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linux/fs/xfs/xfs_iget.c

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/*
* Copyright (c) 2000-2005 Silicon Graphics, Inc.
* All Rights Reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms 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. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "xfs.h"
#include "xfs_fs.h"
#include "xfs_types.h"
#include "xfs_bit.h"
#include "xfs_log.h"
#include "xfs_inum.h"
#include "xfs_trans.h"
#include "xfs_sb.h"
#include "xfs_ag.h"
#include "xfs_dir2.h"
#include "xfs_dmapi.h"
#include "xfs_mount.h"
#include "xfs_bmap_btree.h"
#include "xfs_alloc_btree.h"
#include "xfs_ialloc_btree.h"
#include "xfs_dir2_sf.h"
#include "xfs_attr_sf.h"
#include "xfs_dinode.h"
#include "xfs_inode.h"
#include "xfs_btree.h"
#include "xfs_ialloc.h"
#include "xfs_quota.h"
#include "xfs_utils.h"
/*
* Look up an inode by number in the given file system.
* The inode is looked up in the cache held in each AG.
* If the inode is found in the cache, attach it to the provided
* vnode.
*
* If it is not in core, read it in from the file system's device,
* add it to the cache and attach the provided vnode.
*
* The inode is locked according to the value of the lock_flags parameter.
* This flag parameter indicates how and if the inode's IO lock and inode lock
* should be taken.
*
* mp -- the mount point structure for the current file system. It points
* to the inode hash table.
* tp -- a pointer to the current transaction if there is one. This is
* simply passed through to the xfs_iread() call.
* ino -- the number of the inode desired. This is the unique identifier
* within the file system for the inode being requested.
* lock_flags -- flags indicating how to lock the inode. See the comment
* for xfs_ilock() for a list of valid values.
* bno -- the block number starting the buffer containing the inode,
* if known (as by bulkstat), else 0.
*/
STATIC int
xfs_iget_core(
bhv_vnode_t *vp,
xfs_mount_t *mp,
xfs_trans_t *tp,
xfs_ino_t ino,
uint flags,
uint lock_flags,
xfs_inode_t **ipp,
xfs_daddr_t bno)
{
xfs_inode_t *ip;
xfs_inode_t *iq;
bhv_vnode_t *inode_vp;
int error;
xfs_icluster_t *icl, *new_icl = NULL;
unsigned long first_index, mask;
xfs_perag_t *pag;
xfs_agino_t agino;
/* the radix tree exists only in inode capable AGs */
if (XFS_INO_TO_AGNO(mp, ino) >= mp->m_maxagi)
return EINVAL;
/* get the perag structure and ensure that it's inode capable */
pag = xfs_get_perag(mp, ino);
if (!pag->pagi_inodeok)
return EINVAL;
ASSERT(pag->pag_ici_init);
agino = XFS_INO_TO_AGINO(mp, ino);
again:
read_lock(&pag->pag_ici_lock);
ip = radix_tree_lookup(&pag->pag_ici_root, agino);
if (ip != NULL) {
/*
* If INEW is set this inode is being set up
* we need to pause and try again.
*/
if (xfs_iflags_test(ip, XFS_INEW)) {
read_unlock(&pag->pag_ici_lock);
delay(1);
XFS_STATS_INC(xs_ig_frecycle);
goto again;
}
inode_vp = XFS_ITOV_NULL(ip);
if (inode_vp == NULL) {
/*
* If IRECLAIM is set this inode is
* on its way out of the system,
* we need to pause and try again.
*/
if (xfs_iflags_test(ip, XFS_IRECLAIM)) {
read_unlock(&pag->pag_ici_lock);
delay(1);
XFS_STATS_INC(xs_ig_frecycle);
goto again;
}
ASSERT(xfs_iflags_test(ip, XFS_IRECLAIMABLE));
/*
* If lookup is racing with unlink, then we
* should return an error immediately so we
* don't remove it from the reclaim list and
* potentially leak the inode.
*/
if ((ip->i_d.di_mode == 0) &&
!(flags & XFS_IGET_CREATE)) {
read_unlock(&pag->pag_ici_lock);
xfs_put_perag(mp, pag);
return ENOENT;
}
/*
* There may be transactions sitting in the
* incore log buffers or being flushed to disk
* at this time. We can't clear the
* XFS_IRECLAIMABLE flag until these
* transactions have hit the disk, otherwise we
* will void the guarantee the flag provides
* xfs_iunpin()
*/
if (xfs_ipincount(ip)) {
read_unlock(&pag->pag_ici_lock);
xfs_log_force(mp, 0,
XFS_LOG_FORCE|XFS_LOG_SYNC);
XFS_STATS_INC(xs_ig_frecycle);
goto again;
}
vn_trace_exit(ip, "xfs_iget.alloc",
(inst_t *)__return_address);
XFS_STATS_INC(xs_ig_found);
xfs_iflags_clear(ip, XFS_IRECLAIMABLE);
read_unlock(&pag->pag_ici_lock);
XFS_MOUNT_ILOCK(mp);
list_del_init(&ip->i_reclaim);
XFS_MOUNT_IUNLOCK(mp);
goto finish_inode;
} else if (vp != inode_vp) {
struct inode *inode = vn_to_inode(inode_vp);
/* The inode is being torn down, pause and
* try again.
*/
if (inode->i_state & (I_FREEING | I_CLEAR)) {
read_unlock(&pag->pag_ici_lock);
delay(1);
XFS_STATS_INC(xs_ig_frecycle);
goto again;
}
/* Chances are the other vnode (the one in the inode) is being torn
* down right now, and we landed on top of it. Question is, what do
* we do? Unhook the old inode and hook up the new one?
*/
cmn_err(CE_PANIC,
"xfs_iget_core: ambiguous vns: vp/0x%p, invp/0x%p",
inode_vp, vp);
}
/*
* Inode cache hit
*/
read_unlock(&pag->pag_ici_lock);
XFS_STATS_INC(xs_ig_found);
finish_inode:
if (ip->i_d.di_mode == 0) {
if (!(flags & XFS_IGET_CREATE)) {
xfs_put_perag(mp, pag);
return ENOENT;
}
xfs_iocore_inode_reinit(ip);
}
if (lock_flags != 0)
xfs_ilock(ip, lock_flags);
xfs_iflags_clear(ip, XFS_ISTALE);
vn_trace_exit(ip, "xfs_iget.found",
(inst_t *)__return_address);
goto return_ip;
}
/*
* Inode cache miss
*/
read_unlock(&pag->pag_ici_lock);
XFS_STATS_INC(xs_ig_missed);
/*
* Read the disk inode attributes into a new inode structure and get
* a new vnode for it. This should also initialize i_ino and i_mount.
*/
error = xfs_iread(mp, tp, ino, &ip, bno,
(flags & XFS_IGET_BULKSTAT) ? XFS_IMAP_BULKSTAT : 0);
if (error) {
xfs_put_perag(mp, pag);
return error;
}
vn_trace_exit(ip, "xfs_iget.alloc", (inst_t *)__return_address);
xfs_inode_lock_init(ip, vp);
xfs_iocore_inode_init(ip);
if (lock_flags)
xfs_ilock(ip, lock_flags);
if ((ip->i_d.di_mode == 0) && !(flags & XFS_IGET_CREATE)) {
xfs_idestroy(ip);
xfs_put_perag(mp, pag);
return ENOENT;
}
/*
* This is a bit messy - we preallocate everything we _might_
* need before we pick up the ici lock. That way we don't have to
* juggle locks and go all the way back to the start.
*/
new_icl = kmem_zone_alloc(xfs_icluster_zone, KM_SLEEP);
if (radix_tree_preload(GFP_KERNEL)) {
delay(1);
goto again;
}
mask = ~(((XFS_INODE_CLUSTER_SIZE(mp) >> mp->m_sb.sb_inodelog)) - 1);
first_index = agino & mask;
write_lock(&pag->pag_ici_lock);
/*
* Find the cluster if it exists
*/
icl = NULL;
if (radix_tree_gang_lookup(&pag->pag_ici_root, (void**)&iq,
first_index, 1)) {
if ((iq->i_ino & mask) == first_index)
icl = iq->i_cluster;
}
/*
* insert the new inode
*/
error = radix_tree_insert(&pag->pag_ici_root, agino, ip);
if (unlikely(error)) {
BUG_ON(error != -EEXIST);
write_unlock(&pag->pag_ici_lock);
radix_tree_preload_end();
xfs_idestroy(ip);
XFS_STATS_INC(xs_ig_dup);
goto again;
}
/*
* These values _must_ be set before releasing ihlock!
*/
ip->i_udquot = ip->i_gdquot = NULL;
xfs_iflags_set(ip, XFS_INEW);
ASSERT(ip->i_cluster == NULL);
if (!icl) {
spin_lock_init(&new_icl->icl_lock);
INIT_HLIST_HEAD(&new_icl->icl_inodes);
icl = new_icl;
new_icl = NULL;
} else {
ASSERT(!hlist_empty(&icl->icl_inodes));
}
spin_lock(&icl->icl_lock);
hlist_add_head(&ip->i_cnode, &icl->icl_inodes);
ip->i_cluster = icl;
spin_unlock(&icl->icl_lock);
write_unlock(&pag->pag_ici_lock);
radix_tree_preload_end();
if (new_icl)
kmem_zone_free(xfs_icluster_zone, new_icl);
/*
* Link ip to its mount and thread it on the mount's inode list.
*/
XFS_MOUNT_ILOCK(mp);
if ((iq = mp->m_inodes)) {
ASSERT(iq->i_mprev->i_mnext == iq);
ip->i_mprev = iq->i_mprev;
iq->i_mprev->i_mnext = ip;
iq->i_mprev = ip;
ip->i_mnext = iq;
} else {
ip->i_mnext = ip;
ip->i_mprev = ip;
}
mp->m_inodes = ip;
XFS_MOUNT_IUNLOCK(mp);
xfs_put_perag(mp, pag);
return_ip:
ASSERT(ip->i_df.if_ext_max ==
XFS_IFORK_DSIZE(ip) / sizeof(xfs_bmbt_rec_t));
ASSERT(((ip->i_d.di_flags & XFS_DIFLAG_REALTIME) != 0) ==
((ip->i_iocore.io_flags & XFS_IOCORE_RT) != 0));
xfs_iflags_set(ip, XFS_IMODIFIED);
*ipp = ip;
/*
* If we have a real type for an on-disk inode, we can set ops(&unlock)
* now. If it's a new inode being created, xfs_ialloc will handle it.
*/
xfs_initialize_vnode(mp, vp, ip);
return 0;
}
/*
* The 'normal' internal xfs_iget, if needed it will
* 'allocate', or 'get', the vnode.
*/
int
xfs_iget(
xfs_mount_t *mp,
xfs_trans_t *tp,
xfs_ino_t ino,
uint flags,
uint lock_flags,
xfs_inode_t **ipp,
xfs_daddr_t bno)
{
struct inode *inode;
bhv_vnode_t *vp = NULL;
int error;
XFS_STATS_INC(xs_ig_attempts);
retry:
inode = iget_locked(mp->m_super, ino);
if (inode) {
xfs_inode_t *ip;
vp = vn_from_inode(inode);
if (inode->i_state & I_NEW) {
vn_initialize(inode);
error = xfs_iget_core(vp, mp, tp, ino, flags,
lock_flags, ipp, bno);
if (error) {
vn_mark_bad(vp);
if (inode->i_state & I_NEW)
unlock_new_inode(inode);
iput(inode);
}
} else {
/*
* If the inode is not fully constructed due to
* filehandle mismatches wait for the inode to go
* away and try again.
*
* iget_locked will call __wait_on_freeing_inode
* to wait for the inode to go away.
*/
if (is_bad_inode(inode) ||
((ip = xfs_vtoi(vp)) == NULL)) {
iput(inode);
delay(1);
goto retry;
}
if (lock_flags != 0)
xfs_ilock(ip, lock_flags);
XFS_STATS_INC(xs_ig_found);
*ipp = ip;
error = 0;
}
} else
error = ENOMEM; /* If we got no inode we are out of memory */
return error;
}
/*
* Do the setup for the various locks within the incore inode.
*/
void
xfs_inode_lock_init(
xfs_inode_t *ip,
bhv_vnode_t *vp)
{
mrlock_init(&ip->i_lock, MRLOCK_ALLOW_EQUAL_PRI|MRLOCK_BARRIER,
"xfsino", ip->i_ino);
mrlock_init(&ip->i_iolock, MRLOCK_BARRIER, "xfsio", ip->i_ino);
init_waitqueue_head(&ip->i_ipin_wait);
atomic_set(&ip->i_pincount, 0);
initnsema(&ip->i_flock, 1, "xfsfino");
}
/*
* Look for the inode corresponding to the given ino in the hash table.
* If it is there and its i_transp pointer matches tp, return it.
* Otherwise, return NULL.
*/
xfs_inode_t *
xfs_inode_incore(xfs_mount_t *mp,
xfs_ino_t ino,
xfs_trans_t *tp)
{
xfs_inode_t *ip;
xfs_perag_t *pag;
pag = xfs_get_perag(mp, ino);
read_lock(&pag->pag_ici_lock);
ip = radix_tree_lookup(&pag->pag_ici_root, XFS_INO_TO_AGINO(mp, ino));
read_unlock(&pag->pag_ici_lock);
xfs_put_perag(mp, pag);
/* the returned inode must match the transaction */
if (ip && (ip->i_transp != tp))
return NULL;
return ip;
}
/*
* Decrement reference count of an inode structure and unlock it.
*
* ip -- the inode being released
* lock_flags -- this parameter indicates the inode's locks to be
* to be released. See the comment on xfs_iunlock() for a list
* of valid values.
*/
void
xfs_iput(xfs_inode_t *ip,
uint lock_flags)
{
bhv_vnode_t *vp = XFS_ITOV(ip);
vn_trace_entry(ip, "xfs_iput", (inst_t *)__return_address);
xfs_iunlock(ip, lock_flags);
VN_RELE(vp);
}
/*
* Special iput for brand-new inodes that are still locked
*/
void
xfs_iput_new(xfs_inode_t *ip,
uint lock_flags)
{
bhv_vnode_t *vp = XFS_ITOV(ip);
struct inode *inode = vn_to_inode(vp);
vn_trace_entry(ip, "xfs_iput_new", (inst_t *)__return_address);
if ((ip->i_d.di_mode == 0)) {
ASSERT(!xfs_iflags_test(ip, XFS_IRECLAIMABLE));
vn_mark_bad(vp);
}
if (inode->i_state & I_NEW)
unlock_new_inode(inode);
if (lock_flags)
xfs_iunlock(ip, lock_flags);
VN_RELE(vp);
}
/*
* This routine embodies the part of the reclaim code that pulls
* the inode from the inode hash table and the mount structure's
* inode list.
* This should only be called from xfs_reclaim().
*/
void
xfs_ireclaim(xfs_inode_t *ip)
{
bhv_vnode_t *vp;
/*
* Remove from old hash list and mount list.
*/
XFS_STATS_INC(xs_ig_reclaims);
xfs_iextract(ip);
/*
* Here we do a spurious inode lock in order to coordinate with
* xfs_sync(). This is because xfs_sync() references the inodes
* in the mount list without taking references on the corresponding
* vnodes. We make that OK here by ensuring that we wait until
* the inode is unlocked in xfs_sync() before we go ahead and
* free it. We get both the regular lock and the io lock because
* the xfs_sync() code may need to drop the regular one but will
* still hold the io lock.
*/
xfs_ilock(ip, XFS_ILOCK_EXCL | XFS_IOLOCK_EXCL);
/*
* Release dquots (and their references) if any. An inode may escape
* xfs_inactive and get here via vn_alloc->vn_reclaim path.
*/
XFS_QM_DQDETACH(ip->i_mount, ip);
/*
* Pull our behavior descriptor from the vnode chain.
*/
vp = XFS_ITOV_NULL(ip);
if (vp) {
vn_to_inode(vp)->i_private = NULL;
ip->i_vnode = NULL;
}
/*
* Free all memory associated with the inode.
*/
xfs_iunlock(ip, XFS_ILOCK_EXCL | XFS_IOLOCK_EXCL);
xfs_idestroy(ip);
}
/*
* This routine removes an about-to-be-destroyed inode from
* all of the lists in which it is located with the exception
* of the behavior chain.
*/
void
xfs_iextract(
xfs_inode_t *ip)
{
xfs_mount_t *mp = ip->i_mount;
xfs_perag_t *pag = xfs_get_perag(mp, ip->i_ino);
xfs_inode_t *iq;
write_lock(&pag->pag_ici_lock);
radix_tree_delete(&pag->pag_ici_root, XFS_INO_TO_AGINO(mp, ip->i_ino));
write_unlock(&pag->pag_ici_lock);
xfs_put_perag(mp, pag);
/*
* Remove from cluster list
*/
mp = ip->i_mount;
spin_lock(&ip->i_cluster->icl_lock);
hlist_del(&ip->i_cnode);
spin_unlock(&ip->i_cluster->icl_lock);
/* was last inode in cluster? */
if (hlist_empty(&ip->i_cluster->icl_inodes))
kmem_zone_free(xfs_icluster_zone, ip->i_cluster);
/*
* Remove from mount's inode list.
*/
XFS_MOUNT_ILOCK(mp);
ASSERT((ip->i_mnext != NULL) && (ip->i_mprev != NULL));
iq = ip->i_mnext;
iq->i_mprev = ip->i_mprev;
ip->i_mprev->i_mnext = iq;
/*
* Fix up the head pointer if it points to the inode being deleted.
*/
if (mp->m_inodes == ip) {
if (ip == iq) {
mp->m_inodes = NULL;
} else {
mp->m_inodes = iq;
}
}
/* Deal with the deleted inodes list */
list_del_init(&ip->i_reclaim);
mp->m_ireclaims++;
XFS_MOUNT_IUNLOCK(mp);
}
/*
* This is a wrapper routine around the xfs_ilock() routine
* used to centralize some grungy code. It is used in places
* that wish to lock the inode solely for reading the extents.
* The reason these places can't just call xfs_ilock(SHARED)
* is that the inode lock also guards to bringing in of the
* extents from disk for a file in b-tree format. If the inode
* is in b-tree format, then we need to lock the inode exclusively
* until the extents are read in. Locking it exclusively all
* the time would limit our parallelism unnecessarily, though.
* What we do instead is check to see if the extents have been
* read in yet, and only lock the inode exclusively if they
* have not.
*
* The function returns a value which should be given to the
* corresponding xfs_iunlock_map_shared(). This value is
* the mode in which the lock was actually taken.
*/
uint
xfs_ilock_map_shared(
xfs_inode_t *ip)
{
uint lock_mode;
if ((ip->i_d.di_format == XFS_DINODE_FMT_BTREE) &&
((ip->i_df.if_flags & XFS_IFEXTENTS) == 0)) {
lock_mode = XFS_ILOCK_EXCL;
} else {
lock_mode = XFS_ILOCK_SHARED;
}
xfs_ilock(ip, lock_mode);
return lock_mode;
}
/*
* This is simply the unlock routine to go with xfs_ilock_map_shared().
* All it does is call xfs_iunlock() with the given lock_mode.
*/
void
xfs_iunlock_map_shared(
xfs_inode_t *ip,
unsigned int lock_mode)
{
xfs_iunlock(ip, lock_mode);
}
/*
* The xfs inode contains 2 locks: a multi-reader lock called the
* i_iolock and a multi-reader lock called the i_lock. This routine
* allows either or both of the locks to be obtained.
*
* The 2 locks should always be ordered so that the IO lock is
* obtained first in order to prevent deadlock.
*
* ip -- the inode being locked
* lock_flags -- this parameter indicates the inode's locks
* to be locked. It can be:
* XFS_IOLOCK_SHARED,
* XFS_IOLOCK_EXCL,
* XFS_ILOCK_SHARED,
* XFS_ILOCK_EXCL,
* XFS_IOLOCK_SHARED | XFS_ILOCK_SHARED,
* XFS_IOLOCK_SHARED | XFS_ILOCK_EXCL,
* XFS_IOLOCK_EXCL | XFS_ILOCK_SHARED,
* XFS_IOLOCK_EXCL | XFS_ILOCK_EXCL
*/
void
xfs_ilock(xfs_inode_t *ip,
uint lock_flags)
{
/*
* You can't set both SHARED and EXCL for the same lock,
* and only XFS_IOLOCK_SHARED, XFS_IOLOCK_EXCL, XFS_ILOCK_SHARED,
* and XFS_ILOCK_EXCL are valid values to set in lock_flags.
*/
ASSERT((lock_flags & (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL)) !=
(XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL));
ASSERT((lock_flags & (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL)) !=
(XFS_ILOCK_SHARED | XFS_ILOCK_EXCL));
ASSERT((lock_flags & ~(XFS_LOCK_MASK | XFS_LOCK_DEP_MASK)) == 0);
if (lock_flags & XFS_IOLOCK_EXCL) {
mrupdate_nested(&ip->i_iolock, XFS_IOLOCK_DEP(lock_flags));
} else if (lock_flags & XFS_IOLOCK_SHARED) {
mraccess_nested(&ip->i_iolock, XFS_IOLOCK_DEP(lock_flags));
}
if (lock_flags & XFS_ILOCK_EXCL) {
mrupdate_nested(&ip->i_lock, XFS_ILOCK_DEP(lock_flags));
} else if (lock_flags & XFS_ILOCK_SHARED) {
mraccess_nested(&ip->i_lock, XFS_ILOCK_DEP(lock_flags));
}
xfs_ilock_trace(ip, 1, lock_flags, (inst_t *)__return_address);
}
/*
* This is just like xfs_ilock(), except that the caller
* is guaranteed not to sleep. It returns 1 if it gets
* the requested locks and 0 otherwise. If the IO lock is
* obtained but the inode lock cannot be, then the IO lock
* is dropped before returning.
*
* ip -- the inode being locked
* lock_flags -- this parameter indicates the inode's locks to be
* to be locked. See the comment for xfs_ilock() for a list
* of valid values.
*
*/
int
xfs_ilock_nowait(xfs_inode_t *ip,
uint lock_flags)
{
int iolocked;
int ilocked;
/*
* You can't set both SHARED and EXCL for the same lock,
* and only XFS_IOLOCK_SHARED, XFS_IOLOCK_EXCL, XFS_ILOCK_SHARED,
* and XFS_ILOCK_EXCL are valid values to set in lock_flags.
*/
ASSERT((lock_flags & (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL)) !=
(XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL));
ASSERT((lock_flags & (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL)) !=
(XFS_ILOCK_SHARED | XFS_ILOCK_EXCL));
ASSERT((lock_flags & ~(XFS_LOCK_MASK | XFS_LOCK_DEP_MASK)) == 0);
iolocked = 0;
if (lock_flags & XFS_IOLOCK_EXCL) {
iolocked = mrtryupdate(&ip->i_iolock);
if (!iolocked) {
return 0;
}
} else if (lock_flags & XFS_IOLOCK_SHARED) {
iolocked = mrtryaccess(&ip->i_iolock);
if (!iolocked) {
return 0;
}
}
if (lock_flags & XFS_ILOCK_EXCL) {
ilocked = mrtryupdate(&ip->i_lock);
if (!ilocked) {
if (iolocked) {
mrunlock(&ip->i_iolock);
}
return 0;
}
} else if (lock_flags & XFS_ILOCK_SHARED) {
ilocked = mrtryaccess(&ip->i_lock);
if (!ilocked) {
if (iolocked) {
mrunlock(&ip->i_iolock);
}
return 0;
}
}
xfs_ilock_trace(ip, 2, lock_flags, (inst_t *)__return_address);
return 1;
}
/*
* xfs_iunlock() is used to drop the inode locks acquired with
* xfs_ilock() and xfs_ilock_nowait(). The caller must pass
* in the flags given to xfs_ilock() or xfs_ilock_nowait() so
* that we know which locks to drop.
*
* ip -- the inode being unlocked
* lock_flags -- this parameter indicates the inode's locks to be
* to be unlocked. See the comment for xfs_ilock() for a list
* of valid values for this parameter.
*
*/
void
xfs_iunlock(xfs_inode_t *ip,
uint lock_flags)
{
/*
* You can't set both SHARED and EXCL for the same lock,
* and only XFS_IOLOCK_SHARED, XFS_IOLOCK_EXCL, XFS_ILOCK_SHARED,
* and XFS_ILOCK_EXCL are valid values to set in lock_flags.
*/
ASSERT((lock_flags & (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL)) !=
(XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL));
ASSERT((lock_flags & (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL)) !=
(XFS_ILOCK_SHARED | XFS_ILOCK_EXCL));
ASSERT((lock_flags & ~(XFS_LOCK_MASK | XFS_IUNLOCK_NONOTIFY |
XFS_LOCK_DEP_MASK)) == 0);
ASSERT(lock_flags != 0);
if (lock_flags & (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL)) {
ASSERT(!(lock_flags & XFS_IOLOCK_SHARED) ||
(ismrlocked(&ip->i_iolock, MR_ACCESS)));
ASSERT(!(lock_flags & XFS_IOLOCK_EXCL) ||
(ismrlocked(&ip->i_iolock, MR_UPDATE)));
mrunlock(&ip->i_iolock);
}
if (lock_flags & (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL)) {
ASSERT(!(lock_flags & XFS_ILOCK_SHARED) ||
(ismrlocked(&ip->i_lock, MR_ACCESS)));
ASSERT(!(lock_flags & XFS_ILOCK_EXCL) ||
(ismrlocked(&ip->i_lock, MR_UPDATE)));
mrunlock(&ip->i_lock);
/*
* Let the AIL know that this item has been unlocked in case
* it is in the AIL and anyone is waiting on it. Don't do
* this if the caller has asked us not to.
*/
if (!(lock_flags & XFS_IUNLOCK_NONOTIFY) &&
ip->i_itemp != NULL) {
xfs_trans_unlocked_item(ip->i_mount,
(xfs_log_item_t*)(ip->i_itemp));
}
}
xfs_ilock_trace(ip, 3, lock_flags, (inst_t *)__return_address);
}
/*
* give up write locks. the i/o lock cannot be held nested
* if it is being demoted.
*/
void
xfs_ilock_demote(xfs_inode_t *ip,
uint lock_flags)
{
ASSERT(lock_flags & (XFS_IOLOCK_EXCL|XFS_ILOCK_EXCL));
ASSERT((lock_flags & ~(XFS_IOLOCK_EXCL|XFS_ILOCK_EXCL)) == 0);
if (lock_flags & XFS_ILOCK_EXCL) {
ASSERT(ismrlocked(&ip->i_lock, MR_UPDATE));
mrdemote(&ip->i_lock);
}
if (lock_flags & XFS_IOLOCK_EXCL) {
ASSERT(ismrlocked(&ip->i_iolock, MR_UPDATE));
mrdemote(&ip->i_iolock);
}
}
/*
* The following three routines simply manage the i_flock
* semaphore embedded in the inode. This semaphore synchronizes
* processes attempting to flush the in-core inode back to disk.
*/
void
xfs_iflock(xfs_inode_t *ip)
{
psema(&(ip->i_flock), PINOD|PLTWAIT);
}
int
xfs_iflock_nowait(xfs_inode_t *ip)
{
return (cpsema(&(ip->i_flock)));
}
void
xfs_ifunlock(xfs_inode_t *ip)
{
ASSERT(issemalocked(&(ip->i_flock)));
vsema(&(ip->i_flock));
}
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