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Commit 50a76fd3 authored by Boaz Harrosh's avatar Boaz Harrosh
Browse files

exofs: groups support 



* _calc_stripe_info() changes to accommodate for grouping
  calculations. Returns additional information

* old _prepare_pages() becomes _prepare_one_group()
  which stores pages belonging to one device group.

* New _prepare_for_striping iterates on all groups calling
  _prepare_one_group().

* Enable mounting of groups data_maps (group_width != 0)

[QUESTION]
what is faster A or B;
A.	x += stride;
	x = x % width + first_x;

B	x += stride
	if (x < last_x)
		x = first_x;

Signed-off-by: default avatarBoaz Harrosh <bharrosh@panasas.com>
parent b367e78b

fs/exofs/exofs.h

+3 −0
Original line number Diff line number Diff line
@@ -63,6 +63,8 @@ struct exofs_layout { 
	unsigned mirrors_p1;



	unsigned group_width;

	u64	 group_depth;

	unsigned group_count;



	enum exofs_inode_layout_gen_functions lay_func;
@@ -132,6 +134,7 @@ struct exofs_io_state { 
	struct page		**pages;

	unsigned		nr_pages;

	unsigned		pgbase;

	unsigned		pages_consumed;



	/* Attributes */

	unsigned		in_attr_len;

fs/exofs/ios.c

+106 −23
Original line number Diff line number Diff line
@@ -262,25 +262,50 @@ int exofs_check_io(struct exofs_io_state *ios, u64 *resid) 
/*

 * L - logical offset into the file

 *

 * U - The number of bytes in a full stripe

 * U - The number of bytes in a stripe within a group

 *

 *	U = stripe_unit * group_width

 *

 * N - The stripe number

 * T - The number of bytes striped within a group of component objects

 *     (before advancing to the next group)

 *

 *	N = L / U

 *	T = stripe_unit * group_width * group_depth

 *

 * S - The number of bytes striped across all component objects

 *     before the pattern repeats

 *

 *	S = stripe_unit * group_width * group_depth * group_count

 *

 * M - The "major" (i.e., across all components) stripe number

 *

 *	M = L / S

 *

 * G - Counts the groups from the beginning of the major stripe

 *

 *	G = (L - (M * S)) / T	[or (L % S) / T]

 *

 * H - The byte offset within the group

 *

 *	H = (L - (M * S)) % T	[or (L % S) % T]

 *

 * N - The "minor" (i.e., across the group) stripe number

 *

 *	N = H / U

 *

 * C - The component index coresponding to L

 *

 *	C = (L - (N*U)) / stripe_unit

 *	C = (H - (N * U)) / stripe_unit + G * group_width

 *	[or (L % U) / stripe_unit + G * group_width]

 *

 * O - The component offset coresponding to L

 *

 *	(N*stripe_unit)+(L%stripe_unit)

 *	O = L % stripe_unit + N * stripe_unit + M * group_depth * stripe_unit

 */



struct _striping_info {

	u64 obj_offset;

	u64 group_length;

	u64 total_group_length;

	u64 Major;

	unsigned dev;

	unsigned unit_off;

};
@@ -290,15 +315,35 @@ static void _calc_stripe_info(struct exofs_io_state *ios, u64 file_offset, 
{

	u32	stripe_unit = ios->layout->stripe_unit;

	u32	group_width = ios->layout->group_width;

	u64	group_depth = ios->layout->group_depth;



	u32	U = stripe_unit * group_width;

	u64	T = U * group_depth;

	u64	S = T * ios->layout->group_count;

	u64	M = div64_u64(file_offset, S);



	u32	LmodU;

	u64 	N = div_u64_rem(file_offset, U, &LmodU);

	/*

	G = (L - (M * S)) / T

	H = (L - (M * S)) % T

	*/

	u64	LmodS = file_offset - M * S;

	u32	G = div64_u64(LmodS, T);

	u64	H = LmodS - G * T;



	si->unit_off = LmodU % stripe_unit;

	si->obj_offset = N * stripe_unit + si->unit_off;

	si->dev = LmodU / stripe_unit;

	u32	N = div_u64(H, U);



	/* "H - (N * U)" is just "H % U" so it's bound to u32 */

	si->dev = (u32)(H - (N * U)) / stripe_unit + G * group_width;

	si->dev *= ios->layout->mirrors_p1;



	div_u64_rem(file_offset, stripe_unit, &si->unit_off);



	si->obj_offset = si->unit_off + (N * stripe_unit) +

				  (M * group_depth * stripe_unit);



	si->group_length = T - H;

	si->total_group_length = T;

	si->Major = M;

}



static int _add_stripe_unit(struct exofs_io_state *ios,  unsigned *cur_pg,
@@ -345,16 +390,17 @@ static int _add_stripe_unit(struct exofs_io_state *ios, unsigned *cur_pg, 
	return 0;

}



static int _prepare_pages(struct exofs_io_state *ios,

			  struct _striping_info *si)

static int _prepare_one_group(struct exofs_io_state *ios, u64 length,

			      struct _striping_info *si, unsigned first_comp)

{

	u64 length = ios->length;

	unsigned stripe_unit = ios->layout->stripe_unit;

	unsigned mirrors_p1 = ios->layout->mirrors_p1;

	unsigned devs_in_group = ios->layout->group_width * mirrors_p1;

	unsigned dev = si->dev;

	unsigned comp = 0;

	unsigned stripes = 0;

	unsigned cur_pg = 0;

	unsigned first_dev = dev - (dev % devs_in_group);

	unsigned comp = first_comp + (dev - first_dev);

	unsigned max_comp = ios->numdevs ? ios->numdevs - mirrors_p1 : 0;

	unsigned cur_pg = ios->pages_consumed;

	int ret = 0;



	while (length) {
@@ -377,10 +423,11 @@ static int _prepare_pages(struct exofs_io_state *ios, 
				cur_len = stripe_unit;

			}



			stripes++;

			if (max_comp < comp)

				max_comp = comp;



			dev += mirrors_p1;

			dev %= ios->layout->s_numdevs;

			dev = (dev % devs_in_group) + first_dev;

		} else {

			cur_len = stripe_unit;

		}
@@ -393,18 +440,24 @@ static int _prepare_pages(struct exofs_io_state *ios, 
			goto out;



		comp += mirrors_p1;

		comp %= ios->layout->s_numdevs;

		comp = (comp % devs_in_group) + first_comp;



		length -= cur_len;

	}

out:

	ios->numdevs = stripes * mirrors_p1;

	ios->numdevs = max_comp + mirrors_p1;

	ios->pages_consumed = cur_pg;

	return ret;

}



static int _prepare_for_striping(struct exofs_io_state *ios)

{

	u64 length = ios->length;

	struct _striping_info si;

	unsigned devs_in_group = ios->layout->group_width *

				 ios->layout->mirrors_p1;

	unsigned first_comp = 0;

	int ret = 0;



	_calc_stripe_info(ios, ios->offset, &si);
@@ -424,7 +477,31 @@ static int _prepare_for_striping(struct exofs_io_state *ios) 
		return 0;

	}



	return _prepare_pages(ios, &si);

	while (length) {

		if (length < si.group_length)

			si.group_length = length;



		ret = _prepare_one_group(ios, si.group_length, &si, first_comp);

		if (unlikely(ret))

			goto out;



		length -= si.group_length;



		si.group_length = si.total_group_length;

		si.unit_off = 0;

		++si.Major;

		si.obj_offset = si.Major * ios->layout->stripe_unit *

						ios->layout->group_depth;



		si.dev = (si.dev - (si.dev % devs_in_group)) + devs_in_group;

		si.dev %= ios->layout->s_numdevs;



		first_comp += devs_in_group;

		first_comp %= ios->layout->s_numdevs;

	}



out:

	return ret;

}



int exofs_sbi_create(struct exofs_io_state *ios)
@@ -482,6 +559,9 @@ static int _sbi_write_mirror(struct exofs_io_state *ios, int cur_comp) 
	unsigned last_comp = cur_comp + ios->layout->mirrors_p1;

	int ret = 0;



	if (ios->pages && !master_dev->length)

		return 0; /* Just an empty slot */



	for (; cur_comp < last_comp; ++cur_comp, ++dev) {

		struct exofs_per_dev_state *per_dev = &ios->per_dev[cur_comp];

		struct osd_request *or;
@@ -580,6 +660,9 @@ static int _sbi_read_mirror(struct exofs_io_state *ios, unsigned cur_comp) 
	struct exofs_per_dev_state *per_dev = &ios->per_dev[cur_comp];

	unsigned first_dev = (unsigned)ios->obj.id;



	if (ios->pages && !per_dev->length)

		return 0; /* Just an empty slot */



	first_dev = per_dev->dev + first_dev % ios->layout->mirrors_p1;

	or = osd_start_request(exofs_ios_od(ios, first_dev), GFP_KERNEL);

	if (unlikely(!or)) {

fs/exofs/super.c

+32 −14
Original line number Diff line number Diff line
@@ -323,11 +323,7 @@ static int _read_and_match_data_map(struct exofs_sb_info *sbi, unsigned numdevs, 
	sbi->data_map.odm_raid_algorithm  =

				le32_to_cpu(dt->dt_data_map.cb_raid_algorithm);



/* FIXME: Only raid0 !group_width/depth for now. if not so, do not mount */

	if (sbi->data_map.odm_group_width || sbi->data_map.odm_group_depth) {

		EXOFS_ERR("Group width/depth not supported\n");

		return -EINVAL;

	}

/* FIXME: Only raid0 for now. if not so, do not mount */

	if (sbi->data_map.odm_num_comps != numdevs) {

		EXOFS_ERR("odm_num_comps(%u) != numdevs(%u)\n",

			  sbi->data_map.odm_num_comps, numdevs);
@@ -343,14 +339,6 @@ static int _read_and_match_data_map(struct exofs_sb_info *sbi, unsigned numdevs, 
		return -EINVAL;

	}



	stripe_length = sbi->data_map.odm_stripe_unit *

			(numdevs / (sbi->data_map.odm_mirror_cnt + 1));

	if (stripe_length >= (1ULL << 32)) {

		EXOFS_ERR("Total Stripe length(0x%llx)"

			  " >= 32bit is not supported\n", _LLU(stripe_length));

		return -EINVAL;

	}



	if (0 != (sbi->data_map.odm_stripe_unit & ~PAGE_MASK)) {

		EXOFS_ERR("Stripe Unit(0x%llx)"

			  " must be Multples of PAGE_SIZE(0x%lx)\n",
@@ -360,8 +348,36 @@ static int _read_and_match_data_map(struct exofs_sb_info *sbi, unsigned numdevs, 


	sbi->layout.stripe_unit = sbi->data_map.odm_stripe_unit;

	sbi->layout.mirrors_p1 = sbi->data_map.odm_mirror_cnt + 1;



	if (sbi->data_map.odm_group_width) {

		sbi->layout.group_width = sbi->data_map.odm_group_width;

		sbi->layout.group_depth = sbi->data_map.odm_group_depth;

		if (!sbi->layout.group_depth) {

			EXOFS_ERR("group_depth == 0 && group_width != 0\n");

			return -EINVAL;

		}

		sbi->layout.group_count = sbi->data_map.odm_num_comps /

						sbi->layout.mirrors_p1 /

						sbi->data_map.odm_group_width;

	} else {

		if (sbi->data_map.odm_group_depth) {

			printk(KERN_NOTICE "Warning: group_depth ignored "

				"group_width == 0 && group_depth == %d\n",

				sbi->data_map.odm_group_depth);

			sbi->data_map.odm_group_depth = 0;

		}

		sbi->layout.group_width = sbi->data_map.odm_num_comps /

							sbi->layout.mirrors_p1;

		sbi->layout.group_depth = -1;

		sbi->layout.group_count = 1;

	}



	stripe_length = (u64)sbi->layout.group_width * sbi->layout.stripe_unit;

	if (stripe_length >= (1ULL << 32)) {

		EXOFS_ERR("Total Stripe length(0x%llx)"

			  " >= 32bit is not supported\n", _LLU(stripe_length));

		return -EINVAL;

	}



	return 0;

}
@@ -540,6 +556,8 @@ static int exofs_fill_super(struct super_block *sb, void *data, int silent) 
	sbi->layout.stripe_unit = PAGE_SIZE;

	sbi->layout.mirrors_p1 = 1;

	sbi->layout.group_width = 1;

	sbi->layout.group_depth = -1;

	sbi->layout.group_count = 1;

	sbi->layout.s_ods[0] = od;

	sbi->layout.s_numdevs = 1;

	sbi->layout.s_pid = opts->pid;