Commit ae380ce0 authored by Artem Bityutskiy's avatar Artem Bityutskiy Committed by Artem Bityutskiy
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UBIFS: lessen the size of debugging info data structure 



This patch lessens the 'struct ubifs_debug_info' size by 90 bytes by
allocating less bytes for the debugfs root directory name. It introduces macros
for the name patter an length instead of hard-coding 100 bytes. It also makes
UBIFS use 'snprintf()' and teaches it to gracefully catch situations when the
name array is too short.

Additionally, this patch makes 2 unrelated changes - I just thought they do not
deserve separate commits: simplifies 'ubifs_assert()' for non-debugging case
and makes 'dbg_debugfs_init()' properly verify debugfs return code which may be
an error code or NULL, so we should you 'IS_ERR_OR_NULL()' instead of
'IS_ERR()'.

Signed-off-by: default avatarArtem Bityutskiy <Artem.Bityutskiy@nokia.com>
parent 549c999a

fs/ubifs/debug.c

+13 −5
Original line number Diff line number Diff line
@@ -2815,8 +2815,8 @@ static struct dentry *dfs_rootdir; 
int dbg_debugfs_init(void)

{

	dfs_rootdir = debugfs_create_dir("ubifs", NULL);

	if (IS_ERR(dfs_rootdir)) {

		int err = PTR_ERR(dfs_rootdir);

	if (IS_ERR_OR_NULL(dfs_rootdir)) {

		int err = dfs_rootdir ? PTR_ERR(dfs_rootdir) : -ENODEV;

		ubifs_err("cannot create \"ubifs\" debugfs directory, "

			  "error %d\n", err);

		return err;
@@ -2880,12 +2880,20 @@ static const struct file_operations dfs_fops = { 
 */

int dbg_debugfs_init_fs(struct ubifs_info *c)

{

	int err;

	int err, n;

	const char *fname;

	struct dentry *dent;

	struct ubifs_debug_info *d = c->dbg;



	sprintf(d->dfs_dir_name, "ubi%d_%d", c->vi.ubi_num, c->vi.vol_id);

	n = snprintf(d->dfs_dir_name, UBIFS_DFS_DIR_LEN + 1, UBIFS_DFS_DIR_NAME,

		     c->vi.ubi_num, c->vi.vol_id);

	if (n == UBIFS_DFS_DIR_LEN) {

		/* The array size is too small */

		fname = UBIFS_DFS_DIR_NAME;

		dent = ERR_PTR(-EINVAL);

		goto out;

	}



	fname = d->dfs_dir_name;

	dent = debugfs_create_dir(fname, dfs_rootdir);

	if (IS_ERR_OR_NULL(dent))
@@ -2916,7 +2924,7 @@ out_remove: 
	debugfs_remove_recursive(d->dfs_dir);

out:

	err = dent ? PTR_ERR(dent) : -ENODEV;

	ubifs_err("cannot create \"%s\" debugfs directory, error %d\n",

	ubifs_err("cannot create \"%s\" debugfs filr or directory, error %d\n",

		  fname, err);

	return err;

}

fs/ubifs/debug.h

+9 −2
Original line number Diff line number Diff line
@@ -33,6 +33,13 @@ typedef int (*dbg_znode_callback)(struct ubifs_info *c, 


#include <linux/random.h>



/*

 * The UBIFS debugfs directory name pattern and maximum name length (3 for "ubi"

 * + 1 for "_" and plus 2x2 for 2 UBI numbers and 1 for the trailing zero byte.

 */

#define UBIFS_DFS_DIR_NAME "ubi%d_%d"

#define UBIFS_DFS_DIR_LEN  (3 + 1 + 2*2 + 1)



/**

 * ubifs_debug_info - per-FS debugging information.

 * @old_zroot: old index root - used by 'dbg_check_old_index()'
@@ -84,7 +91,7 @@ struct ubifs_debug_info { 
	long long saved_free;

	int saved_idx_gc_cnt;



	char dfs_dir_name[100];

	char dfs_dir_name[UBIFS_DFS_DIR_LEN + 1];

	struct dentry *dfs_dir;

	struct dentry *dfs_dump_lprops;

	struct dentry *dfs_dump_budg;
@@ -313,7 +320,7 @@ void dbg_debugfs_exit_fs(struct ubifs_info *c); 


/* Use "if (0)" to make compiler check arguments even if debugging is off */

#define ubifs_assert(expr)  do {                                               \

	if (0 && (expr))                                                       \

	if (0)                                                                 \

		printk(KERN_CRIT "UBIFS assert failed in %s at %u (pid %d)\n", \

		       __func__, __LINE__, current->pid);                      \

} while (0)

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