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Commit 4b09ec4b authored by Benjamin Coddington's avatar Benjamin Coddington Committed by Trond Myklebust
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nfs: Don't take a reference on fl->fl_file for LOCK operation 



I have reports of a crash that look like __fput() was called twice for
a NFSv4.0 file.  It seems possible that the state manager could try to
reclaim a lock and take a reference on the fl->fl_file at the same time the
file is being released if, during the close(), a signal interrupts the wait
for outstanding IO while removing locks which then skips the removal
of that lock.

Since 83bfff23 ("nfs4: have do_vfs_lock take an inode pointer") has
removed the need to traverse fl->fl_file->f_inode in nfs4_lock_done(),
taking that reference is no longer necessary.

Signed-off-by: default avatarBenjamin Coddington <bcodding@redhat.com>
Reviewed-by: default avatarJeff Layton <jlayton@redhat.com>
Signed-off-by: default avatarTrond Myklebust <trond.myklebust@primarydata.com>
parent a121103c

fs/nfs/nfs4proc.c

+0 −3
Original line number Diff line number Diff line
@@ -38,7 +38,6 @@ 
#include <linux/mm.h>

#include <linux/delay.h>

#include <linux/errno.h>

#include <linux/file.h>

#include <linux/string.h>

#include <linux/ratelimit.h>

#include <linux/printk.h>
@@ -6127,7 +6126,6 @@ static struct nfs4_lockdata *nfs4_alloc_lockdata(struct file_lock *fl, 
	p->server = server;

	atomic_inc(&lsp->ls_count);

	p->ctx = get_nfs_open_context(ctx);

	get_file(fl->fl_file);

	memcpy(&p->fl, fl, sizeof(p->fl));

	return p;

out_free_seqid:
@@ -6240,7 +6238,6 @@ static void nfs4_lock_release(void *calldata) 
		nfs_free_seqid(data->arg.lock_seqid);

	nfs4_put_lock_state(data->lsp);

	put_nfs_open_context(data->ctx);

	fput(data->fl.fl_file);

	kfree(data);

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

}