Commit 3da28eb1 authored by Trond Myklebust's avatar Trond Myklebust

[PATCH] NFS: Replace nfs_page insertion sort with a radix sort

Signed-off-by: default avatarTrond Myklebust <Trond.Myklebust@netapp.com>
parent c6a556b8
......@@ -135,7 +135,7 @@ nfs_write_inode(struct inode *inode, int sync)
int flags = sync ? FLUSH_WAIT : 0;
int ret;
ret = nfs_commit_inode(inode, 0, 0, flags);
ret = nfs_commit_inode(inode, flags);
if (ret < 0)
return ret;
return 0;
......
......@@ -177,36 +177,6 @@ nfs_release_request(struct nfs_page *req)
nfs_page_free(req);
}
/**
* nfs_list_add_request - Insert a request into a sorted list
* @req: request
* @head: head of list into which to insert the request.
*
* Note that the wb_list is sorted by page index in order to facilitate
* coalescing of requests.
* We use an insertion sort that is optimized for the case of appended
* writes.
*/
void
nfs_list_add_request(struct nfs_page *req, struct list_head *head)
{
struct list_head *pos;
#ifdef NFS_PARANOIA
if (!list_empty(&req->wb_list)) {
printk(KERN_ERR "NFS: Add to list failed!\n");
BUG();
}
#endif
list_for_each_prev(pos, head) {
struct nfs_page *p = nfs_list_entry(pos);
if (p->wb_index < req->wb_index)
break;
}
list_add(&req->wb_list, pos);
req->wb_list_head = head;
}
static int nfs_wait_bit_interruptible(void *word)
{
int ret = 0;
......@@ -291,6 +261,62 @@ nfs_coalesce_requests(struct list_head *head, struct list_head *dst,
return npages;
}
#define NFS_SCAN_MAXENTRIES 16
/**
* nfs_scan_lock_dirty - Scan the radix tree for dirty requests
* @nfsi: NFS inode
* @dst: Destination list
* @idx_start: lower bound of page->index to scan
* @npages: idx_start + npages sets the upper bound to scan.
*
* Moves elements from one of the inode request lists.
* If the number of requests is set to 0, the entire address_space
* starting at index idx_start, is scanned.
* The requests are *not* checked to ensure that they form a contiguous set.
* You must be holding the inode's req_lock when calling this function
*/
int
nfs_scan_lock_dirty(struct nfs_inode *nfsi, struct list_head *dst,
unsigned long idx_start, unsigned int npages)
{
struct nfs_page *pgvec[NFS_SCAN_MAXENTRIES];
struct nfs_page *req;
unsigned long idx_end;
int found, i;
int res;
res = 0;
if (npages == 0)
idx_end = ~0;
else
idx_end = idx_start + npages - 1;
for (;;) {
found = radix_tree_gang_lookup_tag(&nfsi->nfs_page_tree,
(void **)&pgvec[0], idx_start, NFS_SCAN_MAXENTRIES,
NFS_PAGE_TAG_DIRTY);
if (found <= 0)
break;
for (i = 0; i < found; i++) {
req = pgvec[i];
if (req->wb_index > idx_end)
goto out;
idx_start = req->wb_index + 1;
if (nfs_set_page_writeback_locked(req)) {
radix_tree_tag_clear(&nfsi->nfs_page_tree,
req->wb_index, NFS_PAGE_TAG_DIRTY);
nfs_list_remove_request(req);
nfs_list_add_request(req, dst);
res++;
}
}
}
out:
return res;
}
/**
* nfs_scan_list - Scan a list for matching requests
* @head: One of the NFS inode request lists
......
......@@ -352,7 +352,7 @@ int nfs_writepages(struct address_space *mapping, struct writeback_control *wbc)
if (err < 0)
goto out;
}
err = nfs_commit_inode(inode, 0, 0, wb_priority(wbc));
err = nfs_commit_inode(inode, wb_priority(wbc));
if (err > 0) {
wbc->nr_to_write -= err;
err = 0;
......@@ -446,6 +446,8 @@ nfs_mark_request_dirty(struct nfs_page *req)
struct nfs_inode *nfsi = NFS_I(inode);
spin_lock(&nfsi->req_lock);
radix_tree_tag_set(&nfsi->nfs_page_tree,
req->wb_index, NFS_PAGE_TAG_DIRTY);
nfs_list_add_request(req, &nfsi->dirty);
nfsi->ndirty++;
spin_unlock(&nfsi->req_lock);
......@@ -537,12 +539,15 @@ static int
nfs_scan_dirty(struct inode *inode, struct list_head *dst, unsigned long idx_start, unsigned int npages)
{
struct nfs_inode *nfsi = NFS_I(inode);
int res;
res = nfs_scan_list(&nfsi->dirty, dst, idx_start, npages);
nfsi->ndirty -= res;
sub_page_state(nr_dirty,res);
if ((nfsi->ndirty == 0) != list_empty(&nfsi->dirty))
printk(KERN_ERR "NFS: desynchronized value of nfs_i.ndirty.\n");
int res = 0;
if (nfsi->ndirty != 0) {
res = nfs_scan_lock_dirty(nfsi, dst, idx_start, npages);
nfsi->ndirty -= res;
sub_page_state(nr_dirty,res);
if ((nfsi->ndirty == 0) != list_empty(&nfsi->dirty))
printk(KERN_ERR "NFS: desynchronized value of nfs_i.ndirty.\n");
}
return res;
}
......@@ -561,11 +566,14 @@ static int
nfs_scan_commit(struct inode *inode, struct list_head *dst, unsigned long idx_start, unsigned int npages)
{
struct nfs_inode *nfsi = NFS_I(inode);
int res;
res = nfs_scan_list(&nfsi->commit, dst, idx_start, npages);
nfsi->ncommit -= res;
if ((nfsi->ncommit == 0) != list_empty(&nfsi->commit))
printk(KERN_ERR "NFS: desynchronized value of nfs_i.ncommit.\n");
int res = 0;
if (nfsi->ncommit != 0) {
res = nfs_scan_list(&nfsi->commit, dst, idx_start, npages);
nfsi->ncommit -= res;
if ((nfsi->ncommit == 0) != list_empty(&nfsi->commit))
printk(KERN_ERR "NFS: desynchronized value of nfs_i.ncommit.\n");
}
return res;
}
#endif
......@@ -1209,36 +1217,24 @@ static void nfs_commit_rpcsetup(struct list_head *head,
struct nfs_write_data *data, int how)
{
struct rpc_task *task = &data->task;
struct nfs_page *first, *last;
struct nfs_page *first;
struct inode *inode;
loff_t start, end, len;
/* Set up the RPC argument and reply structs
* NB: take care not to mess about with data->commit et al. */
list_splice_init(head, &data->pages);
first = nfs_list_entry(data->pages.next);
last = nfs_list_entry(data->pages.prev);
inode = first->wb_context->dentry->d_inode;
/*
* Determine the offset range of requests in the COMMIT call.
* We rely on the fact that data->pages is an ordered list...
*/
start = req_offset(first);
end = req_offset(last) + last->wb_bytes;
len = end - start;
/* If 'len' is not a 32-bit quantity, pass '0' in the COMMIT call */
if (end >= i_size_read(inode) || len < 0 || len > (~((u32)0) >> 1))
len = 0;
data->inode = inode;
data->cred = first->wb_context->cred;
data->args.fh = NFS_FH(data->inode);
data->args.offset = start;
data->args.count = len;
data->res.count = len;
/* Note: we always request a commit of the entire inode */
data->args.offset = 0;
data->args.count = 0;
data->res.count = 0;
data->res.fattr = &data->fattr;
data->res.verf = &data->verf;
......@@ -1357,8 +1353,7 @@ static int nfs_flush_inode(struct inode *inode, unsigned long idx_start,
}
#if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4)
int nfs_commit_inode(struct inode *inode, unsigned long idx_start,
unsigned int npages, int how)
int nfs_commit_inode(struct inode *inode, int how)
{
struct nfs_inode *nfsi = NFS_I(inode);
LIST_HEAD(head);
......@@ -1366,15 +1361,13 @@ int nfs_commit_inode(struct inode *inode, unsigned long idx_start,
error = 0;
spin_lock(&nfsi->req_lock);
res = nfs_scan_commit(inode, &head, idx_start, npages);
res = nfs_scan_commit(inode, &head, 0, 0);
spin_unlock(&nfsi->req_lock);
if (res) {
res += nfs_scan_commit(inode, &head, 0, 0);
spin_unlock(&nfsi->req_lock);
error = nfs_commit_list(&head, how);
} else
spin_unlock(&nfsi->req_lock);
if (error < 0)
return error;
if (error < 0)
return error;
}
return res;
}
#endif
......@@ -1396,7 +1389,7 @@ int nfs_sync_inode(struct inode *inode, unsigned long idx_start,
error = nfs_flush_inode(inode, idx_start, npages, how);
#if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4)
if (error == 0)
error = nfs_commit_inode(inode, idx_start, npages, how);
error = nfs_commit_inode(inode, how);
#endif
} while (error > 0);
return error;
......
......@@ -395,10 +395,10 @@ extern void nfs_commit_done(struct rpc_task *);
*/
extern int nfs_sync_inode(struct inode *, unsigned long, unsigned int, int);
#if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4)
extern int nfs_commit_inode(struct inode *, unsigned long, unsigned int, int);
extern int nfs_commit_inode(struct inode *, int);
#else
static inline int
nfs_commit_inode(struct inode *inode, unsigned long idx_start, unsigned int npages, int how)
nfs_commit_inode(struct inode *inode, int how)
{
return 0;
}
......
......@@ -22,6 +22,7 @@
/*
* Valid flags for the radix tree
*/
#define NFS_PAGE_TAG_DIRTY 0
#define NFS_PAGE_TAG_WRITEBACK 1
/*
......@@ -31,6 +32,7 @@
#define PG_NEED_COMMIT 1
#define PG_NEED_RESCHED 2
struct nfs_inode;
struct nfs_page {
struct list_head wb_list, /* Defines state of page: */
*wb_list_head; /* read/write/commit */
......@@ -59,8 +61,8 @@ extern void nfs_clear_request(struct nfs_page *req);
extern void nfs_release_request(struct nfs_page *req);
extern void nfs_list_add_request(struct nfs_page *, struct list_head *);
extern int nfs_scan_lock_dirty(struct nfs_inode *nfsi, struct list_head *dst,
unsigned long idx_start, unsigned int npages);
extern int nfs_scan_list(struct list_head *, struct list_head *,
unsigned long, unsigned int);
extern int nfs_coalesce_requests(struct list_head *, struct list_head *,
......@@ -94,6 +96,18 @@ nfs_lock_request(struct nfs_page *req)
return 1;
}
/**
* nfs_list_add_request - Insert a request into a list
* @req: request
* @head: head of list into which to insert the request.
*/
static inline void
nfs_list_add_request(struct nfs_page *req, struct list_head *head)
{
list_add_tail(&req->wb_list, head);
req->wb_list_head = head;
}
/**
* nfs_list_remove_request - Remove a request from its wb_list
......
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