diff options
Diffstat (limited to 'fs/xfs/xfs_iget.c')
| -rw-r--r-- | fs/xfs/xfs_iget.c | 736 |
1 files changed, 736 insertions, 0 deletions
diff --git a/fs/xfs/xfs_iget.c b/fs/xfs/xfs_iget.c new file mode 100644 index 00000000..bcc6c249 --- /dev/null +++ b/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); +} |