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kernel-ark/fs/xfs/xfs_iget.c
Christoph Hellwig 7d095257e3 xfs: kill xfs_qmops 
Kill the quota ops function vector and replace it with direct calls or
stubs in the CONFIG_XFS_QUOTA=n case.

Make sure we check XFS_IS_QUOTA_RUNNING in the right spots.  We can remove
the number of those checks because the XFS_TRANS_DQ_DIRTY flag can't be set
otherwise.

This brings us back closer to the way this code worked in IRIX and earlier
Linux versions, but we keep a lot of the more useful factoring of common
code.

Eventually we should also kill xfs_qm_bhv.c, but that's left for a later
patch.

Reduces the size of the source code by about 250 lines and the size of
XFS module by about 1.5 kilobytes with quotas enabled:

   text	   data	    bss	    dec	    hex	filename
 615957	   2960	   3848	 622765	  980ad	fs/xfs/xfs.o
 617231	   3152	   3848	 624231	  98667	fs/xfs/xfs.o.old

Fallout:

 - xfs_qm_dqattach is split into xfs_qm_dqattach_locked which expects
   the inode locked and xfs_qm_dqattach which does the locking around it,
   thus removing XFS_QMOPT_ILOCKED.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Eric Sandeen <sandeen@sandeen.net>
2009-06-08 15:33:32 +02:00

863 lines
23 KiB
C
Raw Blame History

/*
* 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"
#include "xfs_trans_priv.h"
#include "xfs_inode_item.h"
#include "xfs_bmap.h"
#include "xfs_btree_trace.h"
#include "xfs_dir2_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;
ASSERT(atomic_read(&ip->i_iocount) == 0);
ASSERT(atomic_read(&ip->i_pincount) == 0);
ASSERT(!spin_is_locked(&ip->i_flags_lock));
ASSERT(completion_done(&ip->i_flush));
/* 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_update_core = 0;
ip->i_update_size = 0;
ip->i_delayed_blks = 0;
memset(&ip->i_d, 0, sizeof(xfs_icdinode_t));
ip->i_size = 0;
ip->i_new_size = 0;
/*
* Initialize inode's trace buffers.
*/
#ifdef XFS_INODE_TRACE
ip->i_trace = ktrace_alloc(INODE_TRACE_SIZE, KM_NOFS);
#endif
#ifdef XFS_BMAP_TRACE
ip->i_xtrace = ktrace_alloc(XFS_BMAP_KTRACE_SIZE, KM_NOFS);
#endif
#ifdef XFS_BTREE_TRACE
ip->i_btrace = ktrace_alloc(XFS_BMBT_KTRACE_SIZE, KM_NOFS);
#endif
#ifdef XFS_RW_TRACE
ip->i_rwtrace = ktrace_alloc(XFS_RW_KTRACE_SIZE, KM_NOFS);
#endif
#ifdef XFS_ILOCK_TRACE
ip->i_lock_trace = ktrace_alloc(XFS_ILOCK_KTRACE_SIZE, KM_NOFS);
#endif
#ifdef XFS_DIR2_TRACE
ip->i_dir_trace = ktrace_alloc(XFS_DIR2_KTRACE_SIZE, KM_NOFS);
#endif
/*
* Now initialise the VFS inode. We do this after the xfs_inode
* initialisation as internal failures will result in ->destroy_inode
* being called and that will pass down through the reclaim path and
* free the XFS inode. This path requires the XFS inode to already be
* initialised. Hence if this call fails, the xfs_inode has already
* been freed and we should not reference it at all in the error
* handling.
*/
if (!inode_init_always(mp->m_super, VFS_I(ip)))
return NULL;
/* prevent anyone from using this yet */
VFS_I(ip)->i_state = I_NEW|I_LOCK;
return ip;
}
/*
* 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,
int flags,
int lock_flags) __releases(pag->pag_ici_lock)
{
struct xfs_mount *mp = ip->i_mount;
int error = EAGAIN;
/*
* If INEW is set this inode is being set up
* If IRECLAIM is set this inode is being torn down
* Pause and try again.
*/
if (xfs_iflags_test(ip, (XFS_INEW|XFS_IRECLAIM))) {
XFS_STATS_INC(xs_ig_frecycle);
goto out_error;
}
/* If IRECLAIMABLE is set, we've torn down the vfs inode part */
if (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)) {
error = ENOENT;
goto out_error;
}
xfs_itrace_exit_tag(ip, "xfs_iget.alloc");
/*
* We need to re-initialise the VFS inode as it has been
* 'freed' by the VFS. Do this here so we can deal with
* errors cleanly, then tag it so it can be set up correctly
* later.
*/
if (!inode_init_always(mp->m_super, VFS_I(ip))) {
error = ENOMEM;
goto out_error;
}
/*
* We must set the XFS_INEW flag before clearing the
* XFS_IRECLAIMABLE flag so that if a racing lookup does
* not find the XFS_IRECLAIMABLE above but has the igrab()
* below succeed we can safely check XFS_INEW to detect
* that this inode is still being initialised.
*/
xfs_iflags_set(ip, XFS_INEW);
xfs_iflags_clear(ip, XFS_IRECLAIMABLE);
/* clear the radix tree reclaim flag as well. */
__xfs_inode_clear_reclaim_tag(mp, pag, ip);
} else if (!igrab(VFS_I(ip))) {
/* If the VFS inode is being torn down, pause and try again. */
XFS_STATS_INC(xs_ig_frecycle);
goto out_error;
} else if (xfs_iflags_test(ip, XFS_INEW)) {
/*
* We are racing with another cache hit that is
* currently recycling this inode out of the XFS_IRECLAIMABLE
* state. Wait for the initialisation to complete before
* continuing.
*/
wait_on_inode(VFS_I(ip));
}
if (ip->i_d.di_mode == 0 && !(flags & XFS_IGET_CREATE)) {
error = ENOENT;
iput(VFS_I(ip));
goto out_error;
}
/* We've got a live one. */
read_unlock(&pag->pag_ici_lock);
if (lock_flags != 0)
xfs_ilock(ip, lock_flags);
xfs_iflags_clear(ip, XFS_ISTALE);
xfs_itrace_exit_tag(ip, "xfs_iget.found");
XFS_STATS_INC(xs_ig_found);
return 0;
out_error:
read_unlock(&pag->pag_ici_lock);
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,
xfs_daddr_t bno,
int flags,
int lock_flags) __releases(pag->pag_ici_lock)
{
struct xfs_inode *ip;
int error;
unsigned long first_index, mask;
xfs_agino_t agino = XFS_INO_TO_AGINO(mp, ino);
ip = xfs_inode_alloc(mp, ino);
if (!ip)
return ENOMEM;
error = xfs_iread(mp, tp, ip, bno, flags);
if (error)
goto out_destroy;
xfs_itrace_exit_tag(ip, "xfs_iget.alloc");
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();
}
mask = ~(((XFS_INODE_CLUSTER_SIZE(mp) >> mp->m_sb.sb_inodelog)) - 1);
first_index = agino & mask;
write_lock(&pag->pag_ici_lock);
/* insert the new inode */
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;
}
/* These values _must_ be set before releasing the radix tree lock! */
ip->i_udquot = ip->i_gdquot = NULL;
xfs_iflags_set(ip, XFS_INEW);
write_unlock(&pag->pag_ici_lock);
radix_tree_preload_end();
*ipp = ip;
return 0;
out_preload_end:
write_unlock(&pag->pag_ici_lock);
radix_tree_preload_end();
if (lock_flags)
xfs_iunlock(ip, lock_flags);
out_destroy:
xfs_destroy_inode(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.
* bno -- the block number starting the buffer containing the inode,
* if known (as by bulkstat), else 0.
*/
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)
{
xfs_inode_t *ip;
int error;
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:
error = 0;
read_lock(&pag->pag_ici_lock);
ip = radix_tree_lookup(&pag->pag_ici_root, agino);
if (ip) {
error = xfs_iget_cache_hit(pag, ip, flags, lock_flags);
if (error)
goto out_error_or_again;
} else {
read_unlock(&pag->pag_ici_lock);
XFS_STATS_INC(xs_ig_missed);
error = xfs_iget_cache_miss(mp, pag, tp, ino, &ip, bno,
flags, lock_flags);
if (error)
goto out_error_or_again;
}
xfs_put_perag(mp, pag);
*ipp = ip;
ASSERT(ip->i_df.if_ext_max ==
XFS_IFORK_DSIZE(ip) / sizeof(xfs_bmbt_rec_t));
/*
* 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_put_perag(mp, pag);
return error;
}
/*
* 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)
{
xfs_itrace_entry(ip);
xfs_iunlock(ip, lock_flags);
IRELE(ip);
}
/*
* Special iput for brand-new inodes that are still locked
*/
void
xfs_iput_new(
xfs_inode_t *ip,
uint lock_flags)
{
struct inode *inode = VFS_I(ip);
xfs_itrace_entry(ip);
if ((ip->i_d.di_mode == 0)) {
ASSERT(!xfs_iflags_test(ip, XFS_IRECLAIMABLE));
make_bad_inode(inode);
}
if (inode->i_state & I_NEW)
unlock_new_inode(inode);
if (lock_flags)
xfs_iunlock(ip, lock_flags);
IRELE(ip);
}
/*
* This is called free all the memory associated with an inode.
* It must free the inode itself and any buffers allocated for
* if_extents/if_data and if_broot. It must also free the lock
* associated with the inode.
*
* Note: because we don't initialise everything on reallocation out
* of the zone, we must ensure we nullify everything correctly before
* freeing the structure.
*/
void
xfs_ireclaim(
struct xfs_inode *ip)
{
struct xfs_mount *mp = ip->i_mount;
struct xfs_perag *pag;
XFS_STATS_INC(xs_ig_reclaims);
/*
* Remove the inode from the per-AG radix tree. It doesn't matter
* if it was never added to it because radix_tree_delete can deal
* with that case just fine.
*/
pag = xfs_get_perag(mp, ip->i_ino);
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);
/*
* Here we do an (almost) spurious inode lock in order to coordinate
* with inode cache radix tree lookups. This is because the lookup
* can reference the inodes in the cache without taking references.
*
* We make that OK here by ensuring that we wait until the inode is
* unlocked after the lookup before we go ahead and free it. We get
* both the ilock and the iolock because the code may need to drop the
* ilock one but will still hold the iolock.
*/
xfs_ilock(ip, XFS_ILOCK_EXCL | XFS_IOLOCK_EXCL);
xfs_qm_dqdetach(ip);
xfs_iunlock(ip, XFS_ILOCK_EXCL | XFS_IOLOCK_EXCL);
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);
#ifdef XFS_INODE_TRACE
ktrace_free(ip->i_trace);
#endif
#ifdef XFS_BMAP_TRACE
ktrace_free(ip->i_xtrace);
#endif
#ifdef XFS_BTREE_TRACE
ktrace_free(ip->i_btrace);
#endif
#ifdef XFS_RW_TRACE
ktrace_free(ip->i_rwtrace);
#endif
#ifdef XFS_ILOCK_TRACE
ktrace_free(ip->i_lock_trace);
#endif
#ifdef XFS_DIR2_TRACE
ktrace_free(ip->i_dir_trace);
#endif
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_iocount) == 0);
ASSERT(atomic_read(&ip->i_pincount) == 0);
ASSERT(!spin_is_locked(&ip->i_flags_lock));
ASSERT(completion_done(&ip->i_flush));
kmem_zone_free(xfs_inode_zone, ip);
}
/*
* 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)
{
/*
* 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;
}
xfs_ilock_trace(ip, 2, lock_flags, (inst_t *)__return_address);
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_IUNLOCK_NONOTIFY |
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);
if ((lock_flags & (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL)) &&
!(lock_flags & XFS_IUNLOCK_NONOTIFY) && ip->i_itemp) {
/*
* 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.
*/
xfs_trans_unlocked_item(ip->i_itemp->ili_item.li_ailp,
(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)
mrdemote(&ip->i_lock);
if (lock_flags & XFS_IOLOCK_EXCL)
mrdemote(&ip->i_iolock);
}
#ifdef DEBUG
/*
* Debug-only routine, without additional rw_semaphore APIs, we can
* now only answer requests regarding whether we hold the lock for write
* (reader state is outside our visibility, we only track writer state).
*
* Note: this means !xfs_isilocked would give false positives, so don't do that.
*/
int
xfs_isilocked(
xfs_inode_t *ip,
uint lock_flags)
{
if ((lock_flags & (XFS_ILOCK_EXCL|XFS_ILOCK_SHARED)) ==
XFS_ILOCK_EXCL) {
if (!ip->i_lock.mr_writer)
return 0;
}
if ((lock_flags & (XFS_IOLOCK_EXCL|XFS_IOLOCK_SHARED)) ==
XFS_IOLOCK_EXCL) {
if (!ip->i_iolock.mr_writer)
return 0;
}
return 1;
}
#endif
#ifdef XFS_INODE_TRACE
#define KTRACE_ENTER(ip, vk, s, line, ra) \
ktrace_enter((ip)->i_trace, \
/* 0 */ (void *)(__psint_t)(vk), \
/* 1 */ (void *)(s), \
/* 2 */ (void *)(__psint_t) line, \
/* 3 */ (void *)(__psint_t)atomic_read(&VFS_I(ip)->i_count), \
/* 4 */ (void *)(ra), \
/* 5 */ NULL, \
/* 6 */ (void *)(__psint_t)current_cpu(), \
/* 7 */ (void *)(__psint_t)current_pid(), \
/* 8 */ (void *)__return_address, \
/* 9 */ NULL, NULL, NULL, NULL, NULL, NULL, NULL)
/*
* Vnode tracing code.
*/
void
_xfs_itrace_entry(xfs_inode_t *ip, const char *func, inst_t *ra)
{
KTRACE_ENTER(ip, INODE_KTRACE_ENTRY, func, 0, ra);
}
void
_xfs_itrace_exit(xfs_inode_t *ip, const char *func, inst_t *ra)
{
KTRACE_ENTER(ip, INODE_KTRACE_EXIT, func, 0, ra);
}
void
xfs_itrace_hold(xfs_inode_t *ip, char *file, int line, inst_t *ra)
{
KTRACE_ENTER(ip, INODE_KTRACE_HOLD, file, line, ra);
}
void
_xfs_itrace_ref(xfs_inode_t *ip, char *file, int line, inst_t *ra)
{
KTRACE_ENTER(ip, INODE_KTRACE_REF, file, line, ra);
}
void
xfs_itrace_rele(xfs_inode_t *ip, char *file, int line, inst_t *ra)
{
KTRACE_ENTER(ip, INODE_KTRACE_RELE, file, line, ra);
}
#endif /* XFS_INODE_TRACE */
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