fs: don't use igrab() while holding i_lock (0444d76a) · Commits · 戴 / test

Fix the incorrect use of igrab() inside the i_lock in NFS and Ceph‥ If we are already holding the i_lock, we have a reference to the inode so we can safely use ihold() to gain an extra reference. This avoids hangs due to lock recursion on the i_lock now that the inode_lock is gone and igrab() uses the i_lock itself. Signed-off-by:

Dave Chinner <dchinner@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: linux-fsdevel@vger.kernel.org Cc: Ryan Mallon <ryan@bluewatersys.com> Signed-off-by:

Linus Torvalds <torvalds@linux-foundation.org>

fs/ceph/addr.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -92,7 +92,7 @@ static int ceph_set_page_dirty(struct page *page)
		ci->i_head_snapc = ceph_get_snap_context(snapc);
		++ci->i_wrbuffer_ref_head;
		if (ci->i_wrbuffer_ref == 0)
		igrab(inode);
		ihold(inode);
		++ci->i_wrbuffer_ref;
		dout("%p set_page_dirty %p idx %lu head %d/%d -> %d/%d "
		"snapc %p seq %lld (%d snaps)\n",

fs/ceph/snap.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -463,7 +463,7 @@ void ceph_queue_cap_snap(struct ceph_inode_info *ci)

		dout("queue_cap_snap %p cap_snap %p queuing under %p\n", inode,
		capsnap, snapc);
		igrab(inode);
		ihold(inode);

		atomic_set(&capsnap->nref, 1);
		capsnap->ci = ci;

fs/nfs/nfs4state.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -590,7 +590,8 @@ nfs4_get_open_state(struct inode inode, struct nfs4_state_owner owner)
		state->owner = owner;
		atomic_inc(&owner->so_count);
		list_add(&state->inode_states, &nfsi->open_states);
		state->inode = igrab(inode);
		ihold(inode);
		state->inode = inode;
		spin_unlock(&inode->i_lock);
		/* Note: The reclaim code dictates that we add stateless
		* and read-only stateids to the end of the list */

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