zte's code,first commit
Change-Id: I9a04da59e459a9bc0d67f101f700d9d7dc8d681b
diff --git a/ap/os/linux/linux-3.4.x/fs/xfs/xfs_iget.c b/ap/os/linux/linux-3.4.x/fs/xfs/xfs_iget.c
new file mode 100644
index 0000000..bcc6c24
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/fs/xfs/xfs_iget.c
@@ -0,0 +1,736 @@
+/*
+ * 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_acl.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_mount.h"
+#include "xfs_bmap_btree.h"
+#include "xfs_alloc_btree.h"
+#include "xfs_ialloc_btree.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"
+#include "xfs_trans_priv.h"
+#include "xfs_inode_item.h"
+#include "xfs_bmap.h"
+#include "xfs_trace.h"
+
+
+/*
+ * Define xfs inode iolock lockdep classes. We need to ensure that all active
+ * inodes are considered the same for lockdep purposes, including inodes that
+ * are recycled through the XFS_IRECLAIMABLE state. This is the the only way to
+ * guarantee the locks are considered the same when there are multiple lock
+ * initialisation siteѕ. Also, define a reclaimable inode class so it is
+ * obvious in lockdep reports which class the report is against.
+ */
+static struct lock_class_key xfs_iolock_active;
+struct lock_class_key xfs_iolock_reclaimable;
+
+/*
+ * Allocate and initialise an xfs_inode.
+ */
+STATIC struct xfs_inode *
+xfs_inode_alloc(
+ struct xfs_mount *mp,
+ xfs_ino_t ino)
+{
+ struct xfs_inode *ip;
+
+ /*
+ * if this didn't occur in transactions, we could use
+ * KM_MAYFAIL and return NULL here on ENOMEM. Set the
+ * code up to do this anyway.
+ */
+ ip = kmem_zone_alloc(xfs_inode_zone, KM_SLEEP);
+ if (!ip)
+ return NULL;
+ if (inode_init_always(mp->m_super, VFS_I(ip))) {
+ kmem_zone_free(xfs_inode_zone, ip);
+ return NULL;
+ }
+
+ ASSERT(atomic_read(&ip->i_pincount) == 0);
+ ASSERT(!spin_is_locked(&ip->i_flags_lock));
+ ASSERT(!xfs_isiflocked(ip));
+ ASSERT(ip->i_ino == 0);
+
+ mrlock_init(&ip->i_iolock, MRLOCK_BARRIER, "xfsio", ip->i_ino);
+ lockdep_set_class_and_name(&ip->i_iolock.mr_lock,
+ &xfs_iolock_active, "xfs_iolock_active");
+
+ /* initialise the xfs inode */
+ ip->i_ino = ino;
+ ip->i_mount = mp;
+ memset(&ip->i_imap, 0, sizeof(struct xfs_imap));
+ ip->i_afp = NULL;
+ memset(&ip->i_df, 0, sizeof(xfs_ifork_t));
+ ip->i_flags = 0;
+ ip->i_delayed_blks = 0;
+ memset(&ip->i_d, 0, sizeof(xfs_icdinode_t));
+
+ return ip;
+}
+
+STATIC void
+xfs_inode_free_callback(
+ struct rcu_head *head)
+{
+ struct inode *inode = container_of(head, struct inode, i_rcu);
+ struct xfs_inode *ip = XFS_I(inode);
+
+ kmem_zone_free(xfs_inode_zone, ip);
+}
+
+void
+xfs_inode_free(
+ struct xfs_inode *ip)
+{
+ switch (ip->i_d.di_mode & S_IFMT) {
+ case S_IFREG:
+ case S_IFDIR:
+ case S_IFLNK:
+ xfs_idestroy_fork(ip, XFS_DATA_FORK);
+ break;
+ }
+
+ if (ip->i_afp)
+ xfs_idestroy_fork(ip, XFS_ATTR_FORK);
+
+ if (ip->i_itemp) {
+ /*
+ * Only if we are shutting down the fs will we see an
+ * inode still in the AIL. If it is there, we should remove
+ * it to prevent a use-after-free from occurring.
+ */
+ xfs_log_item_t *lip = &ip->i_itemp->ili_item;
+ struct xfs_ail *ailp = lip->li_ailp;
+
+ ASSERT(((lip->li_flags & XFS_LI_IN_AIL) == 0) ||
+ XFS_FORCED_SHUTDOWN(ip->i_mount));
+ if (lip->li_flags & XFS_LI_IN_AIL) {
+ spin_lock(&ailp->xa_lock);
+ if (lip->li_flags & XFS_LI_IN_AIL)
+ xfs_trans_ail_delete(ailp, lip);
+ else
+ spin_unlock(&ailp->xa_lock);
+ }
+ xfs_inode_item_destroy(ip);
+ ip->i_itemp = NULL;
+ }
+
+ /* asserts to verify all state is correct here */
+ ASSERT(atomic_read(&ip->i_pincount) == 0);
+ ASSERT(!spin_is_locked(&ip->i_flags_lock));
+ ASSERT(!xfs_isiflocked(ip));
+
+ /*
+ * Because we use RCU freeing we need to ensure the inode always
+ * appears to be reclaimed with an invalid inode number when in the
+ * free state. The ip->i_flags_lock provides the barrier against lookup
+ * races.
+ */
+ spin_lock(&ip->i_flags_lock);
+ ip->i_flags = XFS_IRECLAIM;
+ ip->i_ino = 0;
+ spin_unlock(&ip->i_flags_lock);
+
+ call_rcu(&VFS_I(ip)->i_rcu, xfs_inode_free_callback);
+}
+
+/*
+ * Check the validity of the inode we just found it the cache
+ */
+static int
+xfs_iget_cache_hit(
+ struct xfs_perag *pag,
+ struct xfs_inode *ip,
+ xfs_ino_t ino,
+ int flags,
+ int lock_flags) __releases(RCU)
+{
+ struct inode *inode = VFS_I(ip);
+ struct xfs_mount *mp = ip->i_mount;
+ int error;
+
+ /*
+ * check for re-use of an inode within an RCU grace period due to the
+ * radix tree nodes not being updated yet. We monitor for this by
+ * setting the inode number to zero before freeing the inode structure.
+ * If the inode has been reallocated and set up, then the inode number
+ * will not match, so check for that, too.
+ */
+ spin_lock(&ip->i_flags_lock);
+ if (ip->i_ino != ino) {
+ trace_xfs_iget_skip(ip);
+ XFS_STATS_INC(xs_ig_frecycle);
+ error = EAGAIN;
+ goto out_error;
+ }
+
+
+ /*
+ * If we are racing with another cache hit that is currently
+ * instantiating this inode or currently recycling it out of
+ * reclaimabe state, wait for the initialisation to complete
+ * before continuing.
+ *
+ * XXX(hch): eventually we should do something equivalent to
+ * wait_on_inode to wait for these flags to be cleared
+ * instead of polling for it.
+ */
+ if (ip->i_flags & (XFS_INEW|XFS_IRECLAIM)) {
+ trace_xfs_iget_skip(ip);
+ XFS_STATS_INC(xs_ig_frecycle);
+ error = EAGAIN;
+ goto out_error;
+ }
+
+ /*
+ * If lookup is racing with unlink return an error immediately.
+ */
+ if (ip->i_d.di_mode == 0 && !(flags & XFS_IGET_CREATE)) {
+ error = ENOENT;
+ goto out_error;
+ }
+
+ /*
+ * If IRECLAIMABLE is set, we've torn down the VFS inode already.
+ * Need to carefully get it back into useable state.
+ */
+ if (ip->i_flags & XFS_IRECLAIMABLE) {
+ trace_xfs_iget_reclaim(ip);
+
+ /*
+ * We need to set XFS_IRECLAIM to prevent xfs_reclaim_inode
+ * from stomping over us while we recycle the inode. We can't
+ * clear the radix tree reclaimable tag yet as it requires
+ * pag_ici_lock to be held exclusive.
+ */
+ ip->i_flags |= XFS_IRECLAIM;
+
+ spin_unlock(&ip->i_flags_lock);
+ rcu_read_unlock();
+
+ error = -inode_init_always(mp->m_super, inode);
+ if (error) {
+ /*
+ * Re-initializing the inode failed, and we are in deep
+ * trouble. Try to re-add it to the reclaim list.
+ */
+ rcu_read_lock();
+ spin_lock(&ip->i_flags_lock);
+
+ ip->i_flags &= ~(XFS_INEW | XFS_IRECLAIM);
+ ASSERT(ip->i_flags & XFS_IRECLAIMABLE);
+ trace_xfs_iget_reclaim_fail(ip);
+ goto out_error;
+ }
+
+ spin_lock(&pag->pag_ici_lock);
+ spin_lock(&ip->i_flags_lock);
+
+ /*
+ * Clear the per-lifetime state in the inode as we are now
+ * effectively a new inode and need to return to the initial
+ * state before reuse occurs.
+ */
+ ip->i_flags &= ~XFS_IRECLAIM_RESET_FLAGS;
+ ip->i_flags |= XFS_INEW;
+ __xfs_inode_clear_reclaim_tag(mp, pag, ip);
+ inode->i_state = I_NEW;
+
+ ASSERT(!rwsem_is_locked(&ip->i_iolock.mr_lock));
+ mrlock_init(&ip->i_iolock, MRLOCK_BARRIER, "xfsio", ip->i_ino);
+ lockdep_set_class_and_name(&ip->i_iolock.mr_lock,
+ &xfs_iolock_active, "xfs_iolock_active");
+
+ spin_unlock(&ip->i_flags_lock);
+ spin_unlock(&pag->pag_ici_lock);
+ } else {
+ /* If the VFS inode is being torn down, pause and try again. */
+ if (!igrab(inode)) {
+ trace_xfs_iget_skip(ip);
+ error = EAGAIN;
+ goto out_error;
+ }
+
+ /* We've got a live one. */
+ spin_unlock(&ip->i_flags_lock);
+ rcu_read_unlock();
+ trace_xfs_iget_hit(ip);
+ }
+
+ if (lock_flags != 0)
+ xfs_ilock(ip, lock_flags);
+
+ xfs_iflags_clear(ip, XFS_ISTALE | XFS_IDONTCACHE);
+ XFS_STATS_INC(xs_ig_found);
+
+ return 0;
+
+out_error:
+ spin_unlock(&ip->i_flags_lock);
+ rcu_read_unlock();
+ return error;
+}
+
+
+static int
+xfs_iget_cache_miss(
+ struct xfs_mount *mp,
+ struct xfs_perag *pag,
+ xfs_trans_t *tp,
+ xfs_ino_t ino,
+ struct xfs_inode **ipp,
+ int flags,
+ int lock_flags)
+{
+ struct xfs_inode *ip;
+ int error;
+ xfs_agino_t agino = XFS_INO_TO_AGINO(mp, ino);
+ int iflags;
+
+ ip = xfs_inode_alloc(mp, ino);
+ if (!ip)
+ return ENOMEM;
+
+ error = xfs_iread(mp, tp, ip, flags);
+ if (error)
+ goto out_destroy;
+
+ trace_xfs_iget_miss(ip);
+
+ if ((ip->i_d.di_mode == 0) && !(flags & XFS_IGET_CREATE)) {
+ error = ENOENT;
+ goto out_destroy;
+ }
+
+ /*
+ * Preload the radix tree so we can insert safely under the
+ * write spinlock. Note that we cannot sleep inside the preload
+ * region.
+ */
+ if (radix_tree_preload(GFP_KERNEL)) {
+ error = EAGAIN;
+ goto out_destroy;
+ }
+
+ /*
+ * Because the inode hasn't been added to the radix-tree yet it can't
+ * be found by another thread, so we can do the non-sleeping lock here.
+ */
+ if (lock_flags) {
+ if (!xfs_ilock_nowait(ip, lock_flags))
+ BUG();
+ }
+
+ /*
+ * These values must be set before inserting the inode into the radix
+ * tree as the moment it is inserted a concurrent lookup (allowed by the
+ * RCU locking mechanism) can find it and that lookup must see that this
+ * is an inode currently under construction (i.e. that XFS_INEW is set).
+ * The ip->i_flags_lock that protects the XFS_INEW flag forms the
+ * memory barrier that ensures this detection works correctly at lookup
+ * time.
+ */
+ iflags = XFS_INEW;
+ if (flags & XFS_IGET_DONTCACHE)
+ iflags |= XFS_IDONTCACHE;
+ ip->i_udquot = ip->i_gdquot = NULL;
+ xfs_iflags_set(ip, iflags);
+
+ /* insert the new inode */
+ spin_lock(&pag->pag_ici_lock);
+ error = radix_tree_insert(&pag->pag_ici_root, agino, ip);
+ if (unlikely(error)) {
+ WARN_ON(error != -EEXIST);
+ XFS_STATS_INC(xs_ig_dup);
+ error = EAGAIN;
+ goto out_preload_end;
+ }
+ spin_unlock(&pag->pag_ici_lock);
+ radix_tree_preload_end();
+
+ *ipp = ip;
+ return 0;
+
+out_preload_end:
+ spin_unlock(&pag->pag_ici_lock);
+ radix_tree_preload_end();
+ if (lock_flags)
+ xfs_iunlock(ip, lock_flags);
+out_destroy:
+ __destroy_inode(VFS_I(ip));
+ xfs_inode_free(ip);
+ return error;
+}
+
+/*
+ * 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, initialise the vfs inode
+ * if necessary.
+ *
+ * If it is not in core, read it in from the file system's device,
+ * add it to the cache and initialise the vfs inode.
+ *
+ * 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.
+ */
+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_inode_t *ip;
+ int error;
+ xfs_perag_t *pag;
+ xfs_agino_t agino;
+
+ /*
+ * xfs_reclaim_inode() uses the ILOCK to ensure an inode
+ * doesn't get freed while it's being referenced during a
+ * radix tree traversal here. It assumes this function
+ * aqcuires only the ILOCK (and therefore it has no need to
+ * involve the IOLOCK in this synchronization).
+ */
+ ASSERT((lock_flags & (XFS_IOLOCK_EXCL | XFS_IOLOCK_SHARED)) == 0);
+
+ /* reject inode numbers outside existing AGs */
+ if (!ino || XFS_INO_TO_AGNO(mp, ino) >= mp->m_sb.sb_agcount)
+ return EINVAL;
+
+ /* get the perag structure and ensure that it's inode capable */
+ pag = xfs_perag_get(mp, XFS_INO_TO_AGNO(mp, ino));
+ agino = XFS_INO_TO_AGINO(mp, ino);
+
+again:
+ error = 0;
+ rcu_read_lock();
+ ip = radix_tree_lookup(&pag->pag_ici_root, agino);
+
+ if (ip) {
+ error = xfs_iget_cache_hit(pag, ip, ino, flags, lock_flags);
+ if (error)
+ goto out_error_or_again;
+ } else {
+ rcu_read_unlock();
+ XFS_STATS_INC(xs_ig_missed);
+
+ error = xfs_iget_cache_miss(mp, pag, tp, ino, &ip,
+ flags, lock_flags);
+ if (error)
+ goto out_error_or_again;
+ }
+ xfs_perag_put(pag);
+
+ *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.
+ */
+ if (xfs_iflags_test(ip, XFS_INEW) && ip->i_d.di_mode != 0)
+ xfs_setup_inode(ip);
+ return 0;
+
+out_error_or_again:
+ if (error == EAGAIN) {
+ delay(1);
+ goto again;
+ }
+ xfs_perag_put(pag);
+ return error;
+}
+
+/*
+ * 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));
+
+ trace_xfs_ilock(ip, lock_flags, _RET_IP_);
+}
+
+/*
+ * 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)
+{
+ /*
+ * 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) {
+ if (!mrtryupdate(&ip->i_iolock))
+ goto out;
+ } else if (lock_flags & XFS_IOLOCK_SHARED) {
+ if (!mrtryaccess(&ip->i_iolock))
+ goto out;
+ }
+ if (lock_flags & XFS_ILOCK_EXCL) {
+ if (!mrtryupdate(&ip->i_lock))
+ goto out_undo_iolock;
+ } else if (lock_flags & XFS_ILOCK_SHARED) {
+ if (!mrtryaccess(&ip->i_lock))
+ goto out_undo_iolock;
+ }
+ trace_xfs_ilock_nowait(ip, lock_flags, _RET_IP_);
+ return 1;
+
+ out_undo_iolock:
+ if (lock_flags & XFS_IOLOCK_EXCL)
+ mrunlock_excl(&ip->i_iolock);
+ else if (lock_flags & XFS_IOLOCK_SHARED)
+ mrunlock_shared(&ip->i_iolock);
+ out:
+ return 0;
+}
+
+/*
+ * 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_LOCK_DEP_MASK)) == 0);
+ ASSERT(lock_flags != 0);
+
+ if (lock_flags & XFS_IOLOCK_EXCL)
+ mrunlock_excl(&ip->i_iolock);
+ else if (lock_flags & XFS_IOLOCK_SHARED)
+ mrunlock_shared(&ip->i_iolock);
+
+ if (lock_flags & XFS_ILOCK_EXCL)
+ mrunlock_excl(&ip->i_lock);
+ else if (lock_flags & XFS_ILOCK_SHARED)
+ mrunlock_shared(&ip->i_lock);
+
+ trace_xfs_iunlock(ip, lock_flags, _RET_IP_);
+}
+
+/*
+ * 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)
+ mrdemote(&ip->i_lock);
+ if (lock_flags & XFS_IOLOCK_EXCL)
+ mrdemote(&ip->i_iolock);
+
+ trace_xfs_ilock_demote(ip, lock_flags, _RET_IP_);
+}
+
+#ifdef DEBUG
+int
+xfs_isilocked(
+ xfs_inode_t *ip,
+ uint lock_flags)
+{
+ if (lock_flags & (XFS_ILOCK_EXCL|XFS_ILOCK_SHARED)) {
+ if (!(lock_flags & XFS_ILOCK_SHARED))
+ return !!ip->i_lock.mr_writer;
+ return rwsem_is_locked(&ip->i_lock.mr_lock);
+ }
+
+ if (lock_flags & (XFS_IOLOCK_EXCL|XFS_IOLOCK_SHARED)) {
+ if (!(lock_flags & XFS_IOLOCK_SHARED))
+ return !!ip->i_iolock.mr_writer;
+ return rwsem_is_locked(&ip->i_iolock.mr_lock);
+ }
+
+ ASSERT(0);
+ return 0;
+}
+#endif
+
+void
+__xfs_iflock(
+ struct xfs_inode *ip)
+{
+ wait_queue_head_t *wq = bit_waitqueue(&ip->i_flags, __XFS_IFLOCK_BIT);
+ DEFINE_WAIT_BIT(wait, &ip->i_flags, __XFS_IFLOCK_BIT);
+
+ do {
+ prepare_to_wait_exclusive(wq, &wait.wait, TASK_UNINTERRUPTIBLE);
+ if (xfs_isiflocked(ip))
+ io_schedule();
+ } while (!xfs_iflock_nowait(ip));
+
+ finish_wait(wq, &wait.wait);
+}