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kernel_samsung_sm7125/fs/xfs/linux-2.6/xfs_vnode.c

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/*
* 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 */
DEFINE_SPINLOCK(vnumber_lock);
/*
* 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);
#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 = ilookup(vmap->v_vfsp->vfs_super, vmap->v_ino);
if (!inode) /* Inode not present */
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;
inode->i_ctime = vap->va_ctime;
inode->i_atime = vap->va_atime;
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)current_cpu(), \
/* 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, const char *func, inst_t *ra)
{
KTRACE_ENTER(vp, VNODE_KTRACE_ENTRY, func, 0, ra);
}
void
vn_trace_exit(vnode_t *vp, const 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 */