ext4: mballoc: make mb_debug() implementation to use pr_debug()

mb_debug() msg had only 1 control level for all type of msgs.
And if we enable mballoc_debug then all of those msgs would be enabled.
Instead of adding multiple debug levels for mb_debug() msgs, use
pr_debug() with which we could have finer control to print msgs at all
of different levels (i.e. at file, func, line no.).

Also add process name/pid, superblk id, and other info in mb_debug()
msg. This also kills the mballoc_debug module parameter, since it is
not needed any more.

Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com>
Link: https://lore.kernel.org/r/f0c660cbde9e2edbe95c67942ca9ad80dd2231eb.1589086800.git.riteshh@linux.ibm.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

diff --git a/fs/ext4/Kconfig b/fs/ext4/Kconfig
index 2a592e3..02376dd 100644 (file)
--- a/fs/ext4/Kconfig
+++ b/fs/ext4/Kconfig
@@ -99,8 +99,7 @@ config EXT4_DEBUG
          Enables run-time debugging support for the ext4 filesystem.
 
          If you select Y here, then you will be able to turn on debugging
-         with a command such as:
-               echo 1 > /sys/module/ext4/parameters/mballoc_debug
+         using dynamic debug control for mb_debug() msgs.
 
 config EXT4_KUNIT_TESTS
        tristate "KUnit tests for ext4"

diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index c713d06..33a6942 100644 (file)
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -18,13 +18,6 @@
 #include <linux/backing-dev.h>
 #include <trace/events/ext4.h>
 
-#ifdef CONFIG_EXT4_DEBUG
-ushort ext4_mballoc_debug __read_mostly;
-
-module_param_named(mballoc_debug, ext4_mballoc_debug, ushort, 0644);
-MODULE_PARM_DESC(mballoc_debug, "Debugging level for ext4's mballoc");
-#endif
-
 /*
  * MUSTDO:
  *   - test ext4_ext_search_left() and ext4_ext_search_right()
@@ -858,14 +851,14 @@ static int ext4_mb_init_cache(struct page *page, char *incore, gfp_t gfp)
        char *bitmap;
        struct ext4_group_info *grinfo;
 
-       mb_debug(1, "init page %lu\n", page->index);
-
        inode = page->mapping->host;
        sb = inode->i_sb;
        ngroups = ext4_get_groups_count(sb);
        blocksize = i_blocksize(inode);
        blocks_per_page = PAGE_SIZE / blocksize;
 
+       mb_debug(sb, "init page %lu\n", page->index);
+
        groups_per_page = blocks_per_page >> 1;
        if (groups_per_page == 0)
                groups_per_page = 1;
@@ -905,7 +898,7 @@ static int ext4_mb_init_cache(struct page *page, char *incore, gfp_t gfp)
                        bh[i] = NULL;
                        goto out;
                }
-               mb_debug(1, "read bitmap for group %u\n", group);
+               mb_debug(sb, "read bitmap for group %u\n", group);
        }
 
        /* wait for I/O completion */
@@ -950,7 +943,7 @@ static int ext4_mb_init_cache(struct page *page, char *incore, gfp_t gfp)
                if ((first_block + i) & 1) {
                        /* this is block of buddy */
                        BUG_ON(incore == NULL);
-                       mb_debug(1, "put buddy for group %u in page %lu/%x\n",
+                       mb_debug(sb, "put buddy for group %u in page %lu/%x\n",
                                group, page->index, i * blocksize);
                        trace_ext4_mb_buddy_bitmap_load(sb, group);
                        grinfo = ext4_get_group_info(sb, group);
@@ -970,7 +963,7 @@ static int ext4_mb_init_cache(struct page *page, char *incore, gfp_t gfp)
                } else {
                        /* this is block of bitmap */
                        BUG_ON(incore != NULL);
-                       mb_debug(1, "put bitmap for group %u in page %lu/%x\n",
+                       mb_debug(sb, "put bitmap for group %u in page %lu/%x\n",
                                group, page->index, i * blocksize);
                        trace_ext4_mb_bitmap_load(sb, group);
 
@@ -1076,7 +1069,7 @@ int ext4_mb_init_group(struct super_block *sb, ext4_group_t group, gfp_t gfp)
        int ret = 0;
 
        might_sleep();
-       mb_debug(1, "init group %u\n", group);
+       mb_debug(sb, "init group %u\n", group);
        this_grp = ext4_get_group_info(sb, group);
        /*
         * This ensures that we don't reinit the buddy cache
@@ -1148,7 +1141,7 @@ ext4_mb_load_buddy_gfp(struct super_block *sb, ext4_group_t group,
        struct inode *inode = sbi->s_buddy_cache;
 
        might_sleep();
-       mb_debug(1, "load group %u\n", group);
+       mb_debug(sb, "load group %u\n", group);
 
        blocks_per_page = PAGE_SIZE / sb->s_blocksize;
        grp = ext4_get_group_info(sb, group);
@@ -2299,7 +2292,7 @@ out:
        if (!err && ac->ac_status != AC_STATUS_FOUND && first_err)
                err = first_err;
 
-       mb_debug(1, "Best len %d, origin len %d, ac_status %u, ac_flags 0x%x, cr %d ret %d\n",
+       mb_debug(sb, "Best len %d, origin len %d, ac_status %u, ac_flags 0x%x, cr %d ret %d\n",
                 ac->ac_b_ex.fe_len, ac->ac_o_ex.fe_len, ac->ac_status,
                 ac->ac_flags, cr, err);
        return err;
@@ -2731,7 +2724,7 @@ out:
 }
 
 /* need to called with the ext4 group lock held */
-static void ext4_mb_cleanup_pa(struct ext4_group_info *grp)
+static int ext4_mb_cleanup_pa(struct ext4_group_info *grp)
 {
        struct ext4_prealloc_space *pa;
        struct list_head *cur, *tmp;
@@ -2743,9 +2736,7 @@ static void ext4_mb_cleanup_pa(struct ext4_group_info *grp)
                count++;
                kmem_cache_free(ext4_pspace_cachep, pa);
        }
-       if (count)
-               mb_debug(1, "mballoc: %u PAs left\n", count);
-
+       return count;
 }
 
 int ext4_mb_release(struct super_block *sb)
@@ -2756,6 +2747,7 @@ int ext4_mb_release(struct super_block *sb)
        struct ext4_group_info *grinfo, ***group_info;
        struct ext4_sb_info *sbi = EXT4_SB(sb);
        struct kmem_cache *cachep = get_groupinfo_cache(sb->s_blocksize_bits);
+       int count;
 
        if (sbi->s_group_info) {
                for (i = 0; i < ngroups; i++) {
@@ -2763,7 +2755,10 @@ int ext4_mb_release(struct super_block *sb)
                        grinfo = ext4_get_group_info(sb, i);
                        mb_group_bb_bitmap_free(grinfo);
                        ext4_lock_group(sb, i);
-                       ext4_mb_cleanup_pa(grinfo);
+                       count = ext4_mb_cleanup_pa(grinfo);
+                       if (count)
+                               mb_debug(sb, "mballoc: %d PAs left\n",
+                                        count);
                        ext4_unlock_group(sb, i);
                        kmem_cache_free(cachep, grinfo);
                }
@@ -2836,7 +2831,7 @@ static void ext4_free_data_in_buddy(struct super_block *sb,
        struct ext4_group_info *db;
        int err, count = 0, count2 = 0;
 
-       mb_debug(1, "gonna free %u blocks in group %u (0x%p):",
+       mb_debug(sb, "gonna free %u blocks in group %u (0x%p):",
                 entry->efd_count, entry->efd_group, entry);
 
        err = ext4_mb_load_buddy(sb, entry->efd_group, &e4b);
@@ -2876,7 +2871,8 @@ static void ext4_free_data_in_buddy(struct super_block *sb,
        kmem_cache_free(ext4_free_data_cachep, entry);
        ext4_mb_unload_buddy(&e4b);
 
-       mb_debug(1, "freed %u blocks in %u structures\n", count, count2);
+       mb_debug(sb, "freed %d blocks in %d structures\n", count,
+                count2);
 }
 
 /*
@@ -3107,8 +3103,7 @@ static void ext4_mb_normalize_group_request(struct ext4_allocation_context *ac)
 
        BUG_ON(lg == NULL);
        ac->ac_g_ex.fe_len = EXT4_SB(sb)->s_mb_group_prealloc;
-       mb_debug(1, "#%u: goal %u blocks for locality group\n",
-               current->pid, ac->ac_g_ex.fe_len);
+       mb_debug(sb, "goal %u blocks for locality group\n", ac->ac_g_ex.fe_len);
 }
 
 /*
@@ -3306,8 +3301,8 @@ ext4_mb_normalize_request(struct ext4_allocation_context *ac,
                ac->ac_flags |= EXT4_MB_HINT_TRY_GOAL;
        }
 
-       mb_debug(1, "goal: %lld(was %lld) blocks at %u\n", size, orig_size,
-                start);
+       mb_debug(ac->ac_sb, "goal: %lld(was %lld) blocks at %u\n", size,
+                orig_size, start);
 }
 
 static void ext4_mb_collect_stats(struct ext4_allocation_context *ac)
@@ -3396,7 +3391,7 @@ static void ext4_mb_use_inode_pa(struct ext4_allocation_context *ac,
        BUG_ON(pa->pa_free < len);
        pa->pa_free -= len;
 
-       mb_debug(1, "use %llu/%d from inode pa %p\n", start, len, pa);
+       mb_debug(ac->ac_sb, "use %llu/%d from inode pa %p\n", start, len, pa);
 }
 
 /*
@@ -3420,7 +3415,8 @@ static void ext4_mb_use_group_pa(struct ext4_allocation_context *ac,
         * in on-disk bitmap -- see ext4_mb_release_context()
         * Other CPUs are prevented from allocating from this pa by lg_mutex
         */
-       mb_debug(1, "use %u/%u from group pa %p\n", pa->pa_lstart-len, len, pa);
+       mb_debug(ac->ac_sb, "use %u/%u from group pa %p\n",
+                pa->pa_lstart-len, len, pa);
 }
 
 /*
@@ -3603,7 +3599,7 @@ void ext4_mb_generate_from_pa(struct super_block *sb, void *bitmap,
                ext4_set_bits(bitmap, start, len);
                preallocated += len;
        }
-       mb_debug(1, "preallocated %d for group %u\n", preallocated, group);
+       mb_debug(sb, "preallocated %d for group %u\n", preallocated, group);
 }
 
 static void ext4_mb_pa_callback(struct rcu_head *head)
@@ -3746,8 +3742,8 @@ ext4_mb_new_inode_pa(struct ext4_allocation_context *ac)
        pa->pa_deleted = 0;
        pa->pa_type = MB_INODE_PA;
 
-       mb_debug(1, "new inode pa %p: %llu/%d for %u\n", pa,
-                       pa->pa_pstart, pa->pa_len, pa->pa_lstart);
+       mb_debug(sb, "new inode pa %p: %llu/%d for %u\n", pa, pa->pa_pstart,
+                pa->pa_len, pa->pa_lstart);
        trace_ext4_mb_new_inode_pa(ac, pa);
 
        ext4_mb_use_inode_pa(ac, pa);
@@ -3806,8 +3802,8 @@ ext4_mb_new_group_pa(struct ext4_allocation_context *ac)
        pa->pa_deleted = 0;
        pa->pa_type = MB_GROUP_PA;
 
-       mb_debug(1, "new group pa %p: %llu/%d for %u\n", pa,
-                       pa->pa_pstart, pa->pa_len, pa->pa_lstart);
+       mb_debug(sb, "new group pa %p: %llu/%d for %u\n", pa, pa->pa_pstart,
+                pa->pa_len, pa->pa_lstart);
        trace_ext4_mb_new_group_pa(ac, pa);
 
        ext4_mb_use_group_pa(ac, pa);
@@ -3874,7 +3870,7 @@ ext4_mb_release_inode_pa(struct ext4_buddy *e4b, struct buffer_head *bitmap_bh,
                if (bit >= end)
                        break;
                next = mb_find_next_bit(bitmap_bh->b_data, end, bit);
-               mb_debug(1, "    free preallocated %u/%u in group %u\n",
+               mb_debug(sb, "free preallocated %u/%u in group %u\n",
                         (unsigned) ext4_group_first_block_no(sb, group) + bit,
                         (unsigned) next - bit, (unsigned) group);
                free += next - bit;
@@ -3945,8 +3941,7 @@ ext4_mb_discard_group_preallocations(struct super_block *sb,
        int busy = 0;
        int free = 0;
 
-       mb_debug(1, "discard preallocation for group %u\n", group);
-
+       mb_debug(sb, "discard preallocation for group %u\n", group);
        if (list_empty(&grp->bb_prealloc_list))
                goto out_dbg;
 
@@ -4009,7 +4004,7 @@ repeat:
        /* found anything to free? */
        if (list_empty(&list)) {
                BUG_ON(free != 0);
-               mb_debug(1, "Someone else may have freed PA for this group %u\n",
+               mb_debug(sb, "Someone else may have freed PA for this group %u\n",
                         group);
                goto out;
        }
@@ -4036,7 +4031,7 @@ out:
        ext4_mb_unload_buddy(&e4b);
        put_bh(bitmap_bh);
 out_dbg:
-       mb_debug(1, "discarded (%d) blocks preallocated for group %u bb_free (%d)\n",
+       mb_debug(sb, "discarded (%d) blocks preallocated for group %u bb_free (%d)\n",
                 free, group, grp->bb_free);
        return free;
 }
@@ -4066,7 +4061,8 @@ void ext4_discard_preallocations(struct inode *inode)
                return;
        }
 
-       mb_debug(1, "discard preallocation for inode %lu\n", inode->i_ino);
+       mb_debug(sb, "discard preallocation for inode %lu\n",
+                inode->i_ino);
        trace_ext4_discard_preallocations(inode);
 
        INIT_LIST_HEAD(&list);
@@ -4159,12 +4155,11 @@ static inline void ext4_mb_show_pa(struct super_block *sb)
 {
        ext4_group_t i, ngroups;
 
-       if (!ext4_mballoc_debug ||
-           (EXT4_SB(sb)->s_mount_flags & EXT4_MF_FS_ABORTED))
+       if (EXT4_SB(sb)->s_mount_flags & EXT4_MF_FS_ABORTED)
                return;
 
        ngroups = ext4_get_groups_count(sb);
-       ext4_msg(sb, KERN_ERR, "groups: ");
+       mb_debug(sb, "groups: ");
        for (i = 0; i < ngroups; i++) {
                struct ext4_group_info *grp = ext4_get_group_info(sb, i);
                struct ext4_prealloc_space *pa;
@@ -4178,30 +4173,27 @@ static inline void ext4_mb_show_pa(struct super_block *sb)
                        ext4_get_group_no_and_offset(sb, pa->pa_pstart,
                                                     NULL, &start);
                        spin_unlock(&pa->pa_lock);
-                       printk(KERN_ERR "PA:%u:%d:%d \n", i,
-                              start, pa->pa_len);
+                       mb_debug(sb, "PA:%u:%d:%d\n", i, start,
+                                pa->pa_len);
                }
                ext4_unlock_group(sb, i);
-
-               printk(KERN_ERR "%u: %d/%d \n",
-                      i, grp->bb_free, grp->bb_fragments);
+               mb_debug(sb, "%u: %d/%d\n", i, grp->bb_free,
+                        grp->bb_fragments);
        }
-       printk(KERN_ERR "\n");
 }
 
 static void ext4_mb_show_ac(struct ext4_allocation_context *ac)
 {
        struct super_block *sb = ac->ac_sb;
 
-       if (!ext4_mballoc_debug ||
-           (EXT4_SB(sb)->s_mount_flags & EXT4_MF_FS_ABORTED))
+       if (EXT4_SB(sb)->s_mount_flags & EXT4_MF_FS_ABORTED)
                return;
 
-       ext4_msg(sb, KERN_ERR, "Can't allocate:"
+       mb_debug(sb, "Can't allocate:"
                        " Allocation context details:");
-       ext4_msg(sb, KERN_ERR, "status %u flags 0x%x",
+       mb_debug(sb, "status %u flags 0x%x",
                        ac->ac_status, ac->ac_flags);
-       ext4_msg(sb, KERN_ERR, "orig %lu/%lu/%lu@%lu, "
+       mb_debug(sb, "orig %lu/%lu/%lu@%lu, "
                        "goal %lu/%lu/%lu@%lu, "
                        "best %lu/%lu/%lu@%lu cr %d",
                        (unsigned long)ac->ac_o_ex.fe_group,
@@ -4217,7 +4209,7 @@ static void ext4_mb_show_ac(struct ext4_allocation_context *ac)
                        (unsigned long)ac->ac_b_ex.fe_len,
                        (unsigned long)ac->ac_b_ex.fe_logical,
                        (int)ac->ac_criteria);
-       ext4_msg(sb, KERN_ERR, "%u found", ac->ac_found);
+       mb_debug(sb, "%u found", ac->ac_found);
        ext4_mb_show_pa(sb);
 }
 #else
@@ -4330,7 +4322,7 @@ ext4_mb_initialize_context(struct ext4_allocation_context *ac,
         * locality group. this is a policy, actually */
        ext4_mb_group_or_file(ac);
 
-       mb_debug(1, "init ac: %u blocks @ %u, goal %u, flags %x, 2^%d, "
+       mb_debug(sb, "init ac: %u blocks @ %u, goal %u, flags 0x%x, 2^%d, "
                        "left: %u/%u, right %u/%u to %swritable\n",
                        (unsigned) ar->len, (unsigned) ar->logical,
                        (unsigned) ar->goal, ac->ac_flags, ac->ac_2order,
@@ -4351,7 +4343,7 @@ ext4_mb_discard_lg_preallocations(struct super_block *sb,
        struct list_head discard_list;
        struct ext4_prealloc_space *pa, *tmp;
 
-       mb_debug(1, "discard locality group preallocation\n");
+       mb_debug(sb, "discard locality group preallocation\n");
 
        INIT_LIST_HEAD(&discard_list);
 

diff --git a/fs/ext4/mballoc.h b/fs/ext4/mballoc.h
index 88c98f1..6b4d17c 100644 (file)
--- a/fs/ext4/mballoc.h
+++ b/fs/ext4/mballoc.h
@@ -24,19 +24,15 @@
 #include "ext4.h"
 
 /*
+ * mb_debug() dynamic printk msgs could be used to debug mballoc code.
  */
 #ifdef CONFIG_EXT4_DEBUG
-extern ushort ext4_mballoc_debug;
-
-#define mb_debug(n, fmt, ...)                                          \
-do {                                                                   \
-       if ((n) <= ext4_mballoc_debug) {                                \
-               printk(KERN_DEBUG "(%s, %d): %s: " fmt,                 \
-                      __FILE__, __LINE__, __func__, ##__VA_ARGS__);    \
-       }                                                               \
-} while (0)
+#define mb_debug(sb, fmt, ...)                                         \
+       pr_debug("[%s/%d] EXT4-fs (%s): (%s, %d): %s: " fmt,            \
+               current->comm, task_pid_nr(current), sb->s_id,          \
+              __FILE__, __LINE__, __func__, ##__VA_ARGS__)
 #else
-#define mb_debug(n, fmt, ...)  no_printk(fmt, ##__VA_ARGS__)
+#define mb_debug(sb, fmt, ...) no_printk(fmt, ##__VA_ARGS__)
 #endif
 
 #define EXT4_MB_HISTORY_ALLOC          1       /* allocation */