diff options
Diffstat (limited to 'fs/xfs/xfs_iget.c')
| -rw-r--r-- | fs/xfs/xfs_iget.c | 705 |
1 files changed, 0 insertions, 705 deletions
diff --git a/fs/xfs/xfs_iget.c b/fs/xfs/xfs_iget.c deleted file mode 100644 index 784a803383ec..000000000000 --- a/fs/xfs/xfs_iget.c +++ /dev/null @@ -1,705 +0,0 @@ -/* - * 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_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" - - -/* - * 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); - - /* 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) { - ASSERT(!(ip->i_itemp->ili_item.li_flags & XFS_LI_IN_AIL)); - 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); - - 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. Since we can be called from transaction context, don't - * recurse into the file system. - */ - if (radix_tree_preload(GFP_NOFS)) { - 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); -} |