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Merge branch 'writeback'

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This commit is contained in:
Trond Myklebust
2017-08-18 14:51:10 -04:00
parent 55cfcd1211 ce7c252a8c
commit b7561e5186
20 changed files with 378 additions and 410 deletions
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2
fs/nfs/callback_proc.c
View File

@@ -51,7 +51,7 @@ __be32 nfs4_callback_getattr(void *argp, void *resp,
goto out_iput;
res->size = i_size_read(inode);
res->change_attr = delegation->change_attr;
if (nfsi->nrequests != 0)
if (nfs_have_writebacks(inode))
res->change_attr++;
res->ctime = inode->i_ctime;
res->mtime = inode->i_mtime;

2
fs/nfs/delegation.c
View File

@@ -1089,7 +1089,7 @@ bool nfs4_delegation_flush_on_close(const struct inode *inode)
delegation = rcu_dereference(nfsi->delegation);
if (delegation == NULL || !(delegation->type & FMODE_WRITE))
goto out;
if (nfsi->nrequests < delegation->pagemod_limit)
if (atomic_long_read(&nfsi->nrequests) < delegation->pagemod_limit)
ret = false;
out:
rcu_read_unlock();

4
fs/nfs/direct.c
View File

@@ -616,13 +616,13 @@ nfs_direct_write_scan_commit_list(struct inode *inode,
struct list_head *list,
struct nfs_commit_info *cinfo)
{
spin_lock(&cinfo->inode->i_lock);
mutex_lock(&NFS_I(cinfo->inode)->commit_mutex);
#ifdef CONFIG_NFS_V4_1
if (cinfo->ds != NULL && cinfo->ds->nwritten != 0)
NFS_SERVER(inode)->pnfs_curr_ld->recover_commit_reqs(list, cinfo);
#endif
nfs_scan_commit_list(&cinfo->mds->list, list, cinfo, 0);
spin_unlock(&cinfo->inode->i_lock);
mutex_unlock(&NFS_I(cinfo->inode)->commit_mutex);
}
static void nfs_direct_write_reschedule(struct nfs_direct_req *dreq)

10
fs/nfs/inode.c
View File

@@ -1285,7 +1285,6 @@ static bool nfs_file_has_buffered_writers(struct nfs_inode *nfsi)
static unsigned long nfs_wcc_update_inode(struct inode *inode, struct nfs_fattr *fattr)
{
struct nfs_inode *nfsi = NFS_I(inode);
unsigned long ret = 0;
if ((fattr->valid & NFS_ATTR_FATTR_PRECHANGE)
@@ -1315,7 +1314,7 @@ static unsigned long nfs_wcc_update_inode(struct inode *inode, struct nfs_fattr
if ((fattr->valid & NFS_ATTR_FATTR_PRESIZE)
&& (fattr->valid & NFS_ATTR_FATTR_SIZE)
&& i_size_read(inode) == nfs_size_to_loff_t(fattr->pre_size)
&& nfsi->nrequests == 0) {
&& !nfs_have_writebacks(inode)) {
i_size_write(inode, nfs_size_to_loff_t(fattr->size));
ret |= NFS_INO_INVALID_ATTR;
}
@@ -1823,7 +1822,7 @@ static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr)
if (new_isize != cur_isize) {
/* Do we perhaps have any outstanding writes, or has
* the file grown beyond our last write? */
if (nfsi->nrequests == 0 || new_isize > cur_isize) {
if (!nfs_have_writebacks(inode) || new_isize > cur_isize) {
i_size_write(inode, new_isize);
if (!have_writers)
invalid |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA;
@@ -2012,10 +2011,11 @@ static void init_once(void *foo)
INIT_LIST_HEAD(&nfsi->access_cache_entry_lru);
INIT_LIST_HEAD(&nfsi->access_cache_inode_lru);
INIT_LIST_HEAD(&nfsi->commit_info.list);
nfsi->nrequests = 0;
nfsi->commit_info.ncommit = 0;
atomic_long_set(&nfsi->nrequests, 0);
atomic_long_set(&nfsi->commit_info.ncommit, 0);
atomic_set(&nfsi->commit_info.rpcs_out, 0);
init_rwsem(&nfsi->rmdir_sem);
mutex_init(&nfsi->commit_mutex);
nfs4_init_once(nfsi);
}

67
fs/nfs/pagelist.c
View File

@@ -134,19 +134,14 @@ EXPORT_SYMBOL_GPL(nfs_async_iocounter_wait);
/*
* nfs_page_group_lock - lock the head of the page group
* @req - request in group that is to be locked
* @nonblock - if true don't block waiting for lock
*
* this lock must be held if modifying the page group list
* this lock must be held when traversing or modifying the page
* group list
*
* return 0 on success, < 0 on error: -EDELAY if nonblocking or the
* result from wait_on_bit_lock
*
* NOTE: calling with nonblock=false should always have set the
* lock bit (see fs/buffer.c and other uses of wait_on_bit_lock
* with TASK_UNINTERRUPTIBLE), so there is no need to check the result.
* return 0 on success, < 0 on error
*/
int
nfs_page_group_lock(struct nfs_page *req, bool nonblock)
nfs_page_group_lock(struct nfs_page *req)
{
struct nfs_page *head = req->wb_head;
@@ -155,35 +150,10 @@ nfs_page_group_lock(struct nfs_page *req, bool nonblock)
if (!test_and_set_bit(PG_HEADLOCK, &head->wb_flags))
return 0;
if (!nonblock) {
set_bit(PG_CONTENDED1, &head->wb_flags);
smp_mb__after_atomic();
return wait_on_bit_lock(&head->wb_flags, PG_HEADLOCK,
TASK_UNINTERRUPTIBLE);
}
return -EAGAIN;
}
/*
* nfs_page_group_lock_wait - wait for the lock to clear, but don't grab it
* @req - a request in the group
*
* This is a blocking call to wait for the group lock to be cleared.
*/
void
nfs_page_group_lock_wait(struct nfs_page *req)
{
struct nfs_page *head = req->wb_head;
WARN_ON_ONCE(head != head->wb_head);
if (!test_bit(PG_HEADLOCK, &head->wb_flags))
return;
set_bit(PG_CONTENDED1, &head->wb_flags);
smp_mb__after_atomic();
wait_on_bit(&head->wb_flags, PG_HEADLOCK,
TASK_UNINTERRUPTIBLE);
return wait_on_bit_lock(&head->wb_flags, PG_HEADLOCK,
TASK_UNINTERRUPTIBLE);
}
/*
@@ -246,7 +216,7 @@ bool nfs_page_group_sync_on_bit(struct nfs_page *req, unsigned int bit)
{
bool ret;
nfs_page_group_lock(req, false);
nfs_page_group_lock(req);
ret = nfs_page_group_sync_on_bit_locked(req, bit);
nfs_page_group_unlock(req);
@@ -288,9 +258,7 @@ nfs_page_group_init(struct nfs_page *req, struct nfs_page *prev)
inode = page_file_mapping(req->wb_page)->host;
set_bit(PG_INODE_REF, &req->wb_flags);
kref_get(&req->wb_kref);
spin_lock(&inode->i_lock);
NFS_I(inode)->nrequests++;
spin_unlock(&inode->i_lock);
atomic_long_inc(&NFS_I(inode)->nrequests);
}
}
}
@@ -306,14 +274,11 @@ static void
nfs_page_group_destroy(struct kref *kref)
{
struct nfs_page *req = container_of(kref, struct nfs_page, wb_kref);
struct nfs_page *head = req->wb_head;
struct nfs_page *tmp, *next;
/* subrequests must release the ref on the head request */
if (req->wb_head != req)
nfs_release_request(req->wb_head);
if (!nfs_page_group_sync_on_bit(req, PG_TEARDOWN))
return;
goto out;
tmp = req;
do {
@@ -324,6 +289,10 @@ nfs_page_group_destroy(struct kref *kref)
nfs_free_request(tmp);
tmp = next;
} while (tmp != req);
out:
/* subrequests must release the ref on the head request */
if (head != req)
nfs_release_request(head);
}
/**
@@ -465,6 +434,7 @@ void nfs_release_request(struct nfs_page *req)
{
kref_put(&req->wb_kref, nfs_page_group_destroy);
}
EXPORT_SYMBOL_GPL(nfs_release_request);
/**
* nfs_wait_on_request - Wait for a request to complete.
@@ -483,6 +453,7 @@ nfs_wait_on_request(struct nfs_page *req)
return wait_on_bit_io(&req->wb_flags, PG_BUSY,
TASK_UNINTERRUPTIBLE);
}
EXPORT_SYMBOL_GPL(nfs_wait_on_request);
/*
* nfs_generic_pg_test - determine if requests can be coalesced
@@ -1036,7 +1007,7 @@ static int __nfs_pageio_add_request(struct nfs_pageio_descriptor *desc,
unsigned int bytes_left = 0;
unsigned int offset, pgbase;
nfs_page_group_lock(req, false);
nfs_page_group_lock(req);
subreq = req;
bytes_left = subreq->wb_bytes;
@@ -1058,7 +1029,7 @@ static int __nfs_pageio_add_request(struct nfs_pageio_descriptor *desc,
if (mirror->pg_recoalesce)
return 0;
/* retry add_request for this subreq */
nfs_page_group_lock(req, false);
nfs_page_group_lock(req);
continue;
}
@@ -1155,7 +1126,7 @@ int nfs_pageio_add_request(struct nfs_pageio_descriptor *desc,
for (midx = 0; midx < desc->pg_mirror_count; midx++) {
if (midx) {
nfs_page_group_lock(req, false);
nfs_page_group_lock(req);
/* find the last request */
for (lastreq = req->wb_head;

41
fs/nfs/pnfs.c
View File

@@ -529,47 +529,6 @@ pnfs_put_lseg(struct pnfs_layout_segment *lseg)
}
EXPORT_SYMBOL_GPL(pnfs_put_lseg);
static void pnfs_free_lseg_async_work(struct work_struct *work)
{
struct pnfs_layout_segment *lseg;
struct pnfs_layout_hdr *lo;
lseg = container_of(work, struct pnfs_layout_segment, pls_work);
lo = lseg->pls_layout;
pnfs_free_lseg(lseg);
pnfs_put_layout_hdr(lo);
}
static void pnfs_free_lseg_async(struct pnfs_layout_segment *lseg)
{
INIT_WORK(&lseg->pls_work, pnfs_free_lseg_async_work);
schedule_work(&lseg->pls_work);
}
void
pnfs_put_lseg_locked(struct pnfs_layout_segment *lseg)
{
if (!lseg)
return;
assert_spin_locked(&lseg->pls_layout->plh_inode->i_lock);
dprintk("%s: lseg %p ref %d valid %d\n", __func__, lseg,
atomic_read(&lseg->pls_refcount),
test_bit(NFS_LSEG_VALID, &lseg->pls_flags));
if (atomic_dec_and_test(&lseg->pls_refcount)) {
struct pnfs_layout_hdr *lo = lseg->pls_layout;
if (test_bit(NFS_LSEG_VALID, &lseg->pls_flags))
return;
pnfs_layout_remove_lseg(lo, lseg);
if (!pnfs_cache_lseg_for_layoutreturn(lo, lseg)) {
pnfs_get_layout_hdr(lo);
pnfs_free_lseg_async(lseg);
}
}
}
/*
* is l2 fully contained in l1?
* start1 end1

2
fs/nfs/pnfs.h
View File

@@ -67,7 +67,6 @@ struct pnfs_layout_segment {
u32 pls_seq;
unsigned long pls_flags;
struct pnfs_layout_hdr *pls_layout;
struct work_struct pls_work;
};
enum pnfs_try_status {
@@ -230,7 +229,6 @@ extern int nfs4_proc_layoutreturn(struct nfs4_layoutreturn *lrp, bool sync);
/* pnfs.c */
void pnfs_get_layout_hdr(struct pnfs_layout_hdr *lo);
void pnfs_put_lseg(struct pnfs_layout_segment *lseg);
void pnfs_put_lseg_locked(struct pnfs_layout_segment *lseg);
void set_pnfs_layoutdriver(struct nfs_server *, const struct nfs_fh *, struct nfs_fsinfo *);
void unset_pnfs_layoutdriver(struct nfs_server *);

37
fs/nfs/pnfs_nfs.c
View File

@@ -83,7 +83,7 @@ pnfs_generic_clear_request_commit(struct nfs_page *req,
}
out:
nfs_request_remove_commit_list(req, cinfo);
pnfs_put_lseg_locked(freeme);
pnfs_put_lseg(freeme);
}
EXPORT_SYMBOL_GPL(pnfs_generic_clear_request_commit);
@@ -91,21 +91,30 @@ static int
pnfs_generic_transfer_commit_list(struct list_head *src, struct list_head *dst,
struct nfs_commit_info *cinfo, int max)
{
struct nfs_page *req, *tmp;
struct nfs_page *req;
int ret = 0;
list_for_each_entry_safe(req, tmp, src, wb_list) {
if (!nfs_lock_request(req))
continue;
while(!list_empty(src)) {
req = list_first_entry(src, struct nfs_page, wb_list);
kref_get(&req->wb_kref);
if (cond_resched_lock(&cinfo->inode->i_lock))
list_safe_reset_next(req, tmp, wb_list);
if (!nfs_lock_request(req)) {
int status;
mutex_unlock(&NFS_I(cinfo->inode)->commit_mutex);
status = nfs_wait_on_request(req);
nfs_release_request(req);
mutex_lock(&NFS_I(cinfo->inode)->commit_mutex);
if (status < 0)
break;
continue;
}
nfs_request_remove_commit_list(req, cinfo);
clear_bit(PG_COMMIT_TO_DS, &req->wb_flags);
nfs_list_add_request(req, dst);
ret++;
if ((ret == max) && !cinfo->dreq)
break;
cond_resched();
}
return ret;
}
@@ -119,7 +128,7 @@ pnfs_generic_scan_ds_commit_list(struct pnfs_commit_bucket *bucket,
struct list_head *dst = &bucket->committing;
int ret;
lockdep_assert_held(&cinfo->inode->i_lock);
lockdep_assert_held(&NFS_I(cinfo->inode)->commit_mutex);
ret = pnfs_generic_transfer_commit_list(src, dst, cinfo, max);
if (ret) {
cinfo->ds->nwritten -= ret;
@@ -127,7 +136,7 @@ pnfs_generic_scan_ds_commit_list(struct pnfs_commit_bucket *bucket,
if (bucket->clseg == NULL)
bucket->clseg = pnfs_get_lseg(bucket->wlseg);
if (list_empty(src)) {
pnfs_put_lseg_locked(bucket->wlseg);
pnfs_put_lseg(bucket->wlseg);
bucket->wlseg = NULL;
}
}
@@ -142,7 +151,7 @@ int pnfs_generic_scan_commit_lists(struct nfs_commit_info *cinfo,
{
int i, rv = 0, cnt;
lockdep_assert_held(&cinfo->inode->i_lock);
lockdep_assert_held(&NFS_I(cinfo->inode)->commit_mutex);
for (i = 0; i < cinfo->ds->nbuckets && max != 0; i++) {
cnt = pnfs_generic_scan_ds_commit_list(&cinfo->ds->buckets[i],
cinfo, max);
@@ -162,7 +171,7 @@ void pnfs_generic_recover_commit_reqs(struct list_head *dst,
int nwritten;
int i;
lockdep_assert_held(&cinfo->inode->i_lock);
lockdep_assert_held(&NFS_I(cinfo->inode)->commit_mutex);
restart:
for (i = 0, b = cinfo->ds->buckets; i < cinfo->ds->nbuckets; i++, b++) {
nwritten = pnfs_generic_transfer_commit_list(&b->written,
@@ -953,12 +962,12 @@ pnfs_layout_mark_request_commit(struct nfs_page *req,
struct list_head *list;
struct pnfs_commit_bucket *buckets;
spin_lock(&cinfo->inode->i_lock);
mutex_lock(&NFS_I(cinfo->inode)->commit_mutex);
buckets = cinfo->ds->buckets;
list = &buckets[ds_commit_idx].written;
if (list_empty(list)) {
if (!pnfs_is_valid_lseg(lseg)) {
spin_unlock(&cinfo->inode->i_lock);
mutex_unlock(&NFS_I(cinfo->inode)->commit_mutex);
cinfo->completion_ops->resched_write(cinfo, req);
return;
}
@@ -975,7 +984,7 @@ pnfs_layout_mark_request_commit(struct nfs_page *req,
cinfo->ds->nwritten++;
nfs_request_add_commit_list_locked(req, list, cinfo);
spin_unlock(&cinfo->inode->i_lock);
mutex_unlock(&NFS_I(cinfo->inode)->commit_mutex);
nfs_mark_page_unstable(req->wb_page, cinfo);
}
EXPORT_SYMBOL_GPL(pnfs_layout_mark_request_commit);

444
fs/nfs/write.c
View File

@@ -154,6 +154,14 @@ static void nfs_context_set_write_error(struct nfs_open_context *ctx, int error)
set_bit(NFS_CONTEXT_ERROR_WRITE, &ctx->flags);
}
static struct nfs_page *
nfs_page_private_request(struct page *page)
{
if (!PagePrivate(page))
return NULL;
return (struct nfs_page *)page_private(page);
}
/*
* nfs_page_find_head_request_locked - find head request associated with @page
*
@@ -162,21 +170,41 @@ static void nfs_context_set_write_error(struct nfs_open_context *ctx, int error)
* returns matching head request with reference held, or NULL if not found.
*/
static struct nfs_page *
nfs_page_find_head_request_locked(struct nfs_inode *nfsi, struct page *page)
nfs_page_find_private_request(struct page *page)
{
struct nfs_page *req = NULL;
if (PagePrivate(page))
req = (struct nfs_page *)page_private(page);
else if (unlikely(PageSwapCache(page)))
req = nfs_page_search_commits_for_head_request_locked(nfsi,
page);
struct address_space *mapping = page_file_mapping(page);
struct nfs_page *req;
if (!PagePrivate(page))
return NULL;
spin_lock(&mapping->private_lock);
req = nfs_page_private_request(page);
if (req) {
WARN_ON_ONCE(req->wb_head != req);
kref_get(&req->wb_kref);
}
spin_unlock(&mapping->private_lock);
return req;
}
static struct nfs_page *
nfs_page_find_swap_request(struct page *page)
{
struct inode *inode = page_file_mapping(page)->host;
struct nfs_inode *nfsi = NFS_I(inode);
struct nfs_page *req = NULL;
if (!PageSwapCache(page))
return NULL;
mutex_lock(&nfsi->commit_mutex);
if (PageSwapCache(page)) {
req = nfs_page_search_commits_for_head_request_locked(nfsi,
page);
if (req) {
WARN_ON_ONCE(req->wb_head != req);
kref_get(&req->wb_kref);
}
}
mutex_unlock(&nfsi->commit_mutex);
return req;
}
@@ -187,12 +215,11 @@ nfs_page_find_head_request_locked(struct nfs_inode *nfsi, struct page *page)
*/
static struct nfs_page *nfs_page_find_head_request(struct page *page)
{
struct inode *inode = page_file_mapping(page)->host;
struct nfs_page *req = NULL;
struct nfs_page *req;
spin_lock(&inode->i_lock);
req = nfs_page_find_head_request_locked(NFS_I(inode), page);
spin_unlock(&inode->i_lock);
req = nfs_page_find_private_request(page);
if (!req)
req = nfs_page_find_swap_request(page);
return req;
}
@@ -241,9 +268,6 @@ nfs_page_group_search_locked(struct nfs_page *head, unsigned int page_offset)
{
struct nfs_page *req;
WARN_ON_ONCE(head != head->wb_head);
WARN_ON_ONCE(!test_bit(PG_HEADLOCK, &head->wb_head->wb_flags));
req = head;
do {
if (page_offset >= req->wb_pgbase &&
@@ -269,20 +293,17 @@ static bool nfs_page_group_covers_page(struct nfs_page *req)
unsigned int pos = 0;
unsigned int len = nfs_page_length(req->wb_page);
nfs_page_group_lock(req, false);
nfs_page_group_lock(req);
do {
for (;;) {
tmp = nfs_page_group_search_locked(req->wb_head, pos);
if (tmp) {
/* no way this should happen */
WARN_ON_ONCE(tmp->wb_pgbase != pos);
pos += tmp->wb_bytes - (pos - tmp->wb_pgbase);
}
} while (tmp && pos < len);
if (!tmp)
break;
pos = tmp->wb_pgbase + tmp->wb_bytes;
}
nfs_page_group_unlock(req);
WARN_ON_ONCE(pos > len);
return pos == len;
return pos >= len;
}
/* We can set the PG_uptodate flag if we see that a write request
@@ -333,8 +354,11 @@ static void nfs_end_page_writeback(struct nfs_page *req)
{
struct inode *inode = page_file_mapping(req->wb_page)->host;
struct nfs_server *nfss = NFS_SERVER(inode);
bool is_done;
if (!nfs_page_group_sync_on_bit(req, PG_WB_END))
is_done = nfs_page_group_sync_on_bit(req, PG_WB_END);
nfs_unlock_request(req);
if (!is_done)
return;
end_page_writeback(req->wb_page);
@@ -342,22 +366,6 @@ static void nfs_end_page_writeback(struct nfs_page *req)
clear_bdi_congested(inode_to_bdi(inode), BLK_RW_ASYNC);
}
/* nfs_page_group_clear_bits
* @req - an nfs request
* clears all page group related bits from @req
*/
static void
nfs_page_group_clear_bits(struct nfs_page *req)
{
clear_bit(PG_TEARDOWN, &req->wb_flags);
clear_bit(PG_UNLOCKPAGE, &req->wb_flags);
clear_bit(PG_UPTODATE, &req->wb_flags);
clear_bit(PG_WB_END, &req->wb_flags);
clear_bit(PG_REMOVE, &req->wb_flags);
}
/*
* nfs_unroll_locks_and_wait - unlock all newly locked reqs and wait on @req
*
@@ -366,43 +374,24 @@ nfs_page_group_clear_bits(struct nfs_page *req)
* @inode - inode associated with request page group, must be holding inode lock
* @head - head request of page group, must be holding head lock
* @req - request that couldn't lock and needs to wait on the req bit lock
* @nonblock - if true, don't actually wait
*
* NOTE: this must be called holding page_group bit lock and inode spin lock
* and BOTH will be released before returning.
* NOTE: this must be called holding page_group bit lock
* which will be released before returning.
*
* returns 0 on success, < 0 on error.
*/
static int
nfs_unroll_locks_and_wait(struct inode *inode, struct nfs_page *head,
struct nfs_page *req, bool nonblock)
__releases(&inode->i_lock)
static void
nfs_unroll_locks(struct inode *inode, struct nfs_page *head,
struct nfs_page *req)
{
struct nfs_page *tmp;
int ret;
/* relinquish all the locks successfully grabbed this run */
for (tmp = head ; tmp != req; tmp = tmp->wb_this_page)
nfs_unlock_request(tmp);
WARN_ON_ONCE(test_bit(PG_TEARDOWN, &req->wb_flags));
/* grab a ref on the request that will be waited on */
kref_get(&req->wb_kref);
nfs_page_group_unlock(head);
spin_unlock(&inode->i_lock);
/* release ref from nfs_page_find_head_request_locked */
nfs_release_request(head);
if (!nonblock)
ret = nfs_wait_on_request(req);
else
ret = -EAGAIN;
nfs_release_request(req);
return ret;
for (tmp = head->wb_this_page ; tmp != req; tmp = tmp->wb_this_page) {
if (!kref_read(&tmp->wb_kref))
continue;
nfs_unlock_and_release_request(tmp);
}
}
/*
@@ -417,7 +406,8 @@ nfs_unroll_locks_and_wait(struct inode *inode, struct nfs_page *head,
*/
static void
nfs_destroy_unlinked_subrequests(struct nfs_page *destroy_list,
struct nfs_page *old_head)
struct nfs_page *old_head,
struct inode *inode)
{
while (destroy_list) {
struct nfs_page *subreq = destroy_list;
@@ -428,33 +418,28 @@ nfs_destroy_unlinked_subrequests(struct nfs_page *destroy_list,
WARN_ON_ONCE(old_head != subreq->wb_head);
/* make sure old group is not used */
subreq->wb_head = subreq;
subreq->wb_this_page = subreq;
clear_bit(PG_REMOVE, &subreq->wb_flags);
/* Note: races with nfs_page_group_destroy() */
if (!kref_read(&subreq->wb_kref)) {
/* Check if we raced with nfs_page_group_destroy() */
if (test_and_clear_bit(PG_TEARDOWN, &subreq->wb_flags))
nfs_free_request(subreq);
continue;
}
subreq->wb_head = subreq;
if (test_and_clear_bit(PG_INODE_REF, &subreq->wb_flags)) {
nfs_release_request(subreq);
atomic_long_dec(&NFS_I(inode)->nrequests);
}
/* subreq is now totally disconnected from page group or any
* write / commit lists. last chance to wake any waiters */
nfs_unlock_request(subreq);
if (!test_bit(PG_TEARDOWN, &subreq->wb_flags)) {
/* release ref on old head request */
nfs_release_request(old_head);
nfs_page_group_clear_bits(subreq);
/* release the PG_INODE_REF reference */
if (test_and_clear_bit(PG_INODE_REF, &subreq->wb_flags))
nfs_release_request(subreq);
else
WARN_ON_ONCE(1);
} else {
WARN_ON_ONCE(test_bit(PG_CLEAN, &subreq->wb_flags));
/* zombie requests have already released the last
* reference and were waiting on the rest of the
* group to complete. Since it's no longer part of a
* group, simply free the request */
nfs_page_group_clear_bits(subreq);
nfs_free_request(subreq);
}
nfs_unlock_and_release_request(subreq);
}
}
@@ -464,7 +449,6 @@ nfs_destroy_unlinked_subrequests(struct nfs_page *destroy_list,
* operations for this page.
*
* @page - the page used to lookup the "page group" of nfs_page structures
* @nonblock - if true, don't block waiting for request locks
*
* This function joins all sub requests to the head request by first
* locking all requests in the group, cancelling any pending operations
@@ -478,7 +462,7 @@ nfs_destroy_unlinked_subrequests(struct nfs_page *destroy_list,
* error was encountered.
*/
static struct nfs_page *
nfs_lock_and_join_requests(struct page *page, bool nonblock)
nfs_lock_and_join_requests(struct page *page)
{
struct inode *inode = page_file_mapping(page)->host;
struct nfs_page *head, *subreq;
@@ -487,43 +471,59 @@ nfs_lock_and_join_requests(struct page *page, bool nonblock)
int ret;
try_again:
total_bytes = 0;
WARN_ON_ONCE(destroy_list);
spin_lock(&inode->i_lock);
/*
* A reference is taken only on the head request which acts as a
* reference to the whole page group - the group will not be destroyed
* until the head reference is released.
*/
head = nfs_page_find_head_request_locked(NFS_I(inode), page);
if (!head) {
spin_unlock(&inode->i_lock);
head = nfs_page_find_head_request(page);
if (!head)
return NULL;
/* lock the page head first in order to avoid an ABBA inefficiency */
if (!nfs_lock_request(head)) {
ret = nfs_wait_on_request(head);
nfs_release_request(head);
if (ret < 0)
return ERR_PTR(ret);
goto try_again;
}
/* holding inode lock, so always make a non-blocking call to try the
* page group lock */
ret = nfs_page_group_lock(head, true);
/* Ensure that nobody removed the request before we locked it */
if (head != nfs_page_private_request(page) && !PageSwapCache(page)) {
nfs_unlock_and_release_request(head);
goto try_again;
}
ret = nfs_page_group_lock(head);
if (ret < 0) {
spin_unlock(&inode->i_lock);
if (!nonblock && ret == -EAGAIN) {
nfs_page_group_lock_wait(head);
nfs_release_request(head);
goto try_again;
}
nfs_release_request(head);
nfs_unlock_and_release_request(head);
return ERR_PTR(ret);
}
/* lock each request in the page group */
subreq = head;
do {
total_bytes = head->wb_bytes;
for (subreq = head->wb_this_page; subreq != head;
subreq = subreq->wb_this_page) {
if (!kref_get_unless_zero(&subreq->wb_kref))
continue;
while (!nfs_lock_request(subreq)) {
/*
* Unlock page to allow nfs_page_group_sync_on_bit()
* to succeed
*/
nfs_page_group_unlock(head);
ret = nfs_wait_on_request(subreq);
if (!ret)
ret = nfs_page_group_lock(head);
if (ret < 0) {
nfs_unroll_locks(inode, head, subreq);
nfs_release_request(subreq);
nfs_unlock_and_release_request(head);
return ERR_PTR(ret);
}
}
/*
* Subrequests are always contiguous, non overlapping
* and in order - but may be repeated (mirrored writes).
@@ -534,25 +534,13 @@ try_again:
} else if (WARN_ON_ONCE(subreq->wb_offset < head->wb_offset ||
((subreq->wb_offset + subreq->wb_bytes) >
(head->wb_offset + total_bytes)))) {
nfs_unroll_locks(inode, head, subreq);
nfs_unlock_and_release_request(subreq);
nfs_page_group_unlock(head);
spin_unlock(&inode->i_lock);
nfs_unlock_and_release_request(head);
return ERR_PTR(-EIO);
}
if (!nfs_lock_request(subreq)) {
/* releases page group bit lock and
* inode spin lock and all references */
ret = nfs_unroll_locks_and_wait(inode, head,
subreq, nonblock);
if (ret == 0)
goto try_again;
return ERR_PTR(ret);
}
subreq = subreq->wb_this_page;
} while (subreq != head);
}
/* Now that all requests are locked, make sure they aren't on any list.
* Commit list removal accounting is done after locks are dropped */
@@ -573,34 +561,30 @@ try_again:
head->wb_bytes = total_bytes;
}
/*
* prepare head request to be added to new pgio descriptor
*/
nfs_page_group_clear_bits(head);
/*
* some part of the group was still on the inode list - otherwise
* the group wouldn't be involved in async write.
* grab a reference for the head request, iff it needs one.
*/
if (!test_and_set_bit(PG_INODE_REF, &head->wb_flags))
/* Postpone destruction of this request */
if (test_and_clear_bit(PG_REMOVE, &head->wb_flags)) {
set_bit(PG_INODE_REF, &head->wb_flags);
kref_get(&head->wb_kref);
atomic_long_inc(&NFS_I(inode)->nrequests);
}
nfs_page_group_unlock(head);
/* drop lock to clean uprequests on destroy list */
spin_unlock(&inode->i_lock);
nfs_destroy_unlinked_subrequests(destroy_list, head, inode);
nfs_destroy_unlinked_subrequests(destroy_list, head);
/* Did we lose a race with nfs_inode_remove_request()? */
if (!(PagePrivate(page) || PageSwapCache(page))) {
nfs_unlock_and_release_request(head);
return NULL;
}
/* still holds ref on head from nfs_page_find_head_request_locked
/* still holds ref on head from nfs_page_find_head_request
* and still has lock on head from lock loop */
return head;
}
static void nfs_write_error_remove_page(struct nfs_page *req)
{
nfs_unlock_request(req);
nfs_end_page_writeback(req);
generic_error_remove_page(page_file_mapping(req->wb_page),
req->wb_page);
@@ -624,12 +608,12 @@ nfs_error_is_fatal_on_server(int err)
* May return an error if the user signalled nfs_wait_on_request().
*/
static int nfs_page_async_flush(struct nfs_pageio_descriptor *pgio,
struct page *page, bool nonblock)
struct page *page)
{
struct nfs_page *req;
int ret = 0;
req = nfs_lock_and_join_requests(page, nonblock);
req = nfs_lock_and_join_requests(page);
if (!req)
goto out;
ret = PTR_ERR(req);
@@ -672,7 +656,7 @@ static int nfs_do_writepage(struct page *page, struct writeback_control *wbc,
int ret;
nfs_pageio_cond_complete(pgio, page_index(page));
ret = nfs_page_async_flush(pgio, page, wbc->sync_mode == WB_SYNC_NONE);
ret = nfs_page_async_flush(pgio, page);
if (ret == -EAGAIN) {
redirty_page_for_writepage(wbc, page);
ret = 0;
@@ -759,6 +743,7 @@ out_err:
*/
static void nfs_inode_add_request(struct inode *inode, struct nfs_page *req)
{
struct address_space *mapping = page_file_mapping(req->wb_page);
struct nfs_inode *nfsi = NFS_I(inode);
WARN_ON_ONCE(req->wb_this_page != req);
@@ -766,27 +751,30 @@ static void nfs_inode_add_request(struct inode *inode, struct nfs_page *req)
/* Lock the request! */
nfs_lock_request(req);
spin_lock(&inode->i_lock);
if (!nfsi->nrequests &&
NFS_PROTO(inode)->have_delegation(inode, FMODE_WRITE))
inode->i_version++;
/*
* Swap-space should not get truncated. Hence no need to plug the race
* with invalidate/truncate.
*/
spin_lock(&mapping->private_lock);
if (!nfs_have_writebacks(inode) &&
NFS_PROTO(inode)->have_delegation(inode, FMODE_WRITE)) {
spin_lock(&inode->i_lock);
inode->i_version++;
spin_unlock(&inode->i_lock);
}
if (likely(!PageSwapCache(req->wb_page))) {
set_bit(PG_MAPPED, &req->wb_flags);
SetPagePrivate(req->wb_page);
set_page_private(req->wb_page, (unsigned long)req);
}
nfsi->nrequests++;
spin_unlock(&mapping->private_lock);
atomic_long_inc(&nfsi->nrequests);
/* this a head request for a page group - mark it as having an
* extra reference so sub groups can follow suit.
* This flag also informs pgio layer when to bump nrequests when
* adding subrequests. */
WARN_ON(test_and_set_bit(PG_INODE_REF, &req->wb_flags));
kref_get(&req->wb_kref);
spin_unlock(&inode->i_lock);
}
/*
@@ -794,25 +782,22 @@ static void nfs_inode_add_request(struct inode *inode, struct nfs_page *req)
*/
static void nfs_inode_remove_request(struct nfs_page *req)
{
struct inode *inode = d_inode(req->wb_context->dentry);
struct address_space *mapping = page_file_mapping(req->wb_page);
struct inode *inode = mapping->host;
struct nfs_inode *nfsi = NFS_I(inode);
struct nfs_page *head;
atomic_long_dec(&nfsi->nrequests);
if (nfs_page_group_sync_on_bit(req, PG_REMOVE)) {
head = req->wb_head;
spin_lock(&inode->i_lock);
spin_lock(&mapping->private_lock);
if (likely(head->wb_page && !PageSwapCache(head->wb_page))) {
set_page_private(head->wb_page, 0);
ClearPagePrivate(head->wb_page);
clear_bit(PG_MAPPED, &head->wb_flags);
}
nfsi->nrequests--;
spin_unlock(&inode->i_lock);
} else {
spin_lock(&inode->i_lock);
nfsi->nrequests--;
spin_unlock(&inode->i_lock);
spin_unlock(&mapping->private_lock);
}
if (test_and_clear_bit(PG_INODE_REF, &req->wb_flags))
@@ -868,7 +853,8 @@ nfs_page_search_commits_for_head_request_locked(struct nfs_inode *nfsi,
* number of outstanding requests requiring a commit as well as
* the MM page stats.
*
* The caller must hold cinfo->inode->i_lock, and the nfs_page lock.
* The caller must hold NFS_I(cinfo->inode)->commit_mutex, and the
* nfs_page lock.
*/
void
nfs_request_add_commit_list_locked(struct nfs_page *req, struct list_head *dst,
@@ -876,7 +862,7 @@ nfs_request_add_commit_list_locked(struct nfs_page *req, struct list_head *dst,
{
set_bit(PG_CLEAN, &req->wb_flags);
nfs_list_add_request(req, dst);
cinfo->mds->ncommit++;
atomic_long_inc(&cinfo->mds->ncommit);
}
EXPORT_SYMBOL_GPL(nfs_request_add_commit_list_locked);
@@ -896,9 +882,9 @@ EXPORT_SYMBOL_GPL(nfs_request_add_commit_list_locked);
void
nfs_request_add_commit_list(struct nfs_page *req, struct nfs_commit_info *cinfo)
{
spin_lock(&cinfo->inode->i_lock);
mutex_lock(&NFS_I(cinfo->inode)->commit_mutex);
nfs_request_add_commit_list_locked(req, &cinfo->mds->list, cinfo);
spin_unlock(&cinfo->inode->i_lock);
mutex_unlock(&NFS_I(cinfo->inode)->commit_mutex);
if (req->wb_page)
nfs_mark_page_unstable(req->wb_page, cinfo);
}
@@ -922,7 +908,7 @@ nfs_request_remove_commit_list(struct nfs_page *req,
if (!test_and_clear_bit(PG_CLEAN, &(req)->wb_flags))
return;
nfs_list_remove_request(req);
cinfo->mds->ncommit--;
atomic_long_dec(&cinfo->mds->ncommit);
}
EXPORT_SYMBOL_GPL(nfs_request_remove_commit_list);
@@ -967,7 +953,7 @@ nfs_clear_page_commit(struct page *page)
WB_RECLAIMABLE);
}
/* Called holding inode (/cinfo) lock */
/* Called holding the request lock on @req */
static void
nfs_clear_request_commit(struct nfs_page *req)
{
@@ -976,9 +962,11 @@ nfs_clear_request_commit(struct nfs_page *req)
struct nfs_commit_info cinfo;
nfs_init_cinfo_from_inode(&cinfo, inode);
mutex_lock(&NFS_I(inode)->commit_mutex);
if (!pnfs_clear_request_commit(req, &cinfo)) {
nfs_request_remove_commit_list(req, &cinfo);
}
mutex_unlock(&NFS_I(inode)->commit_mutex);
nfs_clear_page_commit(req->wb_page);
}
}
@@ -1023,7 +1011,6 @@ static void nfs_write_completion(struct nfs_pgio_header *hdr)
remove_req:
nfs_inode_remove_request(req);
next:
nfs_unlock_request(req);
nfs_end_page_writeback(req);
nfs_release_request(req);
}
@@ -1035,28 +1022,36 @@ out:
unsigned long
nfs_reqs_to_commit(struct nfs_commit_info *cinfo)
{
return cinfo->mds->ncommit;
return atomic_long_read(&cinfo->mds->ncommit);
}
/* cinfo->inode->i_lock held by caller */
/* NFS_I(cinfo->inode)->commit_mutex held by caller */
int
nfs_scan_commit_list(struct list_head *src, struct list_head *dst,
struct nfs_commit_info *cinfo, int max)
{
struct nfs_page *req, *tmp;
struct nfs_page *req;
int ret = 0;
list_for_each_entry_safe(req, tmp, src, wb_list) {
if (!nfs_lock_request(req))
continue;
while(!list_empty(src)) {
req = list_first_entry(src, struct nfs_page, wb_list);
kref_get(&req->wb_kref);
if (cond_resched_lock(&cinfo->inode->i_lock))
list_safe_reset_next(req, tmp, wb_list);
if (!nfs_lock_request(req)) {
int status;
mutex_unlock(&NFS_I(cinfo->inode)->commit_mutex);
status = nfs_wait_on_request(req);
nfs_release_request(req);
mutex_lock(&NFS_I(cinfo->inode)->commit_mutex);
if (status < 0)
break;
continue;
}
nfs_request_remove_commit_list(req, cinfo);
nfs_list_add_request(req, dst);
ret++;
if ((ret == max) && !cinfo->dreq)
break;
cond_resched();
}
return ret;
}
@@ -1076,15 +1071,17 @@ nfs_scan_commit(struct inode *inode, struct list_head *dst,
{
int ret = 0;
spin_lock(&cinfo->inode->i_lock);
if (cinfo->mds->ncommit > 0) {
if (!atomic_long_read(&cinfo->mds->ncommit))
return 0;
mutex_lock(&NFS_I(cinfo->inode)->commit_mutex);
if (atomic_long_read(&cinfo->mds->ncommit) > 0) {
const int max = INT_MAX;
ret = nfs_scan_commit_list(&cinfo->mds->list, dst,
cinfo, max);
ret += pnfs_scan_commit_lists(inode, cinfo, max - ret);
}
spin_unlock(&cinfo->inode->i_lock);
mutex_unlock(&NFS_I(cinfo->inode)->commit_mutex);
return ret;
}
@@ -1105,43 +1102,21 @@ static struct nfs_page *nfs_try_to_update_request(struct inode *inode,
unsigned int end;
int error;
if (!PagePrivate(page))
return NULL;
end = offset + bytes;
spin_lock(&inode->i_lock);
for (;;) {
req = nfs_page_find_head_request_locked(NFS_I(inode), page);
if (req == NULL)
goto out_unlock;
req = nfs_lock_and_join_requests(page);
if (IS_ERR_OR_NULL(req))
return req;
/* should be handled by nfs_flush_incompatible */
WARN_ON_ONCE(req->wb_head != req);
WARN_ON_ONCE(req->wb_this_page != req);
rqend = req->wb_offset + req->wb_bytes;
/*
* Tell the caller to flush out the request if
* the offsets are non-contiguous.
* Note: nfs_flush_incompatible() will already
* have flushed out requests having wrong owners.
*/
if (offset > rqend
|| end < req->wb_offset)
goto out_flushme;
if (nfs_lock_request(req))
break;
/* The request is locked, so wait and then retry */
spin_unlock(&inode->i_lock);
error = nfs_wait_on_request(req);
nfs_release_request(req);
if (error != 0)
goto out_err;
spin_lock(&inode->i_lock);
}
rqend = req->wb_offset + req->wb_bytes;
/*
* Tell the caller to flush out the request if
* the offsets are non-contiguous.
* Note: nfs_flush_incompatible() will already
* have flushed out requests having wrong owners.
*/
if (offset > rqend || end < req->wb_offset)
goto out_flushme;
/* Okay, the request matches. Update the region */
if (offset < req->wb_offset) {
@@ -1152,17 +1127,17 @@ static struct nfs_page *nfs_try_to_update_request(struct inode *inode,
req->wb_bytes = end - req->wb_offset;
else
req->wb_bytes = rqend - req->wb_offset;
out_unlock:
if (req)
nfs_clear_request_commit(req);
spin_unlock(&inode->i_lock);
return req;
out_flushme:
spin_unlock(&inode->i_lock);
nfs_release_request(req);
/*
* Note: we mark the request dirty here because
* nfs_lock_and_join_requests() cannot preserve
* commit flags, so we have to replay the write.
*/
nfs_mark_request_dirty(req);
nfs_unlock_and_release_request(req);
error = nfs_wb_page(inode, page);
out_err:
return ERR_PTR(error);
return (error < 0) ? ERR_PTR(error) : NULL;
}
/*
@@ -1227,8 +1202,6 @@ int nfs_flush_incompatible(struct file *file, struct page *page)
l_ctx = req->wb_lock_context;
do_flush = req->wb_page != page ||
!nfs_match_open_context(req->wb_context, ctx);
/* for now, flush if more than 1 request in page_group */
do_flush |= req->wb_this_page != req;
if (l_ctx && flctx &&
!(list_empty_careful(&flctx->flc_posix) &&
list_empty_careful(&flctx->flc_flock))) {
@@ -1412,7 +1385,6 @@ static void nfs_redirty_request(struct nfs_page *req)
{
nfs_mark_request_dirty(req);
set_bit(NFS_CONTEXT_RESEND_WRITES, &req->wb_context->flags);
nfs_unlock_request(req);
nfs_end_page_writeback(req);
nfs_release_request(req);
}
@@ -1934,7 +1906,7 @@ int nfs_write_inode(struct inode *inode, struct writeback_control *wbc)
int ret = 0;
/* no commits means nothing needs to be done */
if (!nfsi->commit_info.ncommit)
if (!atomic_long_read(&nfsi->commit_info.ncommit))
return ret;
if (wbc->sync_mode == WB_SYNC_NONE) {
@@ -2015,7 +1987,7 @@ int nfs_wb_page_cancel(struct inode *inode, struct page *page)
/* blocking call to cancel all requests and join to a single (head)
* request */
req = nfs_lock_and_join_requests(page, false);
req = nfs_lock_and_join_requests(page);
if (IS_ERR(req)) {
ret = PTR_ERR(req);