patch-2.4.27 linux-2.4.27/fs/xfs/linux-2.4/xfs_vnode.c

• Lines: 467
• Date: 2004-08-07 16:26:06.099406153 -0700
• Orig file: linux-2.4.26/fs/xfs/linux-2.4/xfs_vnode.c
• Orig date: 1969-12-31 16:00:00.000000000 -0800

diff -urN linux-2.4.26/fs/xfs/linux-2.4/xfs_vnode.c linux-2.4.27/fs/xfs/linux-2.4/xfs_vnode.c
@@ -0,0 +1,466 @@
+/*
+ * Copyright (c) 2000-2003 Silicon Graphics, Inc.  All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it would be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * Further, this software is distributed without any warranty that it is
+ * free of the rightful claim of any third person regarding infringement
+ * or the like.  Any license provided herein, whether implied or
+ * otherwise, applies only to this software file.  Patent licenses, if
+ * any, provided herein do not apply to combinations of this program with
+ * other software, or any other product whatsoever.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write the Free Software Foundation, Inc., 59
+ * Temple Place - Suite 330, Boston MA 02111-1307, USA.
+ *
+ * Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy,
+ * Mountain View, CA  94043, or:
+ *
+ * http://www.sgi.com
+ *
+ * For further information regarding this notice, see:
+ *
+ * http://oss.sgi.com/projects/GenInfo/SGIGPLNoticeExplan/
+ */
+
+#include "xfs.h"
+
+
+uint64_t vn_generation;		/* vnode generation number */
+spinlock_t vnumber_lock = SPIN_LOCK_UNLOCKED;
+
+/*
+ * Dedicated vnode inactive/reclaim sync semaphores.
+ * Prime number of hash buckets since address is used as the key.
+ */
+#define NVSYNC                  37
+#define vptosync(v)             (&vsync[((unsigned long)v) % NVSYNC])
+sv_t vsync[NVSYNC];
+
+/*
+ * Translate stat(2) file types to vnode types and vice versa.
+ * Aware of numeric order of S_IFMT and vnode type values.
+ */
+enum vtype iftovt_tab[] = {
+	VNON, VFIFO, VCHR, VNON, VDIR, VNON, VBLK, VNON,
+	VREG, VNON, VLNK, VNON, VSOCK, VNON, VNON, VNON
+};
+
+u_short vttoif_tab[] = {
+	0, S_IFREG, S_IFDIR, S_IFBLK, S_IFCHR, S_IFLNK, S_IFIFO, 0, S_IFSOCK
+};
+
+
+void
+vn_init(void)
+{
+	register sv_t *svp;
+	register int i;
+
+	for (svp = vsync, i = 0; i < NVSYNC; i++, svp++)
+		init_sv(svp, SV_DEFAULT, "vsy", i);
+}
+
+/*
+ * Clean a vnode of filesystem-specific data and prepare it for reuse.
+ */
+STATIC int
+vn_reclaim(
+	struct vnode	*vp)
+{
+	int		error;
+
+	XFS_STATS_INC(vn_reclaim);
+	vn_trace_entry(vp, "vn_reclaim", (inst_t *)__return_address);
+
+	/*
+	 * Only make the VOP_RECLAIM call if there are behaviors
+	 * to call.
+	 */
+	if (vp->v_fbhv) {
+		VOP_RECLAIM(vp, error);
+		if (error)
+			return -error;
+	}
+	ASSERT(vp->v_fbhv == NULL);
+
+	VN_LOCK(vp);
+	vp->v_flag &= (VRECLM|VWAIT);
+	VN_UNLOCK(vp, 0);
+
+	vp->v_type = VNON;
+	vp->v_fbhv = NULL;
+
+#ifdef XFS_VNODE_TRACE
+	ktrace_free(vp->v_trace);
+	vp->v_trace = NULL;
+#endif
+
+	return 0;
+}
+
+STATIC void
+vn_wakeup(
+	struct vnode	*vp)
+{
+	VN_LOCK(vp);
+	if (vp->v_flag & VWAIT)
+		sv_broadcast(vptosync(vp));
+	vp->v_flag &= ~(VRECLM|VWAIT|VMODIFIED);
+	VN_UNLOCK(vp, 0);
+}
+
+int
+vn_wait(
+	struct vnode	*vp)
+{
+	VN_LOCK(vp);
+	if (vp->v_flag & (VINACT | VRECLM)) {
+		vp->v_flag |= VWAIT;
+		sv_wait(vptosync(vp), PINOD, &vp->v_lock, 0);
+		return 1;
+	}
+	VN_UNLOCK(vp, 0);
+	return 0;
+}
+
+struct vnode *
+vn_initialize(
+	struct inode	*inode)
+{
+	struct vnode	*vp = LINVFS_GET_VP(inode);
+
+	XFS_STATS_INC(vn_active);
+	XFS_STATS_INC(vn_alloc);
+
+	vp->v_flag = VMODIFIED;
+	spinlock_init(&vp->v_lock, "v_lock");
+
+	spin_lock(&vnumber_lock);
+	if (!++vn_generation)	/* v_number shouldn't be zero */
+		vn_generation++;
+	vp->v_number = vn_generation;
+	spin_unlock(&vnumber_lock);
+
+	ASSERT(VN_CACHED(vp) == 0);
+
+	/* Initialize the first behavior and the behavior chain head. */
+	vn_bhv_head_init(VN_BHV_HEAD(vp), "vnode");
+
+#ifdef	XFS_VNODE_TRACE
+	vp->v_trace = ktrace_alloc(VNODE_TRACE_SIZE, KM_SLEEP);
+	printk("Allocated VNODE_TRACE at 0x%p\n", vp->v_trace);
+#endif	/* XFS_VNODE_TRACE */
+
+	vn_trace_exit(vp, "vn_initialize", (inst_t *)__return_address);
+	return vp;
+}
+
+/*
+ * Get a reference on a vnode.
+ */
+vnode_t *
+vn_get(
+	struct vnode	*vp,
+	vmap_t		*vmap)
+{
+	struct inode	*inode;
+
+	XFS_STATS_INC(vn_get);
+	inode = LINVFS_GET_IP(vp);
+	if (inode->i_state & I_FREEING)
+		return NULL;
+
+	inode = VFS_GET_INODE(vmap->v_vfsp, vmap->v_ino, IGET_NOALLOC);
+	if (!inode)	/* Inode not present */
+		return NULL;
+
+	/* We do not want to create new inodes via vn_get,
+	 * returning NULL here is OK.
+	 */
+	if (inode->i_state & I_NEW) {
+		remove_inode_hash(inode);
+		make_bad_inode(inode);
+		unlock_new_inode(inode);
+		iput(inode);
+		return NULL;
+	}
+
+	vn_trace_exit(vp, "vn_get", (inst_t *)__return_address);
+
+	return vp;
+}
+
+/*
+ * Revalidate the Linux inode from the vattr.
+ * Note: i_size _not_ updated; we must hold the inode
+ * semaphore when doing that - callers responsibility.
+ */
+void
+vn_revalidate_core(
+	struct vnode	*vp,
+	vattr_t		*vap)
+{
+	struct inode	*inode = LINVFS_GET_IP(vp);
+
+	inode->i_mode	    = VTTOIF(vap->va_type) | vap->va_mode;
+	inode->i_nlink	    = vap->va_nlink;
+	inode->i_uid	    = vap->va_uid;
+	inode->i_gid	    = vap->va_gid;
+	inode->i_blocks	    = vap->va_nblocks;
+	inode->i_mtime	    = vap->va_mtime.tv_sec;
+	inode->i_ctime	    = vap->va_ctime.tv_sec;
+	inode->i_atime	    = vap->va_atime.tv_sec;
+	if (vap->va_xflags & XFS_XFLAG_IMMUTABLE)
+		inode->i_flags |= S_IMMUTABLE;
+	else
+		inode->i_flags &= ~S_IMMUTABLE;
+	if (vap->va_xflags & XFS_XFLAG_APPEND)
+		inode->i_flags |= S_APPEND;
+	else
+		inode->i_flags &= ~S_APPEND;
+	if (vap->va_xflags & XFS_XFLAG_SYNC)
+		inode->i_flags |= S_SYNC;
+	else
+		inode->i_flags &= ~S_SYNC;
+	if (vap->va_xflags & XFS_XFLAG_NOATIME)
+		inode->i_flags |= S_NOATIME;
+	else
+		inode->i_flags &= ~S_NOATIME;
+}
+
+/*
+ * Revalidate the Linux inode from the vnode.
+ */
+int
+vn_revalidate(
+	struct vnode	*vp)
+{
+	vattr_t		va;
+	int		error;
+
+	vn_trace_entry(vp, "vn_revalidate", (inst_t *)__return_address);
+	ASSERT(vp->v_fbhv != NULL);
+
+	va.va_mask = XFS_AT_STAT|XFS_AT_XFLAGS;
+	VOP_GETATTR(vp, &va, 0, NULL, error);
+	if (!error) {
+		vn_revalidate_core(vp, &va);
+		VUNMODIFY(vp);
+	}
+	return -error;
+}
+
+/*
+ * purge a vnode from the cache
+ * At this point the vnode is guaranteed to have no references (vn_count == 0)
+ * The caller has to make sure that there are no ways someone could
+ * get a handle (via vn_get) on the vnode (usually done via a mount/vfs lock).
+ */
+void
+vn_purge(
+	struct vnode	*vp,
+	vmap_t		*vmap)
+{
+	vn_trace_entry(vp, "vn_purge", (inst_t *)__return_address);
+
+again:
+	/*
+	 * Check whether vp has already been reclaimed since our caller
+	 * sampled its version while holding a filesystem cache lock that
+	 * its VOP_RECLAIM function acquires.
+	 */
+	VN_LOCK(vp);
+	if (vp->v_number != vmap->v_number) {
+		VN_UNLOCK(vp, 0);
+		return;
+	}
+
+	/*
+	 * If vp is being reclaimed or inactivated, wait until it is inert,
+	 * then proceed.  Can't assume that vnode is actually reclaimed
+	 * just because the reclaimed flag is asserted -- a vn_alloc
+	 * reclaim can fail.
+	 */
+	if (vp->v_flag & (VINACT | VRECLM)) {
+		ASSERT(vn_count(vp) == 0);
+		vp->v_flag |= VWAIT;
+		sv_wait(vptosync(vp), PINOD, &vp->v_lock, 0);
+		goto again;
+	}
+
+	/*
+	 * Another process could have raced in and gotten this vnode...
+	 */
+	if (vn_count(vp) > 0) {
+		VN_UNLOCK(vp, 0);
+		return;
+	}
+
+	XFS_STATS_DEC(vn_active);
+	vp->v_flag |= VRECLM;
+	VN_UNLOCK(vp, 0);
+
+	/*
+	 * Call VOP_RECLAIM and clean vp. The FSYNC_INVAL flag tells
+	 * vp's filesystem to flush and invalidate all cached resources.
+	 * When vn_reclaim returns, vp should have no private data,
+	 * either in a system cache or attached to v_data.
+	 */
+	if (vn_reclaim(vp) != 0)
+		panic("vn_purge: cannot reclaim");
+
+	/*
+	 * Wakeup anyone waiting for vp to be reclaimed.
+	 */
+	vn_wakeup(vp);
+}
+
+/*
+ * Add a reference to a referenced vnode.
+ */
+struct vnode *
+vn_hold(
+	struct vnode	*vp)
+{
+	struct inode	*inode;
+
+	XFS_STATS_INC(vn_hold);
+
+	VN_LOCK(vp);
+	inode = igrab(LINVFS_GET_IP(vp));
+	ASSERT(inode);
+	VN_UNLOCK(vp, 0);
+
+	return vp;
+}
+
+/*
+ *  Call VOP_INACTIVE on last reference.
+ */
+void
+vn_rele(
+	struct vnode	*vp)
+{
+	int		vcnt;
+	int		cache;
+
+	XFS_STATS_INC(vn_rele);
+
+	VN_LOCK(vp);
+
+	vn_trace_entry(vp, "vn_rele", (inst_t *)__return_address);
+	vcnt = vn_count(vp);
+
+	/*
+	 * Since we always get called from put_inode we know
+	 * that i_count won't be decremented after we
+	 * return.
+	 */
+	if (!vcnt) {
+		/*
+		 * As soon as we turn this on, noone can find us in vn_get
+		 * until we turn off VINACT or VRECLM
+		 */
+		vp->v_flag |= VINACT;
+		VN_UNLOCK(vp, 0);
+
+		/*
+		 * Do not make the VOP_INACTIVE call if there
+		 * are no behaviors attached to the vnode to call.
+		 */
+		if (vp->v_fbhv)
+			VOP_INACTIVE(vp, NULL, cache);
+
+		VN_LOCK(vp);
+		if (vp->v_flag & VWAIT)
+			sv_broadcast(vptosync(vp));
+
+		vp->v_flag &= ~(VINACT|VWAIT|VRECLM|VMODIFIED);
+	}
+
+	VN_UNLOCK(vp, 0);
+
+	vn_trace_exit(vp, "vn_rele", (inst_t *)__return_address);
+}
+
+/*
+ * Finish the removal of a vnode.
+ */
+void
+vn_remove(
+	struct vnode	*vp)
+{
+	vmap_t		vmap;
+
+	/* Make sure we don't do this to the same vnode twice */
+	if (!(vp->v_fbhv))
+		return;
+
+	XFS_STATS_INC(vn_remove);
+	vn_trace_exit(vp, "vn_remove", (inst_t *)__return_address);
+
+	/*
+	 * After the following purge the vnode
+	 * will no longer exist.
+	 */
+	VMAP(vp, vmap);
+	vn_purge(vp, &vmap);
+}
+
+
+#ifdef	XFS_VNODE_TRACE
+
+#define KTRACE_ENTER(vp, vk, s, line, ra)			\
+	ktrace_enter(	(vp)->v_trace,				\
+/*  0 */		(void *)(__psint_t)(vk),		\
+/*  1 */		(void *)(s),				\
+/*  2 */		(void *)(__psint_t) line,		\
+/*  3 */		(void *)(vn_count(vp)), \
+/*  4 */		(void *)(ra),				\
+/*  5 */		(void *)(__psunsigned_t)(vp)->v_flag,	\
+/*  6 */		(void *)(__psint_t)smp_processor_id(),	\
+/*  7 */		(void *)(__psint_t)(current->pid),	\
+/*  8 */		(void *)__return_address,		\
+/*  9 */		0, 0, 0, 0, 0, 0, 0)
+
+/*
+ * Vnode tracing code.
+ */
+void
+vn_trace_entry(vnode_t *vp, char *func, inst_t *ra)
+{
+	KTRACE_ENTER(vp, VNODE_KTRACE_ENTRY, func, 0, ra);
+}
+
+void
+vn_trace_exit(vnode_t *vp, char *func, inst_t *ra)
+{
+	KTRACE_ENTER(vp, VNODE_KTRACE_EXIT, func, 0, ra);
+}
+
+void
+vn_trace_hold(vnode_t *vp, char *file, int line, inst_t *ra)
+{
+	KTRACE_ENTER(vp, VNODE_KTRACE_HOLD, file, line, ra);
+}
+
+void
+vn_trace_ref(vnode_t *vp, char *file, int line, inst_t *ra)
+{
+	KTRACE_ENTER(vp, VNODE_KTRACE_REF, file, line, ra);
+}
+
+void
+vn_trace_rele(vnode_t *vp, char *file, int line, inst_t *ra)
+{
+	KTRACE_ENTER(vp, VNODE_KTRACE_RELE, file, line, ra);
+}
+#endif	/* XFS_VNODE_TRACE */