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NFS4.1: Add lseg to struct nfs4_fl_commit_bucket
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Also create a commit_info structure to hold the bucket array and push
it up from the lseg to the layout where it really belongs.

While we are at it, fix a refcounting bug due to an (incorrect)
implicit assumption that filelayout_scan_ds_commit_list always
completely emptied the src list.

This clarifies refcounting, removes the ugly find_only_write_lseg
functions, and pushes the file layout commit code along on the path to
supporting multiple lsegs.

Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
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Fred Isaman authored and Trond Myklebust committed Apr 27, 2012
1 parent 1acbbb4 commit 799ba8d
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Showing 2 changed files with 144 additions and 92 deletions.
216 changes: 126 additions & 90 deletions fs/nfs/nfs4filelayout.c
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Original file line number Diff line number Diff line change
Expand Up @@ -650,10 +650,66 @@ filelayout_free_lseg(struct pnfs_layout_segment *lseg)

dprintk("--> %s\n", __func__);
nfs4_fl_put_deviceid(fl->dsaddr);
kfree(fl->commit_buckets);
/* This assumes a single RW lseg */
if (lseg->pls_range.iomode == IOMODE_RW) {
struct nfs4_filelayout *flo;

flo = FILELAYOUT_FROM_HDR(lseg->pls_layout);
flo->commit_info.nbuckets = 0;
kfree(flo->commit_info.buckets);
flo->commit_info.buckets = NULL;
}
_filelayout_free_lseg(fl);
}

static int
filelayout_alloc_commit_info(struct pnfs_layout_segment *lseg,
gfp_t gfp_flags)
{
struct nfs4_filelayout_segment *fl = FILELAYOUT_LSEG(lseg);
struct nfs4_filelayout *flo = FILELAYOUT_FROM_HDR(lseg->pls_layout);

struct nfs4_fl_commit_bucket *buckets;
int size;

if (fl->commit_through_mds)
return 0;
if (flo->commit_info.nbuckets != 0) {
/* This assumes there is only one IOMODE_RW lseg. What
* we really want to do is have a layout_hdr level
* dictionary of <multipath_list4, fh> keys, each
* associated with a struct list_head, populated by calls
* to filelayout_write_pagelist().
* */
return 0;
}

size = (fl->stripe_type == STRIPE_SPARSE) ?
fl->dsaddr->ds_num : fl->dsaddr->stripe_count;

buckets = kcalloc(size, sizeof(struct nfs4_fl_commit_bucket),
gfp_flags);
if (!buckets)
return -ENOMEM;
else {
int i;

spin_lock(&lseg->pls_layout->plh_inode->i_lock);
if (flo->commit_info.nbuckets != 0)
kfree(buckets);
else {
flo->commit_info.buckets = buckets;
flo->commit_info.nbuckets = size;
for (i = 0; i < size; i++) {
INIT_LIST_HEAD(&buckets[i].written);
INIT_LIST_HEAD(&buckets[i].committing);
}
}
spin_unlock(&lseg->pls_layout->plh_inode->i_lock);
return 0;
}
}

static struct pnfs_layout_segment *
filelayout_alloc_lseg(struct pnfs_layout_hdr *layoutid,
struct nfs4_layoutget_res *lgr,
Expand All @@ -673,29 +729,6 @@ filelayout_alloc_lseg(struct pnfs_layout_hdr *layoutid,
_filelayout_free_lseg(fl);
return NULL;
}

/* This assumes there is only one IOMODE_RW lseg. What
* we really want to do is have a layout_hdr level
* dictionary of <multipath_list4, fh> keys, each
* associated with a struct list_head, populated by calls
* to filelayout_write_pagelist().
* */
if ((!fl->commit_through_mds) && (lgr->range.iomode == IOMODE_RW)) {
int i;
int size = (fl->stripe_type == STRIPE_SPARSE) ?
fl->dsaddr->ds_num : fl->dsaddr->stripe_count;

fl->commit_buckets = kcalloc(size, sizeof(struct nfs4_fl_commit_bucket), gfp_flags);
if (!fl->commit_buckets) {
filelayout_free_lseg(&fl->generic_hdr);
return NULL;
}
fl->number_of_buckets = size;
for (i = 0; i < size; i++) {
INIT_LIST_HEAD(&fl->commit_buckets[i].written);
INIT_LIST_HEAD(&fl->commit_buckets[i].committing);
}
}
return &fl->generic_hdr;
}

Expand Down Expand Up @@ -747,6 +780,8 @@ static void
filelayout_pg_init_write(struct nfs_pageio_descriptor *pgio,
struct nfs_page *req)
{
int status;

BUG_ON(pgio->pg_lseg != NULL);

pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
Expand All @@ -757,7 +792,16 @@ filelayout_pg_init_write(struct nfs_pageio_descriptor *pgio,
GFP_NOFS);
/* If no lseg, fall back to write through mds */
if (pgio->pg_lseg == NULL)
nfs_pageio_reset_write_mds(pgio);
goto out_mds;
status = filelayout_alloc_commit_info(pgio->pg_lseg, GFP_NOFS);
if (status < 0) {
put_lseg(pgio->pg_lseg);
pgio->pg_lseg = NULL;
goto out_mds;
}
return;
out_mds:
nfs_pageio_reset_write_mds(pgio);
}

static const struct nfs_pageio_ops filelayout_pg_read_ops = {
Expand Down Expand Up @@ -793,17 +837,13 @@ filelayout_clear_request_commit(struct nfs_page *req)
if (!test_and_clear_bit(PG_COMMIT_TO_DS, &req->wb_flags))
goto out;
if (list_is_singular(&req->wb_list)) {
struct pnfs_layout_segment *lseg;
struct nfs4_fl_commit_bucket *bucket;

/* From here we can find the bucket, but for the moment,
* since there is only one relevant lseg...
*/
list_for_each_entry(lseg, &NFS_I(inode)->layout->plh_segs, pls_list) {
if (lseg->pls_range.iomode == IOMODE_RW) {
freeme = lseg;
break;
}
}
bucket = list_first_entry(&req->wb_list,
struct nfs4_fl_commit_bucket,
written);
freeme = bucket->wlseg;
bucket->wlseg = NULL;
}
out:
nfs_request_remove_commit_list(req);
Expand All @@ -818,6 +858,7 @@ filelayout_choose_commit_list(struct nfs_page *req,
struct nfs4_filelayout_segment *fl = FILELAYOUT_LSEG(lseg);
u32 i, j;
struct list_head *list;
struct nfs4_fl_commit_bucket *buckets;

if (fl->commit_through_mds)
return &NFS_I(req->wb_context->dentry->d_inode)->commit_list;
Expand All @@ -831,15 +872,16 @@ filelayout_choose_commit_list(struct nfs_page *req,
j = nfs4_fl_calc_j_index(lseg,
(loff_t)req->wb_index << PAGE_CACHE_SHIFT);
i = select_bucket_index(fl, j);
list = &fl->commit_buckets[i].written;
buckets = FILELAYOUT_FROM_HDR(lseg->pls_layout)->commit_info.buckets;
list = &buckets[i].written;
if (list_empty(list)) {
/* Non-empty buckets hold a reference on the lseg. That ref
* is normally transferred to the COMMIT call and released
* there. It could also be released if the last req is pulled
* off due to a rewrite, in which case it will be done in
* filelayout_remove_commit_req
* filelayout_clear_request_commit
*/
get_lseg(lseg);
buckets[i].wlseg = get_lseg(lseg);
}
set_bit(PG_COMMIT_TO_DS, &req->wb_flags);
return list;
Expand Down Expand Up @@ -908,32 +950,6 @@ static int filelayout_initiate_commit(struct nfs_write_data *data, int how)
&filelayout_commit_call_ops, how);
}

/*
* This is only useful while we are using whole file layouts.
*/
static struct pnfs_layout_segment *
find_only_write_lseg_locked(struct inode *inode)
{
struct pnfs_layout_segment *lseg;

list_for_each_entry(lseg, &NFS_I(inode)->layout->plh_segs, pls_list)
if (lseg->pls_range.iomode == IOMODE_RW)
return lseg;
return NULL;
}

static struct pnfs_layout_segment *find_only_write_lseg(struct inode *inode)
{
struct pnfs_layout_segment *rv;

spin_lock(&inode->i_lock);
rv = find_only_write_lseg_locked(inode);
if (rv)
get_lseg(rv);
spin_unlock(&inode->i_lock);
return rv;
}

static int
filelayout_scan_ds_commit_list(struct nfs4_fl_commit_bucket *bucket, int max,
spinlock_t *lock)
Expand All @@ -955,6 +971,13 @@ filelayout_scan_ds_commit_list(struct nfs4_fl_commit_bucket *bucket, int max,
if (ret == max)
break;
}
if (ret) {
bucket->clseg = bucket->wlseg;
if (list_empty(src))
bucket->wlseg = NULL;
else
get_lseg(bucket->clseg);
}
return ret;
}

Expand All @@ -964,18 +987,14 @@ filelayout_scan_ds_commit_list(struct nfs4_fl_commit_bucket *bucket, int max,
static int filelayout_scan_commit_lists(struct inode *inode, int max,
spinlock_t *lock)
{
struct pnfs_layout_segment *lseg;
struct nfs4_filelayout_segment *fl;
struct nfs4_fl_commit_info *fl_cinfo;
int i, rv = 0, cnt;

lseg = find_only_write_lseg_locked(inode);
if (!lseg)
goto out_done;
fl = FILELAYOUT_LSEG(lseg);
if (fl->commit_through_mds)
fl_cinfo = &FILELAYOUT_FROM_HDR(NFS_I(inode)->layout)->commit_info;
if (fl_cinfo->nbuckets == 0)
goto out_done;
for (i = 0; i < fl->number_of_buckets && max != 0; i++) {
cnt = filelayout_scan_ds_commit_list(&fl->commit_buckets[i],
for (i = 0; i < fl_cinfo->nbuckets && max != 0; i++) {
cnt = filelayout_scan_ds_commit_list(&fl_cinfo->buckets[i],
max, lock);
max -= cnt;
rv += cnt;
Expand All @@ -987,38 +1006,35 @@ static int filelayout_scan_commit_lists(struct inode *inode, int max,
static unsigned int
alloc_ds_commits(struct inode *inode, struct list_head *list)
{
struct pnfs_layout_segment *lseg;
struct nfs4_filelayout_segment *fl;
struct nfs4_fl_commit_info *fl_cinfo;
struct nfs4_fl_commit_bucket *bucket;
struct nfs_write_data *data;
int i, j;
unsigned int nreq = 0;

/* Won't need this when non-whole file layout segments are supported
* instead we will use a pnfs_layout_hdr structure */
lseg = find_only_write_lseg(inode);
if (!lseg)
return 0;
fl = FILELAYOUT_LSEG(lseg);
for (i = 0; i < fl->number_of_buckets; i++) {
if (list_empty(&fl->commit_buckets[i].committing))
fl_cinfo = &FILELAYOUT_FROM_HDR(NFS_I(inode)->layout)->commit_info;
bucket = fl_cinfo->buckets;
for (i = 0; i < fl_cinfo->nbuckets; i++, bucket++) {
if (list_empty(&bucket->committing))
continue;
data = nfs_commitdata_alloc();
if (!data)
break;
data->ds_commit_index = i;
data->lseg = lseg;
data->lseg = bucket->clseg;
bucket->clseg = NULL;
list_add(&data->pages, list);
nreq++;
}

/* Clean up on error */
for (j = i; j < fl->number_of_buckets; j++) {
if (list_empty(&fl->commit_buckets[i].committing))
for (j = i; j < fl_cinfo->nbuckets; j++, bucket++) {
if (list_empty(&bucket->committing))
continue;
nfs_retry_commit(&fl->commit_buckets[i].committing, lseg);
put_lseg(lseg); /* associated with emptying bucket */
nfs_retry_commit(&bucket->committing, bucket->clseg);
put_lseg(bucket->clseg);
bucket->clseg = NULL;
}
put_lseg(lseg);
/* Caller will clean up entries put on list */
return nreq;
}
Expand Down Expand Up @@ -1058,7 +1074,10 @@ filelayout_commit_pagelist(struct inode *inode, struct list_head *mds_pages,
nfs_initiate_commit(data, NFS_CLIENT(inode),
data->mds_ops, how);
} else {
nfs_init_commit(data, &FILELAYOUT_LSEG(data->lseg)->commit_buckets[data->ds_commit_index].committing, data->lseg);
struct nfs4_fl_commit_info *fl_cinfo;

fl_cinfo = &FILELAYOUT_FROM_HDR(data->lseg->pls_layout)->commit_info;
nfs_init_commit(data, &fl_cinfo->buckets[data->ds_commit_index].committing, data->lseg);
filelayout_initiate_commit(data, how);
}
}
Expand All @@ -1072,10 +1091,27 @@ filelayout_free_deveiceid_node(struct nfs4_deviceid_node *d)
nfs4_fl_free_deviceid(container_of(d, struct nfs4_file_layout_dsaddr, id_node));
}

static struct pnfs_layout_hdr *
filelayout_alloc_layout_hdr(struct inode *inode, gfp_t gfp_flags)
{
struct nfs4_filelayout *flo;

flo = kzalloc(sizeof(*flo), gfp_flags);
return &flo->generic_hdr;
}

static void
filelayout_free_layout_hdr(struct pnfs_layout_hdr *lo)
{
kfree(FILELAYOUT_FROM_HDR(lo));
}

static struct pnfs_layoutdriver_type filelayout_type = {
.id = LAYOUT_NFSV4_1_FILES,
.name = "LAYOUT_NFSV4_1_FILES",
.owner = THIS_MODULE,
.alloc_layout_hdr = filelayout_alloc_layout_hdr,
.free_layout_hdr = filelayout_free_layout_hdr,
.alloc_lseg = filelayout_alloc_lseg,
.free_lseg = filelayout_free_lseg,
.pg_read_ops = &filelayout_pg_read_ops,
Expand Down
20 changes: 18 additions & 2 deletions fs/nfs/nfs4filelayout.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -77,6 +77,13 @@ struct nfs4_file_layout_dsaddr {
struct nfs4_fl_commit_bucket {
struct list_head written;
struct list_head committing;
struct pnfs_layout_segment *wlseg;
struct pnfs_layout_segment *clseg;
};

struct nfs4_fl_commit_info {
int nbuckets;
struct nfs4_fl_commit_bucket *buckets;
};

struct nfs4_filelayout_segment {
Expand All @@ -89,10 +96,19 @@ struct nfs4_filelayout_segment {
struct nfs4_file_layout_dsaddr *dsaddr; /* Point to GETDEVINFO data */
unsigned int num_fh;
struct nfs_fh **fh_array;
struct nfs4_fl_commit_bucket *commit_buckets; /* Sort commits to ds */
int number_of_buckets;
};

struct nfs4_filelayout {
struct pnfs_layout_hdr generic_hdr;
struct nfs4_fl_commit_info commit_info;
};

static inline struct nfs4_filelayout *
FILELAYOUT_FROM_HDR(struct pnfs_layout_hdr *lo)
{
return container_of(lo, struct nfs4_filelayout, generic_hdr);
}

static inline struct nfs4_filelayout_segment *
FILELAYOUT_LSEG(struct pnfs_layout_segment *lseg)
{
Expand Down

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