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Commit cc6e5340 authored by Fred Isaman's avatar Fred Isaman Committed by Trond Myklebust
Browse files

pnfs: change lo refcounting to atomic_t 



This will be required to allow us to grab reference outside of i_lock.
While we are at it, make put_layout_hdr take the same argument as all the
related functions.

Signed-off-by: default avatarFred Isaman <iisaman@netapp.com>
Signed-off-by: default avatarTrond Myklebust <Trond.Myklebust@netapp.com>
parent fc1794c5

fs/nfs/pnfs.c

+26 −22
Original line number Diff line number Diff line
@@ -177,35 +177,39 @@ EXPORT_SYMBOL_GPL(pnfs_unregister_layoutdriver); 
 * pNFS client layout cache

 */



/* Need to hold i_lock if caller does not already hold reference */

static void

get_layout_hdr_locked(struct pnfs_layout_hdr *lo)

get_layout_hdr(struct pnfs_layout_hdr *lo)

{

	assert_spin_locked(&lo->plh_inode->i_lock);

	lo->plh_refcount++;

	atomic_inc(&lo->plh_refcount);

}



static void

put_layout_hdr_locked(struct pnfs_layout_hdr *lo)

destroy_layout_hdr(struct pnfs_layout_hdr *lo)

{

	assert_spin_locked(&lo->plh_inode->i_lock);

	BUG_ON(lo->plh_refcount == 0);



	lo->plh_refcount--;

	if (!lo->plh_refcount) {

	dprintk("%s: freeing layout cache %p\n", __func__, lo);

	BUG_ON(!list_empty(&lo->plh_layouts));

	NFS_I(lo->plh_inode)->layout = NULL;

	kfree(lo);

}



static void

put_layout_hdr_locked(struct pnfs_layout_hdr *lo)

{

	if (atomic_dec_and_test(&lo->plh_refcount))

		destroy_layout_hdr(lo);

}



void

put_layout_hdr(struct inode *inode)

put_layout_hdr(struct pnfs_layout_hdr *lo)

{

	spin_lock(&inode->i_lock);

	put_layout_hdr_locked(NFS_I(inode)->layout);

	struct inode *inode = lo->plh_inode;



	if (atomic_dec_and_lock(&lo->plh_refcount, &inode->i_lock)) {

		destroy_layout_hdr(lo);

		spin_unlock(&inode->i_lock);

	}

}



static void

init_lseg(struct pnfs_layout_hdr *lo, struct pnfs_layout_segment *lseg)
@@ -223,7 +227,7 @@ static void free_lseg(struct pnfs_layout_segment *lseg) 


	NFS_SERVER(ino)->pnfs_curr_ld->free_lseg(lseg);

	/* Matched by get_layout_hdr in pnfs_insert_layout */

	put_layout_hdr(ino);

	put_layout_hdr(NFS_I(ino)->layout);

}



/* The use of tmp_list is necessary because pnfs_curr_ld->free_lseg
@@ -490,7 +494,7 @@ pnfs_insert_layout(struct pnfs_layout_hdr *lo, 
			__func__, lseg, lseg->pls_range.iomode,

			lseg->pls_range.offset, lseg->pls_range.length);

	}

	get_layout_hdr_locked(lo);

	get_layout_hdr(lo);



	dprintk("%s:Return\n", __func__);

}
@@ -503,7 +507,7 @@ alloc_init_layout_hdr(struct inode *ino) 
	lo = kzalloc(sizeof(struct pnfs_layout_hdr), GFP_KERNEL);

	if (!lo)

		return NULL;

	lo->plh_refcount = 1;

	atomic_set(&lo->plh_refcount, 1);

	INIT_LIST_HEAD(&lo->plh_layouts);

	INIT_LIST_HEAD(&lo->plh_segs);

	lo->plh_inode = ino;
@@ -618,7 +622,7 @@ pnfs_update_layout(struct inode *ino, 
		goto out_unlock;

	atomic_inc(&lo->plh_outstanding);



	get_layout_hdr_locked(lo);

	get_layout_hdr(lo);

	if (list_empty(&lo->plh_segs)) {

		/* The lo must be on the clp list if there is any

		 * chance of a CB_LAYOUTRECALL(FILE) coming in.
@@ -641,7 +645,7 @@ pnfs_update_layout(struct inode *ino, 
		spin_unlock(&ino->i_lock);

	}

	atomic_dec(&lo->plh_outstanding);

	put_layout_hdr(ino);

	put_layout_hdr(lo);

out:

	dprintk("%s end, state 0x%lx lseg %p\n", __func__,

		nfsi->layout->plh_flags, lseg);

fs/nfs/pnfs.h

+2 −2
Original line number Diff line number Diff line
@@ -65,7 +65,7 @@ struct pnfs_layoutdriver_type { 
};



struct pnfs_layout_hdr {

	unsigned long		plh_refcount;

	atomic_t		plh_refcount;

	struct list_head	plh_layouts;   /* other client layouts */

	struct list_head	plh_segs;      /* layout segments list */

	nfs4_stateid		plh_stateid;
@@ -147,7 +147,7 @@ void unset_pnfs_layoutdriver(struct nfs_server *); 
int pnfs_layout_process(struct nfs4_layoutget *lgp);

void pnfs_destroy_layout(struct nfs_inode *);

void pnfs_destroy_all_layouts(struct nfs_client *);

void put_layout_hdr(struct inode *inode);

void put_layout_hdr(struct pnfs_layout_hdr *lo);

int pnfs_choose_layoutget_stateid(nfs4_stateid *dst,

				  struct pnfs_layout_hdr *lo,

				  struct nfs4_state *open_state);