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pnfs: pnfs_update_layout needs to consider if strict iomode checking is on

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As flexfiles has FF_FLAGS_NO_READ_IO, there is a need to generically
support enforcing that a IOMODE_RW segment will not allow READ I/O.

Signed-off-by: Tom Haynes <loghyr@primarydata.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
This commit is contained in:
Tom Haynes 2016-05-25 07:31:14 -07:00 committed by Anna Schumaker
parent 602c4cd452
commit c7d73af2d2
4 changed files with 61 additions and 25 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
fs/nfs/filelayout/filelayout.c
View File

@ -890,6 +890,7 @@ filelayout_pg_init_read(struct nfs_pageio_descriptor *pgio,
0,
NFS4_MAX_UINT64,
IOMODE_READ,
false,
GFP_KERNEL);
if (IS_ERR(pgio->pg_lseg)) {
pgio->pg_error = PTR_ERR(pgio->pg_lseg);
@ -915,6 +916,7 @@ filelayout_pg_init_write(struct nfs_pageio_descriptor *pgio,
0,
NFS4_MAX_UINT64,
IOMODE_RW,
false,
GFP_NOFS);
if (IS_ERR(pgio->pg_lseg)) {
pgio->pg_error = PTR_ERR(pgio->pg_lseg);

49
fs/nfs/flexfilelayout/flexfilelayout.c
View File

@ -820,6 +820,36 @@ ff_layout_choose_best_ds_for_read(struct pnfs_layout_segment *lseg,
return NULL;
}
static void
ff_layout_pg_get_read(struct nfs_pageio_descriptor *pgio,
struct nfs_page *req,
bool strict_iomode)
{
retry_strict:
pnfs_put_lseg(pgio->pg_lseg);
pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
req->wb_context,
0,
NFS4_MAX_UINT64,
IOMODE_READ,
strict_iomode,
GFP_KERNEL);
if (IS_ERR(pgio->pg_lseg)) {
pgio->pg_error = PTR_ERR(pgio->pg_lseg);
pgio->pg_lseg = NULL;
}
/* If we don't have checking, do get a IOMODE_RW
* segment, and the server wants to avoid READs
* there, then retry!
*/
if (pgio->pg_lseg && !strict_iomode &&
ff_layout_avoid_read_on_rw(pgio->pg_lseg)) {
strict_iomode = true;
goto retry_strict;
}
}
static void
ff_layout_pg_init_read(struct nfs_pageio_descriptor *pgio,
struct nfs_page *req)
@ -830,19 +860,10 @@ ff_layout_pg_init_read(struct nfs_pageio_descriptor *pgio,
int ds_idx;
/* Use full layout for now */
if (!pgio->pg_lseg || ff_layout_avoid_read_on_rw(pgio->pg_lseg)) {
pnfs_put_lseg(pgio->pg_lseg);
pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
req->wb_context,
0,
NFS4_MAX_UINT64,
IOMODE_READ,
GFP_KERNEL);
if (IS_ERR(pgio->pg_lseg)) {
pgio->pg_error = PTR_ERR(pgio->pg_lseg);
pgio->pg_lseg = NULL;
}
}
if (!pgio->pg_lseg)
ff_layout_pg_get_read(pgio, req, false);
else if (ff_layout_avoid_read_on_rw(pgio->pg_lseg))
ff_layout_pg_get_read(pgio, req, true);
/* If no lseg, fall back to read through mds */
if (pgio->pg_lseg == NULL)
@ -894,6 +915,7 @@ ff_layout_pg_init_write(struct nfs_pageio_descriptor *pgio,
0,
NFS4_MAX_UINT64,
IOMODE_RW,
false,
GFP_NOFS);
if (IS_ERR(pgio->pg_lseg)) {
pgio->pg_error = PTR_ERR(pgio->pg_lseg);
@ -952,6 +974,7 @@ ff_layout_pg_get_mirror_count_write(struct nfs_pageio_descriptor *pgio,
0,
NFS4_MAX_UINT64,
IOMODE_RW,
false,
GFP_NOFS);
if (IS_ERR(pgio->pg_lseg)) {
pgio->pg_error = PTR_ERR(pgio->pg_lseg);

34
fs/nfs/pnfs.c
View File

@ -1321,23 +1321,28 @@ out_existing:
/*
* iomode matching rules:
* iomode lseg match
* ----- ----- -----
* ANY READ true
* ANY RW true
* RW READ false
* RW RW true
* READ READ true
* READ RW true
* iomode lseg strict match
* iomode
* ----- ----- ------ -----
* ANY READ N/A true
* ANY RW N/A true
* RW READ N/A false
* RW RW N/A true
* READ READ N/A true
* READ RW true false
* READ RW false true
*/
static bool
pnfs_lseg_range_match(const struct pnfs_layout_range *ls_range,
const struct pnfs_layout_range *range)
const struct pnfs_layout_range *range,
bool strict_iomode)
{
struct pnfs_layout_range range1;
if ((range->iomode == IOMODE_RW &&
ls_range->iomode != IOMODE_RW) ||
(range->iomode != ls_range->iomode &&
strict_iomode == true) ||
!pnfs_lseg_range_intersecting(ls_range, range))
return 0;
@ -1352,7 +1357,8 @@ pnfs_lseg_range_match(const struct pnfs_layout_range *ls_range,
*/
static struct pnfs_layout_segment *
pnfs_find_lseg(struct pnfs_layout_hdr *lo,
struct pnfs_layout_range *range)
struct pnfs_layout_range *range,
bool strict_iomode)
{
struct pnfs_layout_segment *lseg, *ret = NULL;
@ -1361,7 +1367,8 @@ pnfs_find_lseg(struct pnfs_layout_hdr *lo,
list_for_each_entry(lseg, &lo->plh_segs, pls_list) {
if (test_bit(NFS_LSEG_VALID, &lseg->pls_flags) &&
!test_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags) &&
pnfs_lseg_range_match(&lseg->pls_range, range)) {
pnfs_lseg_range_match(&lseg->pls_range, range,
strict_iomode)) {
ret = pnfs_get_lseg(lseg);
break;
}
@ -1478,6 +1485,7 @@ pnfs_update_layout(struct inode *ino,
loff_t pos,
u64 count,
enum pnfs_iomode iomode,
bool strict_iomode,
gfp_t gfp_flags)
{
struct pnfs_layout_range arg = {
@ -1539,7 +1547,7 @@ lookup_again:
goto out_unlock;
}
lseg = pnfs_find_lseg(lo, &arg);
lseg = pnfs_find_lseg(lo, &arg, strict_iomode);
if (lseg) {
trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
PNFS_UPDATE_LAYOUT_FOUND_CACHED);
@ -1883,6 +1891,7 @@ pnfs_generic_pg_init_read(struct nfs_pageio_descriptor *pgio, struct nfs_page *r
req_offset(req),
rd_size,
IOMODE_READ,
false,
GFP_KERNEL);
if (IS_ERR(pgio->pg_lseg)) {
pgio->pg_error = PTR_ERR(pgio->pg_lseg);
@ -1907,6 +1916,7 @@ pnfs_generic_pg_init_write(struct nfs_pageio_descriptor *pgio,
req_offset(req),
wb_size,
IOMODE_RW,
false,
GFP_NOFS);
if (IS_ERR(pgio->pg_lseg)) {
pgio->pg_error = PTR_ERR(pgio->pg_lseg);

1
fs/nfs/pnfs.h
View File

@ -288,6 +288,7 @@ struct pnfs_layout_segment *pnfs_update_layout(struct inode *ino,
loff_t pos,
u64 count,
enum pnfs_iomode iomode,
bool strict_iomode,
gfp_t gfp_flags);
void pnfs_clear_layoutreturn_waitbit(struct pnfs_layout_hdr *lo);