[PATCH 3 of 4] LVM: allow disk to mirror log conversion

[Zdenek Kabelac <zkabelac@redhat.com>]

Dne 10.1.2011 21:56, Jonathan Brassow napsal(a):
> Patch name: lvm-allow-disk-to-mirror-log-conversion.patch
> 
> Add ability to convert disk log to mirrored log
> 
> We can convert between any combination of mirror logs except
> disk -> mirrored.  This patch fixes that.
> Index: LVM2/lib/metadata/mirror.c
> ===================================================================
> --- LVM2.orig/lib/metadata/mirror.c
> +++ LVM2/lib/metadata/mirror.c
> @@ -1322,7 +1322,9 @@ static int _create_mimage_lvs(struct all
>  		}
>  
>  		if (log) {
> -			if (!lv_add_log_segment(ah, m * stripes + 1, img_lvs[m], 0)) {
> +			uint32_t first_area = m * stripes + (log - 1);

Declaration should be at the beginning of the function.

> +
> +			if (!lv_add_log_segment(ah, first_area, img_lvs[m], 0)) {
>  				log_error("Aborting. Failed to add mirror image segment "
>  					  "to %s. Remove new LV and retry.",
>  					  img_lvs[m]->name);

Actually here should be probably  log_verbose() - as the log_error() is
already written by lv_add_log_segment() - and return_0;

Though this appears in many many other place, so not sure if it's worth to fix
it...



> @@ -1760,7 +1762,7 @@ static struct logical_volume *_set_up_mi
>  	}
>  
>  	if ((log_count > 1) &&
> -	    !_form_mirror(cmd, ah, log_lv, log_count-1, 1, 0, region_size, 1)) {
> +	    !_form_mirror(cmd, ah, log_lv, log_count-1, 1, 0, region_size, 2)) {
>  		log_error("Failed to form mirrored log.");
>  		return NULL;
>  	}
> @@ -1792,6 +1794,7 @@ int add_mirror_log(struct cmd_context *c
>  	int in_sync;
>  	struct logical_volume *log_lv;
>  	struct lvinfo info;
> +	int old_log_count;
>  	int r = 0;
>  
>  	if (dm_list_size(&lv->segments) != 1) {
> @@ -1811,6 +1814,11 @@ int add_mirror_log(struct cmd_context *c
>  		return 0;
>  	}
>  
> +	log_lv = first_seg(lv)->log_lv;
> +	old_log_count = (log_lv) ? lv_mirror_count(log_lv) : 0;
> +	if (old_log_count == log_count)
> +		return_0;

return_0  ->  log_error("what is wrong"); return 0


> +
>  	if (!(parallel_areas = build_parallel_areas_from_lv(cmd, lv, 0)))
>  		return_0;
>  
> @@ -1826,13 +1834,24 @@ int add_mirror_log(struct cmd_context *c
>  
>  	/* allocate destination extents */
>  	ah = allocate_extents(lv->vg, NULL, segtype,
> -			      0, 0, log_count, region_size, 0,
> +			      0, 0, log_count - old_log_count, region_size, 0,
>  			      allocatable_pvs, alloc, parallel_areas);
>  	if (!ah) {
>  		log_error("Unable to allocate extents for mirror log.");
>  		return 0;
>  	}
>  
> +	if (old_log_count) {
> +		/* Converting from disk to mirrored log */
> +		if (!_form_mirror(cmd, ah, log_lv, log_count - 1, 1, 0,
> +				  region_size, 1)) {
> +			log_error("Failed to convert mirror log");
> +			return 0;
> +		}
> +		r = 1;
> +		goto out;
> +	}
> +
>  	/* check sync status */
>  	if (lv_mirror_percent(cmd, lv, 0, &sync_percent, NULL) &&
>  	    (sync_percent == PERCENT_100))
> Index: LVM2/tools/lvconvert.c
> ===================================================================
> --- LVM2.orig/tools/lvconvert.c
> +++ LVM2/tools/lvconvert.c
> @@ -718,6 +718,7 @@ static int _lv_update_mirrored_log(struc
>  				    operable_pvs, 0U);
>  }
>  
> +static int _reload_lv(struct cmd_context *cmd, struct logical_volume *lv);
>  static int _lv_update_log_type(struct cmd_context *cmd,
>  			       struct lvconvert_params *lp,
>  			       struct logical_volume *lv,
> @@ -738,14 +739,6 @@ static int _lv_update_log_type(struct cm
>  						  lv->le_count,
>  						  lp->region_size);
>  
> -	/* Add a log where there is none */
> -	if (!old_log_count) {
> -		if (!add_mirror_log(cmd, original_lv, log_count,
> -				    region_size, operable_pvs, lp->alloc))
> -			return_0;
> -		return 1;
> -	}
> -
>  	/* Remove an existing log completely */
>  	if (!log_count) {
>  		if (!remove_mirror_log(cmd, original_lv, operable_pvs,
> @@ -759,9 +752,17 @@ static int _lv_update_log_type(struct cm
>  
>  	/* Adding redundancy to the log */
>  	if (old_log_count < log_count) {
> -		log_error("Adding log redundancy not supported yet.");
> -		log_error("Try converting the log to 'core' first.");
> -		return_0;
> +		if (!add_mirror_log(cmd, original_lv, log_count,
> +				    region_size, operable_pvs, lp->alloc))
> +			return_0;
> +		/*
> +		 * FIXME: This simple approach won't work in cluster mirrors,
> +		 *        but it doesn't matter because we don't support
> +		 *        mirrored logs in cluster mirrors.
> +		 */
> +		if (old_log_count)
> +			return _reload_lv(cmd, log_lv);
> +		return 1;
>  	}
>  
>  	/* Reducing redundancy of the log */
> @@ -1109,7 +1110,8 @@ static int _lvconvert_mirrors_aux(struct
>  
>  		/* FIXME: can't have multiple mlogs. force corelog. */
>  		if (!lv_add_mirrors(cmd, lv,
> -				    new_mimage_count - old_mimage_count, lp->stripes, lp->stripe_size,
> +				    new_mimage_count - old_mimage_count,
> +				    lp->stripes, lp->stripe_size,
>  				    region_size, 0U, operable_pvs, lp->alloc,
>  				    MIRROR_BY_LV)) {
>  			layer_lv = seg_lv(first_seg(lv), 0);
> 
> --
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Zdenek