mirror of https://gitee.com/openkylin/linux.git
exofs: Prepare for groups
* Rename _offset_dev_unit_off() to _calc_stripe_info() and recieve a struct for the output params * In _prepare_for_striping we only need to call _calc_stripe_info() once. The other componets are easy to calculate from that. This code was inspired by what's done in truncate. * Some code shifts that make sense now but will make more sense when group support is added. Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
This commit is contained in:
Boaz Harrosh
parent
96391e2bae
commit
b367e78bd1
155
fs/exofs/ios.c
155
fs/exofs/ios.c
|
|
@ -259,28 +259,46 @@ int exofs_check_io(struct exofs_io_state *ios, u64 *resid)
|
|||
return acumulated_lin_err;
|
||||
}
|
||||
|
||||
/* REMOVEME: After review
|
||||
Some quoteing from the standard
|
||||
/*
|
||||
* L - logical offset into the file
|
||||
*
|
||||
* U - The number of bytes in a full stripe
|
||||
*
|
||||
* U = stripe_unit * group_width
|
||||
*
|
||||
* N - The stripe number
|
||||
*
|
||||
* N = L / U
|
||||
*
|
||||
* C - The component index coresponding to L
|
||||
*
|
||||
* C = (L - (N*U)) / stripe_unit
|
||||
*
|
||||
* O - The component offset coresponding to L
|
||||
*
|
||||
* (N*stripe_unit)+(L%stripe_unit)
|
||||
*/
|
||||
|
||||
L = logical offset into the file
|
||||
W = number of data components in a stripe
|
||||
S = W * stripe_unit (S is Stripe length)
|
||||
N = L / S (N is the stripe Number)
|
||||
C = (L-(N*S)) / stripe_unit (C is the component)
|
||||
O = (N*stripe_unit)+(L%stripe_unit) (O is the object's offset)
|
||||
*/
|
||||
struct _striping_info {
|
||||
u64 obj_offset;
|
||||
unsigned dev;
|
||||
unsigned unit_off;
|
||||
};
|
||||
|
||||
static void _offset_dev_unit_off(struct exofs_io_state *ios, u64 file_offset,
|
||||
u64 *obj_offset, unsigned *dev, unsigned *unit_off)
|
||||
static void _calc_stripe_info(struct exofs_io_state *ios, u64 file_offset,
|
||||
struct _striping_info *si)
|
||||
{
|
||||
unsigned stripe_unit = ios->layout->stripe_unit;
|
||||
unsigned stripe_length = stripe_unit * ios->layout->group_width;
|
||||
u64 stripe_no = file_offset;
|
||||
unsigned stripe_mod = do_div(stripe_no, stripe_length);
|
||||
u32 stripe_unit = ios->layout->stripe_unit;
|
||||
u32 group_width = ios->layout->group_width;
|
||||
u32 U = stripe_unit * group_width;
|
||||
|
||||
*unit_off = stripe_mod % stripe_unit;
|
||||
*obj_offset = stripe_no * stripe_unit + *unit_off;
|
||||
*dev = stripe_mod / stripe_unit * ios->layout->mirrors_p1;
|
||||
u32 LmodU;
|
||||
u64 N = div_u64_rem(file_offset, U, &LmodU);
|
||||
|
||||
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;
|
||||
}
|
||||
|
||||
static int _add_stripe_unit(struct exofs_io_state *ios, unsigned *cur_pg,
|
||||
|
|
@ -327,65 +345,88 @@ static int _add_stripe_unit(struct exofs_io_state *ios, unsigned *cur_pg,
|
|||
return 0;
|
||||
}
|
||||
|
||||
static int _prepare_for_striping(struct exofs_io_state *ios)
|
||||
static int _prepare_pages(struct exofs_io_state *ios,
|
||||
struct _striping_info *si)
|
||||
{
|
||||
u64 length = ios->length;
|
||||
u64 offset = ios->offset;
|
||||
unsigned stripe_unit = ios->layout->stripe_unit;
|
||||
unsigned mirrors_p1 = ios->layout->mirrors_p1;
|
||||
unsigned dev = si->dev;
|
||||
unsigned comp = 0;
|
||||
unsigned stripes = 0;
|
||||
unsigned cur_pg = 0;
|
||||
int ret = 0;
|
||||
|
||||
if (!ios->pages) {
|
||||
if (ios->kern_buff) {
|
||||
struct exofs_per_dev_state *per_dev = &ios->per_dev[0];
|
||||
unsigned unit_off;
|
||||
|
||||
_offset_dev_unit_off(ios, offset, &per_dev->offset,
|
||||
&per_dev->dev, &unit_off);
|
||||
/* no cross device without page array */
|
||||
BUG_ON((ios->layout->group_width > 1) &&
|
||||
(unit_off + length > stripe_unit));
|
||||
}
|
||||
ios->numdevs = ios->layout->mirrors_p1;
|
||||
return 0;
|
||||
}
|
||||
|
||||
while (length) {
|
||||
struct exofs_per_dev_state *per_dev = &ios->per_dev[comp];
|
||||
unsigned cur_len, page_off;
|
||||
unsigned cur_len, page_off = 0;
|
||||
|
||||
if (!per_dev->length) {
|
||||
unsigned unit_off;
|
||||
per_dev->dev = dev;
|
||||
if (dev < si->dev) {
|
||||
per_dev->offset = si->obj_offset + stripe_unit -
|
||||
si->unit_off;
|
||||
cur_len = stripe_unit;
|
||||
} else if (dev == si->dev) {
|
||||
per_dev->offset = si->obj_offset;
|
||||
cur_len = stripe_unit - si->unit_off;
|
||||
page_off = si->unit_off & ~PAGE_MASK;
|
||||
BUG_ON(page_off && (page_off != ios->pgbase));
|
||||
} else { /* dev > si->dev */
|
||||
per_dev->offset = si->obj_offset - si->unit_off;
|
||||
cur_len = stripe_unit;
|
||||
}
|
||||
|
||||
_offset_dev_unit_off(ios, offset, &per_dev->offset,
|
||||
&per_dev->dev, &unit_off);
|
||||
stripes++;
|
||||
cur_len = min_t(u64, stripe_unit - unit_off, length);
|
||||
offset += cur_len;
|
||||
page_off = unit_off & ~PAGE_MASK;
|
||||
BUG_ON(page_off != ios->pgbase);
|
||||
|
||||
dev += mirrors_p1;
|
||||
dev %= ios->layout->s_numdevs;
|
||||
} else {
|
||||
cur_len = min_t(u64, stripe_unit, length);
|
||||
page_off = 0;
|
||||
cur_len = stripe_unit;
|
||||
}
|
||||
if (cur_len >= length)
|
||||
cur_len = length;
|
||||
|
||||
ret = _add_stripe_unit(ios, &cur_pg, page_off , per_dev,
|
||||
cur_len);
|
||||
if (unlikely(ret))
|
||||
goto out;
|
||||
|
||||
comp += ios->layout->mirrors_p1;
|
||||
comp += mirrors_p1;
|
||||
comp %= ios->layout->s_numdevs;
|
||||
|
||||
length -= cur_len;
|
||||
}
|
||||
out:
|
||||
ios->numdevs = stripes * ios->layout->mirrors_p1;
|
||||
ios->numdevs = stripes * mirrors_p1;
|
||||
return ret;
|
||||
}
|
||||
|
||||
static int _prepare_for_striping(struct exofs_io_state *ios)
|
||||
{
|
||||
struct _striping_info si;
|
||||
|
||||
_calc_stripe_info(ios, ios->offset, &si);
|
||||
|
||||
if (!ios->pages) {
|
||||
if (ios->kern_buff) {
|
||||
struct exofs_per_dev_state *per_dev = &ios->per_dev[0];
|
||||
|
||||
per_dev->offset = si.obj_offset;
|
||||
per_dev->dev = si.dev;
|
||||
|
||||
/* no cross device without page array */
|
||||
BUG_ON((ios->layout->group_width > 1) &&
|
||||
(si.unit_off + ios->length >
|
||||
ios->layout->stripe_unit));
|
||||
}
|
||||
ios->numdevs = ios->layout->mirrors_p1;
|
||||
return 0;
|
||||
}
|
||||
|
||||
return _prepare_pages(ios, &si);
|
||||
}
|
||||
|
||||
int exofs_sbi_create(struct exofs_io_state *ios)
|
||||
{
|
||||
int i, ret;
|
||||
|
|
@ -648,9 +689,7 @@ int exofs_oi_truncate(struct exofs_i_info *oi, u64 size)
|
|||
struct osd_attr attr;
|
||||
__be64 newsize;
|
||||
} *size_attrs;
|
||||
u64 this_obj_size;
|
||||
unsigned dev;
|
||||
unsigned unit_off;
|
||||
struct _striping_info si;
|
||||
int i, ret;
|
||||
|
||||
ret = exofs_get_io_state(&sbi->layout, &ios);
|
||||
|
|
@ -668,19 +707,19 @@ int exofs_oi_truncate(struct exofs_i_info *oi, u64 size)
|
|||
ios->cred = oi->i_cred;
|
||||
|
||||
ios->numdevs = ios->layout->s_numdevs;
|
||||
_offset_dev_unit_off(ios, size, &this_obj_size, &dev, &unit_off);
|
||||
_calc_stripe_info(ios, size, &si);
|
||||
|
||||
for (i = 0; i < ios->layout->group_width; ++i) {
|
||||
struct exofs_trunc_attr *size_attr = &size_attrs[i];
|
||||
u64 obj_size;
|
||||
|
||||
if (i < dev)
|
||||
obj_size = this_obj_size +
|
||||
ios->layout->stripe_unit - unit_off;
|
||||
else if (i == dev)
|
||||
obj_size = this_obj_size;
|
||||
else /* i > dev */
|
||||
obj_size = this_obj_size - unit_off;
|
||||
if (i < si.dev)
|
||||
obj_size = si.obj_offset +
|
||||
ios->layout->stripe_unit - si.unit_off;
|
||||
else if (i == si.dev)
|
||||
obj_size = si.obj_offset;
|
||||
else /* i > si.dev */
|
||||
obj_size = si.obj_offset - si.unit_off;
|
||||
|
||||
size_attr->newsize = cpu_to_be64(obj_size);
|
||||
size_attr->attr = g_attr_logical_length;
|
||||
|
|
|
|||
Loading…
Reference in New Issue