[Ocfs2-devel] [PATCH 1/3] ocfs2: Track local alloc bits internally

[Joel Becker <Joel.Becker@oracle.com>]

On Thu, Jul 31, 2008 at 01:42:00PM -0700, Mark Fasheh wrote:
> Do this instead of tracking absolute local alloc size. This avoids
> needless re-calculatiion of bits from bytes in localalloc.c. Additionally,
> the value is now in a more natural unit for internal file system bitmap
> work.
> 
> Signed-off-by: Mark Fasheh <mfasheh@suse.com>

	Much more natural.
Signed-off-by: Joel Becker <joel.becker@oracle.com>

> ---
>  fs/ocfs2/localalloc.c |   34 ++++++++++++----------------------
>  fs/ocfs2/ocfs2.h      |   10 +++++++++-
>  fs/ocfs2/super.c      |    8 +++++---
>  3 files changed, 26 insertions(+), 26 deletions(-)
> 
> diff --git a/fs/ocfs2/localalloc.c b/fs/ocfs2/localalloc.c
> index 28e492e..b05ce66 100644
> --- a/fs/ocfs2/localalloc.c
> +++ b/fs/ocfs2/localalloc.c
> @@ -47,8 +47,6 @@
>  
>  #define OCFS2_LOCAL_ALLOC(dinode)	(&((dinode)->id2.i_lab))
>  
> -static inline int ocfs2_local_alloc_window_bits(struct ocfs2_super *osb);
> -
>  static u32 ocfs2_local_alloc_count_bits(struct ocfs2_dinode *alloc);
>  
>  static int ocfs2_local_alloc_find_clear_bits(struct ocfs2_super *osb,
> @@ -75,21 +73,13 @@ static int ocfs2_local_alloc_new_window(struct ocfs2_super *osb,
>  static int ocfs2_local_alloc_slide_window(struct ocfs2_super *osb,
>  					  struct inode *local_alloc_inode);
>  
> -static inline int ocfs2_local_alloc_window_bits(struct ocfs2_super *osb)
> -{
> -	BUG_ON(osb->s_clustersize_bits > 20);
> -
> -	/* Size local alloc windows by the megabyte */
> -	return osb->local_alloc_size << (20 - osb->s_clustersize_bits);
> -}
> -
>  /*
>   * Tell us whether a given allocation should use the local alloc
>   * file. Otherwise, it has to go to the main bitmap.
>   */
>  int ocfs2_alloc_should_use_local(struct ocfs2_super *osb, u64 bits)
>  {
> -	int la_bits = ocfs2_local_alloc_window_bits(osb);
> +	int la_bits = osb->local_alloc_bits;
>  	int ret = 0;
>  
>  	if (osb->local_alloc_state != OCFS2_LA_ENABLED)
> @@ -120,14 +110,16 @@ int ocfs2_load_local_alloc(struct ocfs2_super *osb)
>  
>  	mlog_entry_void();
>  
> -	if (osb->local_alloc_size == 0)
> +	if (osb->local_alloc_bits == 0)
>  		goto bail;
>  
> -	if (ocfs2_local_alloc_window_bits(osb) >= osb->bitmap_cpg) {
> +	if (osb->local_alloc_bits >= osb->bitmap_cpg) {
>  		mlog(ML_NOTICE, "Requested local alloc window %d is larger "
>  		     "than max possible %u. Using defaults.\n",
> -		     ocfs2_local_alloc_window_bits(osb), (osb->bitmap_cpg - 1));
> -		osb->local_alloc_size = OCFS2_DEFAULT_LOCAL_ALLOC_SIZE;
> +		     osb->local_alloc_bits, (osb->bitmap_cpg - 1));
> +		osb->local_alloc_bits =
> +			ocfs2_megabytes_to_clusters(osb->sb,
> +						    OCFS2_DEFAULT_LOCAL_ALLOC_SIZE);
>  	}
>  
>  	/* read the alloc off disk */
> @@ -190,8 +182,7 @@ bail:
>  	if (inode)
>  		iput(inode);
>  
> -	mlog(0, "Local alloc window bits = %d\n",
> -	     ocfs2_local_alloc_window_bits(osb));
> +	mlog(0, "Local alloc window bits = %d\n", osb->local_alloc_bits);
>  
>  	mlog_exit(status);
>  	return status;
> @@ -490,7 +481,7 @@ int ocfs2_reserve_local_alloc_bits(struct ocfs2_super *osb,
>  		goto bail;
>  	}
>  
> -	if (bits_wanted > ocfs2_local_alloc_window_bits(osb)) {
> +	if (bits_wanted > osb->local_alloc_bits) {
>  		mlog(0, "Asking for more than my max window size!\n");
>  		status = -ENOSPC;
>  		goto bail;
> @@ -803,7 +794,7 @@ static int ocfs2_local_alloc_reserve_for_window(struct ocfs2_super *osb,
>  		goto bail;
>  	}
>  
> -	(*ac)->ac_bits_wanted = ocfs2_local_alloc_window_bits(osb);
> +	(*ac)->ac_bits_wanted = osb->local_alloc_bits;
>  
>  	status = ocfs2_reserve_cluster_bitmap_bits(osb, *ac);
>  	if (status < 0) {
> @@ -849,7 +840,7 @@ static int ocfs2_local_alloc_new_window(struct ocfs2_super *osb,
>  		     "one\n");
>  
>  	mlog(0, "Allocating %u clusters for a new window.\n",
> -	     ocfs2_local_alloc_window_bits(osb));
> +	     osb->local_alloc_bits);
>  
>  	/* Instruct the allocation code to try the most recently used
>  	 * cluster group. We'll re-record the group used this pass
> @@ -859,8 +850,7 @@ static int ocfs2_local_alloc_new_window(struct ocfs2_super *osb,
>  	/* we used the generic suballoc reserve function, but we set
>  	 * everything up nicely, so there's no reason why we can't use
>  	 * the more specific cluster api to claim bits. */
> -	status = ocfs2_claim_clusters(osb, handle, ac,
> -				      ocfs2_local_alloc_window_bits(osb),
> +	status = ocfs2_claim_clusters(osb, handle, ac, osb->local_alloc_bits,
>  				      &cluster_off, &cluster_count);
>  	if (status < 0) {
>  		if (status != -ENOSPC)
> diff --git a/fs/ocfs2/ocfs2.h b/fs/ocfs2/ocfs2.h
> index 1cb814b..3b3a34e 100644
> --- a/fs/ocfs2/ocfs2.h
> +++ b/fs/ocfs2/ocfs2.h
> @@ -250,7 +250,7 @@ struct ocfs2_super
>  	struct ocfs2_journal *journal;
>  	unsigned long osb_commit_interval;
>  
> -	int local_alloc_size;
> +	unsigned int local_alloc_bits;
>  	enum ocfs2_local_alloc_state local_alloc_state;
>  	struct buffer_head *local_alloc_bh;
>  	u64 la_last_gd;
> @@ -552,6 +552,14 @@ static inline unsigned int ocfs2_pages_per_cluster(struct super_block *sb)
>  	return pages_per_cluster;
>  }
>  
> +static inline unsigned int ocfs2_megabytes_to_clusters(struct super_block *sb,
> +						       unsigned int megs)
> +{
> +	BUILD_BUG_ON(OCFS2_MAX_CLUSTERSIZE > 1048576);
> +
> +	return megs << (20 - OCFS2_SB(sb)->s_clustersize_bits);
> +}
> +
>  static inline void ocfs2_init_inode_steal_slot(struct ocfs2_super *osb)
>  {
>  	spin_lock(&osb->osb_lock);
> diff --git a/fs/ocfs2/super.c b/fs/ocfs2/super.c
> index 2560b33..392f6a8 100644
> --- a/fs/ocfs2/super.c
> +++ b/fs/ocfs2/super.c
> @@ -637,7 +637,7 @@ static int ocfs2_fill_super(struct super_block *sb, void *data, int silent)
>  	osb->s_atime_quantum = parsed_options.atime_quantum;
>  	osb->preferred_slot = parsed_options.slot;
>  	osb->osb_commit_interval = parsed_options.commit_interval;
> -	osb->local_alloc_size = parsed_options.localalloc_opt;
> +	osb->local_alloc_bits = ocfs2_megabytes_to_clusters(sb, parsed_options.localalloc_opt);
>  
>  	status = ocfs2_verify_userspace_stack(osb, &parsed_options);
>  	if (status)
> @@ -938,6 +938,7 @@ static int ocfs2_show_options(struct seq_file *s, struct vfsmount *mnt)
>  {
>  	struct ocfs2_super *osb = OCFS2_SB(mnt->mnt_sb);
>  	unsigned long opts = osb->s_mount_opt;
> +	unsigned int local_alloc_megs;
>  
>  	if (opts & OCFS2_MOUNT_HB_LOCAL)
>  		seq_printf(s, ",_netdev,heartbeat=local");
> @@ -970,8 +971,9 @@ static int ocfs2_show_options(struct seq_file *s, struct vfsmount *mnt)
>  		seq_printf(s, ",commit=%u",
>  			   (unsigned) (osb->osb_commit_interval / HZ));
>  
> -	if (osb->local_alloc_size != OCFS2_DEFAULT_LOCAL_ALLOC_SIZE)
> -		seq_printf(s, ",localalloc=%d", osb->local_alloc_size);
> +	local_alloc_megs = osb->local_alloc_bits >> (20 - osb->s_clustersize_bits);
> +	if (local_alloc_megs != OCFS2_DEFAULT_LOCAL_ALLOC_SIZE)
> +		seq_printf(s, ",localalloc=%d", local_alloc_megs);
>  
>  	if (opts & OCFS2_MOUNT_LOCALFLOCKS)
>  		seq_printf(s, ",localflocks,");
> -- 
> 1.5.4.1
> 
> 
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> Ocfs2-devel at oss.oracle.com
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-- 

Life's Little Instruction Book #337

	"Reread your favorite book."

Joel Becker
Principal Software Developer
Oracle
E-mail: joel.becker at oracle.com
Phone: (650) 506-8127