO "EXT4 FS on %s, external journal on %s\n",
-                       sb->s_id, bdevname(EXT4_SB(sb)->s_journal->j_dev, b));
-        } else {
-                printk(KERN_INFO "EXT4 FS on %s, internal journal\n",
-                       sb->s_id);
-        }
+        printk(KERN_INFO "EXT4 FS on %s, %s journal on %s\n",
+               sb->s_id, EXT4_SB(sb)->s_journal->j_inode ? "internal" :
+               "external", EXT4_SB(sb)->s_journal->j_devname);
         return res;
 }
 
diff --git a/fs/jbd2/commit.c b/fs/jbd2/commit.c
index f2ad061e95ec..b091e5378fe0 100644
--- a/fs/jbd2/commit.c
+++ b/fs/jbd2/commit.c
@@ -147,12 +147,9 @@ static int journal_submit_commit_record(journal_t *journal,
          * to remember if we sent a barrier request
          */
         if (ret == -EOPNOTSUPP && barrier_done) {
-                char b[BDEVNAME_SIZE];
-
                 printk(KERN_WARNING
-                        "JBD: barrier-based sync failed on %s - "
-                        "disabling barriers\n",
-                        bdevname(journal->j_dev, b));
+                       "JBD: barrier-based sync failed on %s - "
+                       "disabling barriers\n", journal->j_devname);
                 spin_lock(&journal->j_state_lock);
                 journal->j_flags &= ~JBD2_BARRIER;
                 spin_unlock(&journal->j_state_lock);
@@ -681,11 +678,9 @@ start_journal_io:
          */
         err = journal_finish_inode_data_buffers(journal, commit_transaction);
         if (err) {
-                char b[BDEVNAME_SIZE];
-
                 printk(KERN_WARNING
                         "JBD2: Detected IO errors while flushing file data "
-                        "on %s\n", bdevname(journal->j_fs_dev, b));
+                       "on %s\n", journal->j_devname);
                 err = 0;
         }
 
diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
index 8207a01c4edb..81186a29742e 100644
--- a/fs/jbd2/journal.c
+++ b/fs/jbd2/journal.c
@@ -597,13 +597,9 @@ int jbd2_journal_bmap(journal_t *journal, unsigned long blocknr,
                 if (ret)
                         *retp = ret;
                 else {
-                        char b[BDEVNAME_SIZE];
-
                         printk(KERN_ALERT "%s: journal block not found "
                                         "at offset %lu on %s\n",
-                                __func__,
-                                blocknr,
-                                bdevname(journal->j_dev, b));
+                               __func__, blocknr, journal->j_devname);
                         err = -EIO;
                         __journal_abort_soft(journal, err);
                 }
@@ -901,10 +897,7 @@ static struct proc_dir_entry *proc_jbd2_stats;
 
 static void jbd2_stats_proc_init(journal_t *journal)
 {
-        char name[BDEVNAME_SIZE];
-
-        bdevname(journal->j_dev, name);
-        journal->j_proc_entry = proc_mkdir(name, proc_jbd2_stats);
+        journal->j_proc_entry = proc_mkdir(journal->j_devname, proc_jbd2_stats);
         if (journal->j_proc_entry) {
                 proc_create_data("history", S_IRUGO, journal->j_proc_entry,
                                  &jbd2_seq_history_fops, journal);
@@ -915,12 +908,9 @@ static void jbd2_stats_proc_init(journal_t *journal)
 
 static void jbd2_stats_proc_exit(journal_t *journal)
 {
-        char name[BDEVNAME_SIZE];
-
-        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);
+        remove_proc_entry(journal->j_devname, proc_jbd2_stats);
 }
 
 static void journal_init_stats(journal_t *journal)
@@ -1018,6 +1008,7 @@ journal_t * jbd2_journal_init_dev(struct block_device *bdev,
 {
         journal_t *journal = journal_init_common();
         struct buffer_head *bh;
+        char *p;
         int n;
 
         if (!journal)
@@ -1039,6 +1030,10 @@ journal_t * jbd2_journal_init_dev(struct block_device *bdev,
         journal->j_fs_dev = fs_dev;
         journal->j_blk_offset = start;
         journal->j_maxlen = len;
+        bdevname(journal->j_dev, journal->j_devname);
+        p = journal->j_devname;
+        while ((p = strchr(p, '/')))
+                *p = '!';
         jbd2_stats_proc_init(journal);
 
         bh = __getblk(journal->j_dev, start, journal->j_blocksize);
@@ -1061,6 +1056,7 @@ journal_t * jbd2_journal_init_inode (struct inode *inode)
 {
         struct buffer_head *bh;
         journal_t *journal = journal_init_common();
+        char *p;
         int err;
         int n;
         unsigned long long blocknr;
@@ -1070,6 +1066,12 @@ journal_t * jbd2_journal_init_inode (struct inode *inode)
 
         journal->j_dev = journal->j_fs_dev = inode->i_sb->s_bdev;
         journal->j_inode = inode;
+        bdevname(journal->j_dev, journal->j_devname);
+        p = journal->j_devname;
+        while ((p = strchr(p, '/')))
+                *p = '!';
+        p = journal->j_devname + strlen(journal->j_devname);
+        sprintf(p, ":%lu", journal->j_inode->i_ino);
         jbd_debug(1,
                   "journal %p: inode %s/%ld, size %Ld, bits %d, blksize %ld\n",
                   journal, inode->i_sb->s_id, inode->i_ino,
@@ -1761,23 +1763,6 @@ int jbd2_journal_wipe(journal_t *journal, int write)
 }
 
 /*
- * journal_dev_name: format a character string to describe on what
- * device this journal is present.
- */
-
-static const char *journal_dev_name(journal_t *journal, char *buffer)
-{
-        struct block_device *bdev;
-
-        if (journal->j_inode)
-                bdev = journal->j_inode->i_sb->s_bdev;
-        else
-                bdev = journal->j_dev;
-
-        return bdevname(bdev, buffer);
-}
-
-/*
  * Journal abort has very specific semantics, which we describe
  * for journal abort.
  *
@@ -1793,13 +1778,12 @@ static const char *journal_dev_name(journal_t *journal, char *buffer)
 void __jbd2_journal_abort_hard(journal_t *journal)
 {
         transaction_t *transaction;
-        char b[BDEVNAME_SIZE];
 
         if (journal->j_flags & JBD2_ABORT)
                 return;
 
         printk(KERN_ERR "Aborting journal on device %s.\n",
-                journal_dev_name(journal, b));
+               journal->j_devname);
 
         spin_lock(&journal->j_state_lock);
         journal->j_flags |= JBD2_ABORT;