[PATCH 19/42] jbd2: clean up how the journal device name is printed

From: Theodore Ts'o
Date: Thu Oct 09 2008 - 00:19:31 EST


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@xxxxxxx>
---
fs/ext4/super.c | 12 +++---------
fs/jbd2/commit.c | 11 +++--------
fs/jbd2/journal.c | 48 ++++++++++++++++--------------------------------
include/linux/jbd2.h | 3 ++-
4 files changed, 24 insertions(+), 50 deletions(-)

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index f58cc03..64e1c21 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 f2ad061..b091e53 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 8207a01..81186a2 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;
diff --git a/include/linux/jbd2.h b/include/linux/jbd2.h
index 3dd2090..66c3499 100644
--- a/include/linux/jbd2.h
+++ b/include/linux/jbd2.h
@@ -850,7 +850,8 @@ struct journal_s
*/
struct block_device *j_dev;
int j_blocksize;
- unsigned long long j_blk_offset;
+ unsigned long long j_blk_offset;
+ char j_devname[BDEVNAME_SIZE+24];

/*
* Device which holds the client fs. For internal journal this will be
--
1.5.6.1.205.ge2c7.dirty

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/