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author | Boaz Harrosh <bharrosh@panasas.com> | 2010-02-11 13:01:39 +0200 |
---|---|---|
committer | Boaz Harrosh <bharrosh@panasas.com> | 2010-02-28 03:55:53 -0800 |
commit | 50a76fd3c352ed2740eba01512efcfceee0703be (patch) | |
tree | 425416e068648e225b41327a120d00bbddd16d0e /fs/exofs/ios.c | |
parent | b367e78bd1c7af4c018ce98b1f6d3e001aba895a (diff) | |
download | op-kernel-dev-50a76fd3c352ed2740eba01512efcfceee0703be.zip op-kernel-dev-50a76fd3c352ed2740eba01512efcfceee0703be.tar.gz |
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: Boaz Harrosh <bharrosh@panasas.com>
Diffstat (limited to 'fs/exofs/ios.c')
-rw-r--r-- | fs/exofs/ios.c | 129 |
1 files changed, 106 insertions, 23 deletions
diff --git a/fs/exofs/ios.c b/fs/exofs/ios.c index d28febd..5293bc4 100644 --- a/fs/exofs/ios.c +++ b/fs/exofs/ios.c @@ -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); + + /* + 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; + + 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; - u32 LmodU; - u64 N = div_u64_rem(file_offset, U, &LmodU); + div_u64_rem(file_offset, stripe_unit, &si->unit_off); - si->unit_off = LmodU % stripe_unit; - si->obj_offset = N * stripe_unit + si->unit_off; - si->dev = LmodU / stripe_unit; - si->dev *= ios->layout->mirrors_p1; + 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)) { |