[PATCH 11/11] nfs: use wait_var_event_spinlock() to wait for nfsi->layout to change.
From: NeilBrown <hidden>
Date: 2024-12-06 02:20:14
Subsystem:
filesystems (vfs and infrastructure), nfs, sunrpc, and lockd clients, the rest · Maintainers:
Alexander Viro, Christian Brauner, Trond Myklebust, Anna Schumaker, Linus Torvalds
The recently added interface wait_var_event_spinlock() is designed for waiting for events that can only be checked under a spinlock. This matches the requirements for waiting for nfsi->layout so we can change to using wait_var_event_spinlock(). This avoids a use of plain wake_up_var() which always needs to be checked for correct barrier usage. Signed-off-by: NeilBrown <redacted> --- fs/nfs/pnfs.c | 27 +++++++++------------------ 1 file changed, 9 insertions(+), 18 deletions(-)
diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index 400f409f45fa..04be1165a1c5 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c@@ -306,7 +306,6 @@ void pnfs_put_layout_hdr(struct pnfs_layout_hdr *lo) { struct inode *inode; - unsigned long i_state; if (!lo) return;
@@ -317,12 +316,11 @@ pnfs_put_layout_hdr(struct pnfs_layout_hdr *lo) if (!list_empty(&lo->plh_segs)) WARN_ONCE(1, "NFS: BUG unfreed layout segments.\n"); pnfs_detach_layout_hdr(lo); - i_state = inode->i_state; + /* Notify pnfs_destroy_layout_final() that we're done */ + if (inode->i_state & (I_FREEING | I_CLEAR)) + wake_up_var_locked(lo, &inode->i_lock); spin_unlock(&inode->i_lock); pnfs_free_layout_hdr(lo); - /* Notify pnfs_destroy_layout_final() that we're done */ - if (i_state & (I_FREEING | I_CLEAR)) - wake_up_var(lo); } }
@@ -795,23 +793,16 @@ void pnfs_destroy_layout(struct nfs_inode *nfsi) } EXPORT_SYMBOL_GPL(pnfs_destroy_layout); -static bool pnfs_layout_removed(struct nfs_inode *nfsi, - struct pnfs_layout_hdr *lo) -{ - bool ret; - - spin_lock(&nfsi->vfs_inode.i_lock); - ret = nfsi->layout != lo; - spin_unlock(&nfsi->vfs_inode.i_lock); - return ret; -} - void pnfs_destroy_layout_final(struct nfs_inode *nfsi) { struct pnfs_layout_hdr *lo = __pnfs_destroy_layout(nfsi); - if (lo) - wait_var_event(lo, pnfs_layout_removed(nfsi, lo)); + if (lo) { + spin_lock(&nfsi->vfs_inode.i_lock); + wait_var_event_spinlock(lo, nfsi->layout != lo, + &nfsi->vfs_inode.i_lock); + spin_unlock(&nfsi->vfs_inode.i_lock); + } } static bool
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2.47.0