Re: [PATCH -v2] gfs2: fix bitmap declaration

[Steven Whitehouse <swhiteho@redhat.com>]

Hi,

This doesn't apply over the patch which Dave just sent. Can you redo
this against the current GFS2 -nmw tree if it is still required? Thanks,

Steve.

On Wed, 2013-03-06 at 22:29 +0900, Akinobu Mita wrote:
> The bitmap accessed by bitops like set_bit_le and clear_bit_le must
> be aligned to the size of an "unsigned long".  But there are bitmaps
> that are declared as char array.
> 
> This converts these bitmaps to properly declared ones.  And this also
> changes the unit of the local macro JID_BITMAP_OFFSET from bytes to bits
> in order to reduce the conversion of the unit.
> 
> Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
> Cc: Steven Whitehouse <swhiteho@redhat.com>
> Cc: cluster-devel@redhat.com
> Cc: Christine Caulfield <ccaulfie@redhat.com>
> Cc: David Teigland <teigland@redhat.com>
> ---
> * Change from v1
> - fix wrong offsets caused by the change of type of the 'lvb_bits'
>   (detected by kbuild test)
> 
>  fs/gfs2/lock_dlm.c | 34 ++++++++++++++++++----------------
>  1 file changed, 18 insertions(+), 16 deletions(-)
> 
> diff --git a/fs/gfs2/lock_dlm.c b/fs/gfs2/lock_dlm.c
> index 9802de0..4180269 100644
> --- a/fs/gfs2/lock_dlm.c
> +++ b/fs/gfs2/lock_dlm.c
> @@ -461,10 +461,11 @@ static void gdlm_cancel(struct gfs2_glock *gl)
>   * that jid N needs recovery.
>   */
>  
> -#define JID_BITMAP_OFFSET 8 /* 4 byte generation number + 4 byte unused */
> +/* 4 byte generation number + 4 byte unused */
> +#define JID_BITMAP_OFFSET (8 * BITS_PER_BYTE)
>  
>  static void control_lvb_read(struct lm_lockstruct *ls, uint32_t *lvb_gen,
> -			     char *lvb_bits)
> +			     void *lvb_bits)
>  {
>  	uint32_t gen;
>  	memcpy(lvb_bits, ls->ls_control_lvb, GDLM_LVB_SIZE);
> @@ -473,7 +474,7 @@ static void control_lvb_read(struct lm_lockstruct *ls, uint32_t *lvb_gen,
>  }
>  
>  static void control_lvb_write(struct lm_lockstruct *ls, uint32_t lvb_gen,
> -			      char *lvb_bits)
> +			      void *lvb_bits)
>  {
>  	uint32_t gen;
>  	memcpy(ls->ls_control_lvb, lvb_bits, GDLM_LVB_SIZE);
> @@ -481,13 +482,14 @@ static void control_lvb_write(struct lm_lockstruct *ls, uint32_t lvb_gen,
>  	memcpy(ls->ls_control_lvb, &gen, sizeof(uint32_t));
>  }
>  
> -static int all_jid_bits_clear(char *lvb)
> +static int all_jid_bits_clear(void *lvb)
>  {
> -	int i;
> -	for (i = JID_BITMAP_OFFSET; i < GDLM_LVB_SIZE; i++) {
> -		if (lvb[i])
> -			return 0;
> -	}
> +	unsigned long next_bit = find_next_bit_le(lvb,
> +			GDLM_LVB_SIZE * BITS_PER_BYTE, JID_BITMAP_OFFSET);
> +
> +	if (next_bit < GDLM_LVB_SIZE * BITS_PER_BYTE)
> +		return 0;
> +
>  	return 1;
>  }
>  
> @@ -580,7 +582,7 @@ static void gfs2_control_func(struct work_struct *work)
>  {
>  	struct gfs2_sbd *sdp = container_of(work, struct gfs2_sbd, sd_control_work.work);
>  	struct lm_lockstruct *ls = &sdp->sd_lockstruct;
> -	char lvb_bits[GDLM_LVB_SIZE];
> +	DECLARE_BITMAP(lvb_bits, GDLM_LVB_SIZE * BITS_PER_BYTE);
>  	uint32_t block_gen, start_gen, lvb_gen, flags;
>  	int recover_set = 0;
>  	int write_lvb = 0;
> @@ -664,10 +666,10 @@ static void gfs2_control_func(struct work_struct *work)
>  
>  			ls->ls_recover_result[i] = 0;
>  
> -			if (!test_bit_le(i, lvb_bits + JID_BITMAP_OFFSET))
> +			if (!test_bit_le(JID_BITMAP_OFFSET + i, lvb_bits))
>  				continue;
>  
> -			__clear_bit_le(i, lvb_bits + JID_BITMAP_OFFSET);
> +			__clear_bit_le(JID_BITMAP_OFFSET + i, lvb_bits);
>  			write_lvb = 1;
>  		}
>  	}
> @@ -691,7 +693,7 @@ static void gfs2_control_func(struct work_struct *work)
>  				continue;
>  			if (ls->ls_recover_submit[i] < start_gen) {
>  				ls->ls_recover_submit[i] = 0;
> -				__set_bit_le(i, lvb_bits + JID_BITMAP_OFFSET);
> +				__set_bit_le(JID_BITMAP_OFFSET + i, lvb_bits);
>  			}
>  		}
>  		/* even if there are no bits to set, we need to write the
> @@ -725,7 +727,7 @@ static void gfs2_control_func(struct work_struct *work)
>  	 */
>  
>  	for (i = 0; i < recover_size; i++) {
> -		if (test_bit_le(i, lvb_bits + JID_BITMAP_OFFSET)) {
> +		if (test_bit_le(JID_BITMAP_OFFSET + i, lvb_bits)) {
>  			fs_info(sdp, "recover generation %u jid %d\n",
>  				start_gen, i);
>  			gfs2_recover_set(sdp, i);
> @@ -758,7 +760,7 @@ static void gfs2_control_func(struct work_struct *work)
>  static int control_mount(struct gfs2_sbd *sdp)
>  {
>  	struct lm_lockstruct *ls = &sdp->sd_lockstruct;
> -	char lvb_bits[GDLM_LVB_SIZE];
> +	DECLARE_BITMAP(lvb_bits, GDLM_LVB_SIZE * BITS_PER_BYTE);
>  	uint32_t start_gen, block_gen, mount_gen, lvb_gen;
>  	int mounted_mode;
>  	int retries = 0;
> @@ -949,7 +951,7 @@ static int dlm_recovery_wait(void *word)
>  static int control_first_done(struct gfs2_sbd *sdp)
>  {
>  	struct lm_lockstruct *ls = &sdp->sd_lockstruct;
> -	char lvb_bits[GDLM_LVB_SIZE];
> +	DECLARE_BITMAP(lvb_bits, GDLM_LVB_SIZE * BITS_PER_BYTE);
>  	uint32_t start_gen, block_gen;
>  	int error;
>