android_kernel_xiaomi_sm8350/fs/xfs/xfs_iget.c
Christoph Hellwig aa72a5cf00 xfs: simplify xfs_trans_iget
xfs_trans_iget is a wrapper for xfs_iget that adds the inode to the
transaction after it is read.  Except when the inode already is in the
inode cache, in which case it returns the existing locked inode with
increment lock recursion counts.

Now, no one in the tree every decrements these lock recursion counts,
so any user of this gets a potential double unlock when both the original
owner of the inode and the xfs_trans_iget caller unlock it.  When looking
back in a git bisect in the historic XFS tree there was only one place
that decremented these counts, xfs_trans_iput.  Introduced in commit
ca25df7a840f426eb566d52667b6950b92bb84b5 by Adam Sweeney in 1993,
and removed in commit 19f899a3ab155ff6a49c0c79b06f2f61059afaf3 by
Steve Lord in 2003.  And as long as it didn't slip through git bisects
cracks never actually used in that time frame.

A quick audit of the callers of xfs_trans_iget shows that no caller
really relies on this behaviour fortunately - xfs_ialloc allows this
inode from disk so it must not be there before, and all the RT allocator
routines only every add each RT bitmap inode once.

In addition to removing lots of code and reducing the size of the inode
item this patch also avoids the double inode cache lookup in each
create/mkdir/mknod transaction.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Alex Elder <aelder@sgi.com>
Signed-off-by: Felix Blyakher <felixb@sgi.com>
2009-09-01 12:46:16 -05:00

844 lines
22 KiB
C

/*
* 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_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;
if (inode_init_always(mp->m_super, VFS_I(ip))) {
kmem_zone_free(xfs_inode_zone, 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_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
/* prevent anyone from using this yet */
VFS_I(ip)->i_state = I_NEW|I_LOCK;
return ip;
}
STATIC 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);
#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);
}
/*
* 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 inode *inode = VFS_I(ip);
struct xfs_mount *mp = ip->i_mount;
int error;
spin_lock(&ip->i_flags_lock);
/*
* 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)) {
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) {
xfs_itrace_exit_tag(ip, "xfs_iget.alloc");
/*
* We need to set XFS_INEW atomically with clearing the
* reclaimable tag so that we do have an indicator of the
* inode still being initialized.
*/
ip->i_flags |= XFS_INEW;
ip->i_flags &= ~XFS_IRECLAIMABLE;
__xfs_inode_clear_reclaim_tag(mp, pag, ip);
spin_unlock(&ip->i_flags_lock);
read_unlock(&pag->pag_ici_lock);
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.
*/
read_lock(&pag->pag_ici_lock);
spin_lock(&ip->i_flags_lock);
ip->i_flags &= ~XFS_INEW;
ip->i_flags |= XFS_IRECLAIMABLE;
__xfs_inode_set_reclaim_tag(pag, ip);
goto out_error;
}
inode->i_state = I_LOCK|I_NEW;
} else {
/* If the VFS inode is being torn down, pause and try again. */
if (!igrab(inode)) {
error = EAGAIN;
goto out_error;
}
/* We've got a live one. */
spin_unlock(&ip->i_flags_lock);
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:
spin_unlock(&ip->i_flags_lock);
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:
__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.
* 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;
}
/*
* 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);
xfs_inode_free(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 */