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UBIFS: lessen the size of debugging info data structure

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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: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
This commit is contained in:
Artem Bityutskiy 2011-05-19 14:13:16 +03:00 committed by Artem Bityutskiy
parent 549c999a76
commit ae380ce047
2 changed files with 22 additions and 7 deletions
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18
fs/ubifs/debug.c
View File

@ -2815,8 +2815,8 @@ static struct dentry *dfs_rootdir;
int dbg_debugfs_init(void) int dbg_debugfs_init(void)
{ {
dfs_rootdir = debugfs_create_dir("ubifs", NULL); dfs_rootdir = debugfs_create_dir("ubifs", NULL);
if (IS_ERR(dfs_rootdir)) { if (IS_ERR_OR_NULL(dfs_rootdir)) {
int err = PTR_ERR(dfs_rootdir); int err = dfs_rootdir ? PTR_ERR(dfs_rootdir) : -ENODEV;
ubifs_err("cannot create \"ubifs\" debugfs directory, " ubifs_err("cannot create \"ubifs\" debugfs directory, "
"error %d\n", err); "error %d\n", err);
return err; return err;
@ -2880,12 +2880,20 @@ static const struct file_operations dfs_fops = {
*/ */
int dbg_debugfs_init_fs(struct ubifs_info *c) int dbg_debugfs_init_fs(struct ubifs_info *c)
{ {
int err; int err, n;
const char *fname; const char *fname;
struct dentry *dent; struct dentry *dent;
struct ubifs_debug_info *d = c->dbg; 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; fname = d->dfs_dir_name;
dent = debugfs_create_dir(fname, dfs_rootdir); dent = debugfs_create_dir(fname, dfs_rootdir);
if (IS_ERR_OR_NULL(dent)) if (IS_ERR_OR_NULL(dent))
@ -2916,7 +2924,7 @@ out_remove:
debugfs_remove_recursive(d->dfs_dir); debugfs_remove_recursive(d->dfs_dir);
out: out:
err = dent ? PTR_ERR(dent) : -ENODEV; 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); fname, err);
return err; return err;
} }

11
fs/ubifs/debug.h
View File

@ -33,6 +33,13 @@ typedef int (*dbg_znode_callback)(struct ubifs_info *c,
#include <linux/random.h> #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. * ubifs_debug_info - per-FS debugging information.
* @old_zroot: old index root - used by 'dbg_check_old_index()' * @old_zroot: old index root - used by 'dbg_check_old_index()'
@ -84,7 +91,7 @@ struct ubifs_debug_info {
long long saved_free; long long saved_free;
int saved_idx_gc_cnt; 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_dir;
struct dentry *dfs_dump_lprops; struct dentry *dfs_dump_lprops;
struct dentry *dfs_dump_budg; 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 */ /* Use "if (0)" to make compiler check arguments even if debugging is off */
#define ubifs_assert(expr) do { \ #define ubifs_assert(expr) do { \
if (0 && (expr)) \ if (0) \
printk(KERN_CRIT "UBIFS assert failed in %s at %u (pid %d)\n", \ printk(KERN_CRIT "UBIFS assert failed in %s at %u (pid %d)\n", \
__func__, __LINE__, current->pid); \ __func__, __LINE__, current->pid); \
} while (0) } while (0)