diff mbox series

[v2,3/5] ext4: add MB_NUM_ORDERS macro

Message ID 20210209202857.4185846-4-harshadshirwadkar@gmail.com
State Superseded
Headers show
Series [v2,1/5] ext4: drop s_mb_bal_lock and convert protected fields to atomic | expand

Commit Message

harshad shirwadkar Feb. 9, 2021, 8:28 p.m. UTC 
A few arrays in mballoc.c use the total number of valid orders as
their size. Currently, this value is set as "sb->s_blocksize_bits +
2". This makes code harder to read. So, instead add a new macro
MB_NUM_ORDERS(sb) to make the code more readable.

Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
---
 fs/ext4/mballoc.c | 15 ++++++++-------
 fs/ext4/mballoc.h |  5 +++++
 2 files changed, 13 insertions(+), 7 deletions(-)

Comments

Artem Blagodarenko Feb. 16, 2021, 10:45 a.m. UTC | #1 
Hello Harshad,

I believe there are two places yet there number could be changed to the macros

fs/ext4/mballoc.c <<ext4_mb_init_cache>>
             (sb->s_blocksize_bits+2));

fs/ext4/mballoc.c <<ext4_mb_good_group>>
if (ac->ac_2order > ac->ac_sb->s_blocksize_bits+1)

Best regards,
Artem Blagodarenko

> On 9 Feb 2021, at 23:28, Harshad Shirwadkar <harshadshirwadkar@gmail.com> wrote:
> 
> A few arrays in mballoc.c use the total number of valid orders as
> their size. Currently, this value is set as "sb->s_blocksize_bits +
> 2". This makes code harder to read. So, instead add a new macro
> MB_NUM_ORDERS(sb) to make the code more readable.
> 
> Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
> Reviewed-by: Andreas Dilger <adilger@dilger.ca>
> ---
> fs/ext4/mballoc.c | 15 ++++++++-------
> fs/ext4/mballoc.h |  5 +++++
> 2 files changed, 13 insertions(+), 7 deletions(-)
> 
> diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
> index fffd0770e930..b7f25120547d 100644
> --- a/fs/ext4/mballoc.c
> +++ b/fs/ext4/mballoc.c
> @@ -756,7 +756,7 @@ mb_set_largest_free_order(struct super_block *sb, struct ext4_group_info *grp)
> 
> 	grp->bb_largest_free_order = -1; /* uninit */
> 
> -	bits = sb->s_blocksize_bits + 1;
> +	bits = MB_NUM_ORDERS(sb) - 1;
> 	for (i = bits; i >= 0; i--) {
> 		if (grp->bb_counters[i] > 0) {
> 			grp->bb_largest_free_order = i;
> @@ -1928,7 +1928,7 @@ void ext4_mb_simple_scan_group(struct ext4_allocation_context *ac,
> 	int max;
> 
> 	BUG_ON(ac->ac_2order <= 0);
> -	for (i = ac->ac_2order; i <= sb->s_blocksize_bits + 1; i++) {
> +	for (i = ac->ac_2order; i < MB_NUM_ORDERS(sb); i++) {
> 		if (grp->bb_counters[i] == 0)
> 			continue;
> 
> @@ -2314,13 +2314,13 @@ ext4_mb_regular_allocator(struct ext4_allocation_context *ac)
> 	 * We also support searching for power-of-two requests only for
> 	 * requests upto maximum buddy size we have constructed.
> 	 */
> -	if (i >= sbi->s_mb_order2_reqs && i <= sb->s_blocksize_bits + 2) {
> +	if (i >= sbi->s_mb_order2_reqs && i <= MB_NUM_ORDERS(sb)) {
> 		/*
> 		 * This should tell if fe_len is exactly power of 2
> 		 */
> 		if ((ac->ac_g_ex.fe_len & (~(1 << (i - 1)))) == 0)
> 			ac->ac_2order = array_index_nospec(i - 1,
> -							   sb->s_blocksize_bits + 2);
> +							   MB_NUM_ORDERS(sb));
> 	}
> 
> 	/* if stream allocation is enabled, use global goal */
> @@ -2850,7 +2850,7 @@ int ext4_mb_init(struct super_block *sb)
> 	unsigned max;
> 	int ret;
> 
> -	i = (sb->s_blocksize_bits + 2) * sizeof(*sbi->s_mb_offsets);
> +	i = MB_NUM_ORDERS(sb) * sizeof(*sbi->s_mb_offsets);
> 
> 	sbi->s_mb_offsets = kmalloc(i, GFP_KERNEL);
> 	if (sbi->s_mb_offsets == NULL) {
> @@ -2858,7 +2858,7 @@ int ext4_mb_init(struct super_block *sb)
> 		goto out;
> 	}
> 
> -	i = (sb->s_blocksize_bits + 2) * sizeof(*sbi->s_mb_maxs);
> +	i = MB_NUM_ORDERS(sb) * sizeof(*sbi->s_mb_maxs);
> 	sbi->s_mb_maxs = kmalloc(i, GFP_KERNEL);
> 	if (sbi->s_mb_maxs == NULL) {
> 		ret = -ENOMEM;
> @@ -2884,7 +2884,8 @@ int ext4_mb_init(struct super_block *sb)
> 		offset_incr = offset_incr >> 1;
> 		max = max >> 1;
> 		i++;
> -	} while (i <= sb->s_blocksize_bits + 1);
> +	} while (i < MB_NUM_ORDERS(sb));
> +
> 
> 	spin_lock_init(&sbi->s_md_lock);
> 	sbi->s_mb_free_pending = 0;
> diff --git a/fs/ext4/mballoc.h b/fs/ext4/mballoc.h
> index 7597330dbdf8..02861406932f 100644
> --- a/fs/ext4/mballoc.h
> +++ b/fs/ext4/mballoc.h
> @@ -78,6 +78,11 @@
>  */
> #define MB_DEFAULT_MAX_INODE_PREALLOC	512
> 
> +/*
> + * Number of valid buddy orders
> + */
> +#define MB_NUM_ORDERS(sb)		((sb)->s_blocksize_bits + 2)
> +
> struct ext4_free_data {
> 	/* this links the free block information from sb_info */
> 	struct list_head		efd_list;
> -- 
> 2.30.0.478.g8a0d178c01-goog
>
harshad shirwadkar Feb. 26, 2021, 2:36 a.m. UTC | #2 
Thanks Artem for pointing that out. I'll fix this in V3.

- Harshad

On Tue, Feb 16, 2021 at 2:45 AM Благодаренко Артём
<artem.blagodarenko@gmail.com> wrote:
>
> Hello Harshad,
>
> I believe there are two places yet there number could be changed to the macros
>
> fs/ext4/mballoc.c <<ext4_mb_init_cache>>
>              (sb->s_blocksize_bits+2));
>
> fs/ext4/mballoc.c <<ext4_mb_good_group>>
> if (ac->ac_2order > ac->ac_sb->s_blocksize_bits+1)
>
> Best regards,
> Artem Blagodarenko
>
> > On 9 Feb 2021, at 23:28, Harshad Shirwadkar <harshadshirwadkar@gmail.com> wrote:
> >
> > A few arrays in mballoc.c use the total number of valid orders as
> > their size. Currently, this value is set as "sb->s_blocksize_bits +
> > 2". This makes code harder to read. So, instead add a new macro
> > MB_NUM_ORDERS(sb) to make the code more readable.
> >
> > Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
> > Reviewed-by: Andreas Dilger <adilger@dilger.ca>
> > ---
> > fs/ext4/mballoc.c | 15 ++++++++-------
> > fs/ext4/mballoc.h |  5 +++++
> > 2 files changed, 13 insertions(+), 7 deletions(-)
> >
> > diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
> > index fffd0770e930..b7f25120547d 100644
> > --- a/fs/ext4/mballoc.c
> > +++ b/fs/ext4/mballoc.c
> > @@ -756,7 +756,7 @@ mb_set_largest_free_order(struct super_block *sb, struct ext4_group_info *grp)
> >
> >       grp->bb_largest_free_order = -1; /* uninit */
> >
> > -     bits = sb->s_blocksize_bits + 1;
> > +     bits = MB_NUM_ORDERS(sb) - 1;
> >       for (i = bits; i >= 0; i--) {
> >               if (grp->bb_counters[i] > 0) {
> >                       grp->bb_largest_free_order = i;
> > @@ -1928,7 +1928,7 @@ void ext4_mb_simple_scan_group(struct ext4_allocation_context *ac,
> >       int max;
> >
> >       BUG_ON(ac->ac_2order <= 0);
> > -     for (i = ac->ac_2order; i <= sb->s_blocksize_bits + 1; i++) {
> > +     for (i = ac->ac_2order; i < MB_NUM_ORDERS(sb); i++) {
> >               if (grp->bb_counters[i] == 0)
> >                       continue;
> >
> > @@ -2314,13 +2314,13 @@ ext4_mb_regular_allocator(struct ext4_allocation_context *ac)
> >        * We also support searching for power-of-two requests only for
> >        * requests upto maximum buddy size we have constructed.
> >        */
> > -     if (i >= sbi->s_mb_order2_reqs && i <= sb->s_blocksize_bits + 2) {
> > +     if (i >= sbi->s_mb_order2_reqs && i <= MB_NUM_ORDERS(sb)) {
> >               /*
> >                * This should tell if fe_len is exactly power of 2
> >                */
> >               if ((ac->ac_g_ex.fe_len & (~(1 << (i - 1)))) == 0)
> >                       ac->ac_2order = array_index_nospec(i - 1,
> > -                                                        sb->s_blocksize_bits + 2);
> > +                                                        MB_NUM_ORDERS(sb));
> >       }
> >
> >       /* if stream allocation is enabled, use global goal */
> > @@ -2850,7 +2850,7 @@ int ext4_mb_init(struct super_block *sb)
> >       unsigned max;
> >       int ret;
> >
> > -     i = (sb->s_blocksize_bits + 2) * sizeof(*sbi->s_mb_offsets);
> > +     i = MB_NUM_ORDERS(sb) * sizeof(*sbi->s_mb_offsets);
> >
> >       sbi->s_mb_offsets = kmalloc(i, GFP_KERNEL);
> >       if (sbi->s_mb_offsets == NULL) {
> > @@ -2858,7 +2858,7 @@ int ext4_mb_init(struct super_block *sb)
> >               goto out;
> >       }
> >
> > -     i = (sb->s_blocksize_bits + 2) * sizeof(*sbi->s_mb_maxs);
> > +     i = MB_NUM_ORDERS(sb) * sizeof(*sbi->s_mb_maxs);
> >       sbi->s_mb_maxs = kmalloc(i, GFP_KERNEL);
> >       if (sbi->s_mb_maxs == NULL) {
> >               ret = -ENOMEM;
> > @@ -2884,7 +2884,8 @@ int ext4_mb_init(struct super_block *sb)
> >               offset_incr = offset_incr >> 1;
> >               max = max >> 1;
> >               i++;
> > -     } while (i <= sb->s_blocksize_bits + 1);
> > +     } while (i < MB_NUM_ORDERS(sb));
> > +
> >
> >       spin_lock_init(&sbi->s_md_lock);
> >       sbi->s_mb_free_pending = 0;
> > diff --git a/fs/ext4/mballoc.h b/fs/ext4/mballoc.h
> > index 7597330dbdf8..02861406932f 100644
> > --- a/fs/ext4/mballoc.h
> > +++ b/fs/ext4/mballoc.h
> > @@ -78,6 +78,11 @@
> >  */
> > #define MB_DEFAULT_MAX_INODE_PREALLOC 512
> >
> > +/*
> > + * Number of valid buddy orders
> > + */
> > +#define MB_NUM_ORDERS(sb)            ((sb)->s_blocksize_bits + 2)
> > +
> > struct ext4_free_data {
> >       /* this links the free block information from sb_info */
> >       struct list_head                efd_list;
> > --
> > 2.30.0.478.g8a0d178c01-goog
> >
>
diff mbox series

Patch

diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index fffd0770e930..b7f25120547d 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -756,7 +756,7 @@  mb_set_largest_free_order(struct super_block *sb, struct ext4_group_info *grp)
 
 	grp->bb_largest_free_order = -1; /* uninit */
 
-	bits = sb->s_blocksize_bits + 1;
+	bits = MB_NUM_ORDERS(sb) - 1;
 	for (i = bits; i >= 0; i--) {
 		if (grp->bb_counters[i] > 0) {
 			grp->bb_largest_free_order = i;
@@ -1928,7 +1928,7 @@  void ext4_mb_simple_scan_group(struct ext4_allocation_context *ac,
 	int max;
 
 	BUG_ON(ac->ac_2order <= 0);
-	for (i = ac->ac_2order; i <= sb->s_blocksize_bits + 1; i++) {
+	for (i = ac->ac_2order; i < MB_NUM_ORDERS(sb); i++) {
 		if (grp->bb_counters[i] == 0)
 			continue;
 
@@ -2314,13 +2314,13 @@  ext4_mb_regular_allocator(struct ext4_allocation_context *ac)
 	 * We also support searching for power-of-two requests only for
 	 * requests upto maximum buddy size we have constructed.
 	 */
-	if (i >= sbi->s_mb_order2_reqs && i <= sb->s_blocksize_bits + 2) {
+	if (i >= sbi->s_mb_order2_reqs && i <= MB_NUM_ORDERS(sb)) {
 		/*
 		 * This should tell if fe_len is exactly power of 2
 		 */
 		if ((ac->ac_g_ex.fe_len & (~(1 << (i - 1)))) == 0)
 			ac->ac_2order = array_index_nospec(i - 1,
-							   sb->s_blocksize_bits + 2);
+							   MB_NUM_ORDERS(sb));
 	}
 
 	/* if stream allocation is enabled, use global goal */
@@ -2850,7 +2850,7 @@  int ext4_mb_init(struct super_block *sb)
 	unsigned max;
 	int ret;
 
-	i = (sb->s_blocksize_bits + 2) * sizeof(*sbi->s_mb_offsets);
+	i = MB_NUM_ORDERS(sb) * sizeof(*sbi->s_mb_offsets);
 
 	sbi->s_mb_offsets = kmalloc(i, GFP_KERNEL);
 	if (sbi->s_mb_offsets == NULL) {
@@ -2858,7 +2858,7 @@  int ext4_mb_init(struct super_block *sb)
 		goto out;
 	}
 
-	i = (sb->s_blocksize_bits + 2) * sizeof(*sbi->s_mb_maxs);
+	i = MB_NUM_ORDERS(sb) * sizeof(*sbi->s_mb_maxs);
 	sbi->s_mb_maxs = kmalloc(i, GFP_KERNEL);
 	if (sbi->s_mb_maxs == NULL) {
 		ret = -ENOMEM;
@@ -2884,7 +2884,8 @@  int ext4_mb_init(struct super_block *sb)
 		offset_incr = offset_incr >> 1;
 		max = max >> 1;
 		i++;
-	} while (i <= sb->s_blocksize_bits + 1);
+	} while (i < MB_NUM_ORDERS(sb));
+
 
 	spin_lock_init(&sbi->s_md_lock);
 	sbi->s_mb_free_pending = 0;
diff --git a/fs/ext4/mballoc.h b/fs/ext4/mballoc.h
index 7597330dbdf8..02861406932f 100644
--- a/fs/ext4/mballoc.h
+++ b/fs/ext4/mballoc.h
@@ -78,6 +78,11 @@ 
  */
 #define MB_DEFAULT_MAX_INODE_PREALLOC	512
 
+/*
+ * Number of valid buddy orders
+ */
+#define MB_NUM_ORDERS(sb)		((sb)->s_blocksize_bits + 2)
+
 struct ext4_free_data {
 	/* this links the free block information from sb_info */
 	struct list_head		efd_list;