From: Andy Adamson <andros@xxxxxxxxxx>
Remove the pnfs_alloc_layout call to put_layout_locked under the i_lock.
Combine the search for an lseg range with the potential allocation of the
pnfs_layout_type. Return a referenced layout segment or NULL with a reference
taken on the layout in preparation for a layoutget call
Signed-off-by: Andy Adamson <andros@xxxxxxxxxx>
---
fs/nfs/pnfs.c | 117 +++++++++++++++++++++------------------------------------
1 files changed, 43 insertions(+), 74 deletions(-)
diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index fd979ec..77e6671 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -863,40 +863,6 @@ alloc_init_layout(struct inode *ino)
}
/*
- * Retrieve and possibly allocate the inode layout
- *
- * ino->i_lock must be taken by the caller.
- */
-static struct pnfs_layout_type *
-pnfs_alloc_layout(struct inode *ino)
-{
- struct nfs_inode *nfsi = NFS_I(ino);
- struct pnfs_layout_type *new = NULL;
-
- dprintk("%s Begin ino=%p layout=%p\n", __func__, ino, nfsi->layout);
-
- BUG_ON_UNLOCKED_INO(ino);
- if (likely(nfsi->layout))
- return nfsi->layout;
-
- spin_unlock(&ino->i_lock);
- new = alloc_init_layout(ino);
- spin_lock(&ino->i_lock);
-
- if (likely(nfsi->layout == NULL)) { /* Won the race? */
- nfsi->layout = new;
- } else if (new) {
- /* Reference the layout accross i_lock release and grab */
- get_layout(nfsi->layout);
- spin_unlock(&ino->i_lock);
- NFS_SERVER(ino)->pnfs_curr_ld->ld_io_ops->free_layout(new);
- spin_lock(&ino->i_lock);
- put_layout_locked(nfsi->layout);
- }
- return nfsi->layout;
-}
-
-/*
* iomode matching rules:
* range lseg match
* ----- ----- -----
@@ -915,28 +881,52 @@ has_matching_lseg(struct pnfs_layout_segment *lseg,
}
/*
- * lookup range in layout
+ * Lookup range in layout. Return a referenced layout segment or
+ * NULL with a reference on the layout in preparation for a layoutget call.
*/
static struct pnfs_layout_segment *
-pnfs_has_layout(struct pnfs_layout_type *lo,
- struct nfs4_pnfs_layout_segment *range)
+pnfs_get_layout_segment(struct inode *inode,
+ struct nfs4_pnfs_layout_segment *range)
{
struct pnfs_layout_segment *lseg, *ret = NULL;
+ struct nfs_inode *nfsi = NFS_I(inode);
+ struct pnfs_layout_type *new = NULL;
dprintk("%s:Begin\n", __func__);
-
- BUG_ON_UNLOCKED_LO(lo);
- list_for_each_entry (lseg, &lo->segs, fi_list) {
- if (has_matching_lseg(lseg, range)) {
+ spin_lock(&inode->i_lock);
+ if (nfsi->layout == NULL) {
+ spin_unlock(&inode->i_lock);
+ new = alloc_init_layout(inode);
+ if (new == NULL)
+ goto out;
+ spin_lock(&inode->i_lock);
+ if (NFS_I(inode)->layout == NULL) {
+ NFS_I(inode)->layout = new;
+ new = NULL;
+ }
+ }
+ /* Is there a layout segment covering requested range? */
+ list_for_each_entry(lseg, &NFS_I(inode)->layout->segs, fi_list) {
+ if (has_matching_lseg(lseg, range) && lseg->valid) {
ret = lseg;
get_lseg(ret);
- break;
+ goto out_unlock;
}
if (cmp_layout(range, &lseg->range) > 0)
break;
}
+ /*
+ * No layout segment. Reference the layout for layoutget
+ * (matched in pnfs_layout_release)
+ */
+ get_layout(NFS_I(inode)->layout);
- dprintk("%s:Return lseg %p ref %d valid %d\n",
+out_unlock:
+ spin_unlock(&inode->i_lock);
+ if (new)
+ NFS_SERVER(inode)->pnfs_curr_ld->ld_io_ops->free_layout(new);
+out:
+ dprintk("<-- %s lseg %p ref %d valid %d\n",
__func__, ret, ret ? atomic_read(&ret->kref.refcount) : 0,
ret ? ret->valid : 0);
return ret;
@@ -958,26 +948,10 @@ _pnfs_update_layout(struct inode *ino,
.length = NFS4_MAX_UINT64,
};
struct nfs_inode *nfsi = NFS_I(ino);
- struct pnfs_layout_type *lo;
struct pnfs_layout_segment *lseg = NULL;
*lsegpp = NULL;
- spin_lock(&ino->i_lock);
- lo = pnfs_alloc_layout(ino);
- if (lo == NULL) {
- dprintk("%s ERROR: can't get pnfs_layout_type\n", __func__);
- goto out_unlock;
- }
-
- /* Check to see if the layout for the given range already exists */
- lseg = pnfs_has_layout(lo, &arg);
- if (lseg && !lseg->valid) {
- put_lseg_locked(lseg);
- /* someone is cleaning the layout */
- lseg = NULL;
- goto out_unlock;
- }
-
+ lseg = pnfs_get_layout_segment(ino, &arg);
if (lseg) {
dprintk("%s: Using cached lseg %p for %llu@%llu iomode %d)\n",
__func__,
@@ -985,35 +959,30 @@ _pnfs_update_layout(struct inode *ino,
arg.length,
arg.offset,
arg.iomode);
-
- goto out_unlock;
+ *lsegpp = lseg;
+ goto out;
}
- /* if get layout already failed once goto out */
+ /* if layoutget failed wait pnfs_layout_suspend time to retry */
if (test_bit(lo_fail_bit(iomode), &nfsi->layout->pnfs_layout_state)) {
if (unlikely(nfsi->pnfs_layout_suspend &&
get_seconds() >= nfsi->pnfs_layout_suspend)) {
dprintk("%s: layout_get resumed\n", __func__);
+ spin_lock(&ino->i_lock);
clear_bit(lo_fail_bit(iomode),
&nfsi->layout->pnfs_layout_state);
nfsi->pnfs_layout_suspend = 0;
- } else
- goto out_unlock;
+ spin_unlock(&ino->i_lock);
+ } else {
+ goto out;
+ }
}
- /* Reference the layout for layoutget matched in pnfs_layout_release */
- get_layout(lo);
- spin_unlock(&ino->i_lock);
-
- send_layoutget(ino, ctx, &arg, lsegpp, lo);
+ send_layoutget(ino, ctx, &arg, lsegpp, nfsi->layout);
out:
dprintk("%s end, state 0x%lx lseg %p\n", __func__,
nfsi->layout->pnfs_layout_state, lseg);
return;
-out_unlock:
- *lsegpp = lseg;
- spin_unlock(&ino->i_lock);
- goto out;
}
void
--
1.6.6
--
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