/*
* Release the buffer associated with the buf log item. If there is no dirty
* logged data associated with the buffer recorded in the buf log item, then
* free the buf log item and remove the reference to it in the buffer.
*
* This call ignores the recursion count. It is only called when the buffer
* should REALLY be unlocked, regardless of the recursion count.
*
* We unconditionally drop the transaction's reference to the log item. If the
* item was logged, then another reference was taken when it was pinned, so we
* can safely drop the transaction reference now. This also allows us to avoid
* potential races with the unpin code freeing the bli by not referencing the
* bli after we've dropped the reference count.
*
* If the XFS_BLI_HOLD flag is set in the buf log item, then free the log item
* if necessary but do not unlock the buffer. This is for support of
* xfs_trans_bhold(). Make sure the XFS_BLI_HOLD field is cleared if we don't
* free the item.
*/
STATIC void
xfs_buf_item_unlock(
struct xfs_log_item *lip)
{
struct xfs_buf_log_item *bip = BUF_ITEM(lip);
struct xfs_buf *bp = bip->bli_buf;
bool clean;
bool aborted;
int flags;
/* Clear the buffer's association with this transaction. */
bp->b_transp = NULL;
/*
* If this is a transaction abort, don't return early. Instead, allow
* the brelse to happen. Normally it would be done for stale
* (cancelled) buffers at unpin time, but we'll never go through the
* pin/unpin cycle if we abort inside commit.
*/
aborted = (lip->li_flags & XFS_LI_ABORTED) ? true : false;
/*
* Before possibly freeing the buf item, copy the per-transaction state
* so we can reference it safely later after clearing it from the
* buffer log item.
*/
flags = bip->bli_flags;
bip->bli_flags &= ~(XFS_BLI_LOGGED | XFS_BLI_HOLD | XFS_BLI_ORDERED);
/*
* If the buf item is marked stale, then don't do anything. We'll
* unlock the buffer and free the buf item when the buffer is unpinned
* for the last time.
*/
if (flags & XFS_BLI_STALE) {
trace_xfs_buf_item_unlock_stale(bip);
ASSERT(bip->__bli_format.blf_flags & XFS_BLF_CANCEL);
if (!aborted) {
atomic_dec(&bip->bli_refcount);
return;
}
}
trace_xfs_buf_item_unlock(bip);
/*
* If the buf item isn't tracking any data, free it, otherwise drop the
* reference we hold to it. If we are aborting the transaction, this may
* be the only reference to the buf item, so we free it anyway
* regardless of whether it is dirty or not. A dirty abort implies a
* shutdown, anyway.
*
* Ordered buffers are dirty but may have no recorded changes, so ensure
* we only release clean items here.
*/
clean = (flags & XFS_BLI_DIRTY) ? false : true;
if (clean) {
int i;
for (i = 0; i < bip->bli_format_count; i++) {
if (!xfs_bitmap_empty(bip->bli_formats[i].blf_data_map,
bip->bli_formats[i].blf_map_size)) {
clean = false;
break;
}
}
}
/*
* Clean buffers, by definition, cannot be in the AIL. However, aborted
* buffers may be dirty and hence in the AIL. Therefore if we are
* aborting a buffer and we've just taken the last refernce away, we
* have to check if it is in the AIL before freeing it. We need to free
* it in this case, because an aborted transaction has already shut the
* filesystem down and this is the last chance we will have to do so.
*/
if (atomic_dec_and_test(&bip->bli_refcount)) {
if (clean)
xfs_buf_item_relse(bp);
else if (aborted) {
ASSERT(XFS_FORCED_SHUTDOWN(lip->li_mountp));
if (lip->li_flags & XFS_LI_IN_AIL) {
spin_lock(&lip->li_ailp->xa_lock);
xfs_trans_ail_delete(lip->li_ailp, lip,
SHUTDOWN_LOG_IO_ERROR);
}
xfs_buf_item_relse(bp);
}
}
if (!(flags & XFS_BLI_HOLD))
xfs_buf_relse(bp);
}
static int lustre_stop_mgc(struct super_block *sb)
{
struct lustre_sb_info *lsi = s2lsi(sb);
struct obd_device *obd;
char *niduuid = NULL, *ptr = NULL;
int i, rc = 0, len = 0;
if (!lsi)
return -ENOENT;
obd = lsi->lsi_mgc;
if (!obd)
return -ENOENT;
lsi->lsi_mgc = NULL;
mutex_lock(&mgc_start_lock);
LASSERT(atomic_read(&obd->u.cli.cl_mgc_refcount) > 0);
if (!atomic_dec_and_test(&obd->u.cli.cl_mgc_refcount)) {
/* This is not fatal, every client that stops
will call in here. */
CDEBUG(D_MOUNT, "mgc still has %d references.\n",
atomic_read(&obd->u.cli.cl_mgc_refcount));
GOTO(out, rc = -EBUSY);
}
/* The MGC has no recoverable data in any case.
* force shutdown set in umount_begin */
obd->obd_no_recov = 1;
if (obd->u.cli.cl_mgc_mgsexp) {
/* An error is not fatal, if we are unable to send the
disconnect mgs ping evictor cleans up the export */
rc = obd_disconnect(obd->u.cli.cl_mgc_mgsexp);
if (rc)
CDEBUG(D_MOUNT, "disconnect failed %d\n", rc);
}
/* Save the obdname for cleaning the nid uuids, which are
obdname_XX */
len = strlen(obd->obd_name) + 6;
OBD_ALLOC(niduuid, len);
if (niduuid) {
strcpy(niduuid, obd->obd_name);
ptr = niduuid + strlen(niduuid);
}
rc = class_manual_cleanup(obd);
if (rc)
GOTO(out, rc);
/* Clean the nid uuids */
if (!niduuid)
GOTO(out, rc = -ENOMEM);
for (i = 0; i < lsi->lsi_lmd->lmd_mgs_failnodes; i++) {
sprintf(ptr, "_%x", i);
rc = do_lcfg(LUSTRE_MGC_OBDNAME, 0, LCFG_DEL_UUID,
niduuid, NULL, NULL, NULL);
if (rc)
CERROR("del MDC UUID %s failed: rc = %d\n",
niduuid, rc);
}
out:
if (niduuid)
OBD_FREE(niduuid, len);
/* class_import_put will get rid of the additional connections */
mutex_unlock(&mgc_start_lock);
return rc;
}
/* periodic work to do:
* * purge structures when they are too old
* * send announcements
*/
static void batadv_bla_periodic_work(struct work_struct *work)
{
struct delayed_work *delayed_work;
struct batadv_priv *bat_priv;
struct batadv_priv_bla *priv_bla;
struct hlist_head *head;
struct batadv_bla_backbone_gw *backbone_gw;
struct batadv_hashtable *hash;
struct batadv_hard_iface *primary_if;
int i;
delayed_work = container_of(work, struct delayed_work, work);
priv_bla = container_of(delayed_work, struct batadv_priv_bla, work);
bat_priv = container_of(priv_bla, struct batadv_priv, bla);
primary_if = batadv_primary_if_get_selected(bat_priv);
if (!primary_if)
goto out;
batadv_bla_purge_claims(bat_priv, primary_if, 0);
batadv_bla_purge_backbone_gw(bat_priv, 0);
if (!atomic_read(&bat_priv->bridge_loop_avoidance))
goto out;
hash = bat_priv->bla.backbone_hash;
if (!hash)
goto out;
for (i = 0; i < hash->size; i++) {
head = &hash->table[i];
rcu_read_lock();
hlist_for_each_entry_rcu(backbone_gw, head, hash_entry) {
if (!batadv_compare_eth(backbone_gw->orig,
primary_if->net_dev->dev_addr))
continue;
backbone_gw->lasttime = jiffies;
batadv_bla_send_announce(bat_priv, backbone_gw);
/* request_sent is only set after creation to avoid
* problems when we are not yet known as backbone gw
* in the backbone.
*
* We can reset this now after we waited some periods
* to give bridge forward delays and bla group forming
* some grace time.
*/
if (atomic_read(&backbone_gw->request_sent) == 0)
continue;
if (!atomic_dec_and_test(&backbone_gw->wait_periods))
continue;
atomic_dec(&backbone_gw->bat_priv->bla.num_requests);
atomic_set(&backbone_gw->request_sent, 0);
}
rcu_read_unlock();
}
out:
if (primary_if)
batadv_hardif_free_ref(primary_if);
queue_delayed_work(batadv_event_workqueue, &bat_priv->bla.work,
msecs_to_jiffies(BATADV_BLA_PERIOD_LENGTH));
}
static inline void put_signal_struct(struct signal_struct *sig)
{
if (atomic_dec_and_test(&sig->sigcnt))
free_signal_struct(sig);
}
static void blk_trace_cleanup(struct blk_trace *bt)
{
blk_trace_free(bt);
if (atomic_dec_and_test(&blk_probes_ref))
blk_unregister_tracepoints();
}
void __cleanup_sighand(struct sighand_struct *sighand)
{
if (atomic_dec_and_test(&sighand->count))
kmem_cache_free(sighand_cachep, sighand);
}
void fd_device_del_locked(struct fd_device *dev)
{
if (!atomic_dec_and_test(&dev->refcnt))
return;
fd_device_del_impl(dev);
}
static __inline__ void
netlink_unlock_table(void)
{
if (atomic_dec_and_test(&nl_table_users))
wake_up(&nl_table_wait);
}
static void
put_layout_hdr_locked(struct pnfs_layout_hdr *lo)
{
if (atomic_dec_and_test(&lo->plh_refcount))
destroy_layout_hdr(lo);
}
static void c2_cq_put(struct c2_cq *cq)
{
if (atomic_dec_and_test(&cq->refcount))
wake_up(&cq->wait);
}
static void
instance_put(struct nfulnl_instance *inst)
{
if (inst && atomic_dec_and_test(&inst->use))
call_rcu_bh(&inst->rcu, nfulnl_instance_free_rcu);
}
/*
* Drop a reference to a group. Free it if it's through.
*/
void fsnotify_put_group(struct fsnotify_group *group)
{
if (atomic_dec_and_test(&group->refcnt))
fsnotify_destroy_group(group);
}
/*
* This is called to unpin the buffer associated with the buf log
* item which was previously pinned with a call to xfs_buf_item_pin().
*
* Also drop the reference to the buf item for the current transaction.
* If the XFS_BLI_STALE flag is set and we are the last reference,
* then free up the buf log item and unlock the buffer.
*
* If the remove flag is set we are called from uncommit in the
* forced-shutdown path. If that is true and the reference count on
* the log item is going to drop to zero we need to free the item's
* descriptor in the transaction.
*/
STATIC void
xfs_buf_item_unpin(
struct xfs_log_item *lip,
int remove)
{
struct xfs_buf_log_item *bip = BUF_ITEM(lip);
xfs_buf_t *bp = bip->bli_buf;
struct xfs_ail *ailp = lip->li_ailp;
int stale = bip->bli_flags & XFS_BLI_STALE;
int freed;
ASSERT(XFS_BUF_FSPRIVATE(bp, xfs_buf_log_item_t *) == bip);
ASSERT(atomic_read(&bip->bli_refcount) > 0);
trace_xfs_buf_item_unpin(bip);
freed = atomic_dec_and_test(&bip->bli_refcount);
if (atomic_dec_and_test(&bp->b_pin_count))
wake_up_all(&bp->b_waiters);
if (freed && stale) {
ASSERT(bip->bli_flags & XFS_BLI_STALE);
ASSERT(XFS_BUF_VALUSEMA(bp) <= 0);
ASSERT(!(XFS_BUF_ISDELAYWRITE(bp)));
ASSERT(XFS_BUF_ISSTALE(bp));
ASSERT(bip->bli_format.blf_flags & XFS_BLF_CANCEL);
trace_xfs_buf_item_unpin_stale(bip);
if (remove) {
/*
* If we are in a transaction context, we have to
* remove the log item from the transaction as we are
* about to release our reference to the buffer. If we
* don't, the unlock that occurs later in
* xfs_trans_uncommit() will try to reference the
* buffer which we no longer have a hold on.
*/
if (lip->li_desc)
xfs_trans_del_item(lip);
/*
* Since the transaction no longer refers to the buffer,
* the buffer should no longer refer to the transaction.
*/
XFS_BUF_SET_FSPRIVATE2(bp, NULL);
}
/*
* If we get called here because of an IO error, we may
* or may not have the item on the AIL. xfs_trans_ail_delete()
* will take care of that situation.
* xfs_trans_ail_delete() drops the AIL lock.
*/
if (bip->bli_flags & XFS_BLI_STALE_INODE) {
xfs_buf_do_callbacks(bp);
XFS_BUF_SET_FSPRIVATE(bp, NULL);
XFS_BUF_CLR_IODONE_FUNC(bp);
} else {
spin_lock(&ailp->xa_lock);
xfs_trans_ail_delete(ailp, lip, SHUTDOWN_LOG_IO_ERROR);
xfs_buf_item_relse(bp);
ASSERT(XFS_BUF_FSPRIVATE(bp, void *) == NULL);
}
xfs_buf_relse(bp);
}
void iser_conn_put(struct iser_conn *ib_conn)
{
if (atomic_dec_and_test(&ib_conn->refcount))
iser_conn_release(ib_conn);
}
void fuse_conn_put(struct fuse_conn *fc)
{
if (atomic_dec_and_test(&fc->count))
kfree(fc);
}
void skiplist_put_leaf(struct sl_leaf *leaf)
{
BUG_ON(atomic_read(&leaf->refs) == 0);
if (atomic_dec_and_test(&leaf->refs))
call_rcu(&leaf->rcu_head, sl_free_rcu);
}
static __inline__ void rt6_release(struct rt6_info *rt)
{
if (atomic_dec_and_test(&rt->rt6i_ref))
dst_free(&rt->dst);
}
/*
* The open method is always the first operation performed on the device file.
* It is provided for a driver to do any initialization in preparation for
* later operations. In most drivers, open should perform the following tasks:
* 1) Check for device-specific errors (such as device-not-ready or similar
* hardware problems).
* 2) Initialize the device if it is being opened for the first time
* 3) Update the f_op pointer, if necessary
* 4) Allocate and fill any data structure to be put in filp->private_data.
* Driver can store device context content, such as device handler,
* interface handler etc. in the private_data. We can treat the private_data as
* the bridge between file structure and lower level device object. More than
* one application processes have their own file descriptor opened for a device.
* After driver store device context data in the open method for this device,
* other file operation methods can get access to these data easily later.
*/
static int osrfx2_fp_open(struct inode *inode, struct file *file)
{
struct osrfx2 *fx2dev;
struct usb_interface *interface;
int subminor;
int retval = 0;
#if FILE_NOSHARE_READWRITE
int oflags;
#endif /* FILE_NOSHARE_READWRITE */
subminor = iminor(inode);
interface = usb_find_interface(&osrfx2_driver, subminor);
if (!interface) {
ENTRY(NULL, "can't find device for minor %d\n", subminor);
EXIT(NULL, -ENODEV, "");
return -ENODEV;
}
ENTRY(&interface->dev, "minor = %d\n", subminor);
fx2dev = usb_get_intfdata(interface);
if (!fx2dev) {
retval = -ENODEV;
goto exit;
}
#if FILE_NOSHARE_READWRITE
/*
* Serialize access to each of the bulk pipes.
*/
oflags = (file->f_flags & O_ACCMODE);
if ((oflags == O_WRONLY) || (oflags == O_RDWR)) {
if (atomic_dec_and_test( &fx2dev->bulk_write_available ) == 0) {
atomic_inc( &fx2dev->bulk_write_available );
retval = -EBUSY;
goto exit;
}
}
if ((oflags == O_RDONLY) || (oflags == O_RDWR)) {
if (atomic_dec_and_test( &fx2dev->bulk_read_available ) == 0) {
atomic_inc( &fx2dev->bulk_read_available );
if (oflags == O_RDWR)
atomic_inc( &fx2dev->bulk_write_available );
retval = -EBUSY;
goto exit;
}
}
#endif /* FILE_NOSHARE_READWRITE */
/**
* Set this device as non-seekable bcos it does not make sense for osrfx2.
* Refer to http://lwn.net/Articles/97154/ "Safe seeks" and ldd3 section 6.5.
*/
retval = nonseekable_open(inode, file);
if (0 != retval) {
goto exit;
}
/* increment our usage count for the device */
kref_get(&fx2dev->kref);
/* save our object in the file's private structure */
file->private_data = fx2dev;
exit:
EXIT(&interface->dev, retval, "");
return retval;
}
static void put_uprobe(struct uprobe *uprobe)
{
if (atomic_dec_and_test(&uprobe->ref))
kfree(uprobe);
}
static __inline__ void fq_put(struct frag_queue *fq)
{
if (atomic_dec_and_test(&fq->refcnt))
ip6_frag_destroy(fq);
}
static void xen_blkif_free(struct xen_blkif *blkif)
{
if (!atomic_dec_and_test(&blkif->refcnt))
BUG();
kmem_cache_free(xen_blkif_cachep, blkif);
}
/*
* unshare allows a process to 'unshare' part of the process
* context which was originally shared using clone. copy_*
* functions used by do_fork() cannot be used here directly
* because they modify an inactive task_struct that is being
* constructed. Here we are modifying the current, active,
* task_struct.
*/
SYSCALL_DEFINE1(unshare, unsigned long, unshare_flags)
{
int err = 0;
struct fs_struct *fs, *new_fs = NULL;
struct sighand_struct *new_sigh = NULL;
struct mm_struct *mm, *new_mm = NULL, *active_mm = NULL;
struct files_struct *fd, *new_fd = NULL;
struct nsproxy *new_nsproxy = NULL;
int do_sysvsem = 0;
check_unshare_flags(&unshare_flags);
/* Return -EINVAL for all unsupported flags */
err = -EINVAL;
if (unshare_flags & ~(CLONE_THREAD|CLONE_FS|CLONE_NEWNS|CLONE_SIGHAND|
CLONE_VM|CLONE_FILES|CLONE_SYSVSEM|
CLONE_NEWUTS|CLONE_NEWIPC|CLONE_NEWNET))
goto bad_unshare_out;
/*
* CLONE_NEWIPC must also detach from the undolist: after switching
* to a new ipc namespace, the semaphore arrays from the old
* namespace are unreachable.
*/
if (unshare_flags & (CLONE_NEWIPC|CLONE_SYSVSEM))
do_sysvsem = 1;
if ((err = unshare_thread(unshare_flags)))
goto bad_unshare_out;
if ((err = unshare_fs(unshare_flags, &new_fs)))
goto bad_unshare_cleanup_thread;
if ((err = unshare_sighand(unshare_flags, &new_sigh)))
goto bad_unshare_cleanup_fs;
if ((err = unshare_vm(unshare_flags, &new_mm)))
goto bad_unshare_cleanup_sigh;
if ((err = unshare_fd(unshare_flags, &new_fd)))
goto bad_unshare_cleanup_vm;
if ((err = unshare_nsproxy_namespaces(unshare_flags, &new_nsproxy,
new_fs)))
goto bad_unshare_cleanup_fd;
if (new_fs || new_mm || new_fd || do_sysvsem || new_nsproxy) {
if (do_sysvsem) {
/*
* CLONE_SYSVSEM is equivalent to sys_exit().
*/
exit_sem(current);
}
if (new_nsproxy) {
switch_task_namespaces(current, new_nsproxy);
new_nsproxy = NULL;
}
task_lock(current);
if (new_fs) {
fs = current->fs;
spin_lock(&fs->lock);
current->fs = new_fs;
if (--fs->users)
new_fs = NULL;
else
new_fs = fs;
spin_unlock(&fs->lock);
}
if (new_mm) {
mm = current->mm;
active_mm = current->active_mm;
current->mm = new_mm;
current->active_mm = new_mm;
activate_mm(active_mm, new_mm);
new_mm = mm;
}
if (new_fd) {
fd = current->files;
current->files = new_fd;
new_fd = fd;
}
task_unlock(current);
}
if (new_nsproxy)
put_nsproxy(new_nsproxy);
bad_unshare_cleanup_fd:
if (new_fd)
put_files_struct(new_fd);
bad_unshare_cleanup_vm:
if (new_mm)
mmput(new_mm);
bad_unshare_cleanup_sigh:
if (new_sigh)
if (atomic_dec_and_test(&new_sigh->count))
kmem_cache_free(sighand_cachep, new_sigh);
bad_unshare_cleanup_fs:
if (new_fs)
free_fs_struct(new_fs);
bad_unshare_cleanup_thread:
bad_unshare_out:
return err;
}
static int blk_trace_synthesize_old_trace(struct trace_iterator *iter)
{
struct trace_seq *s = &iter->seq;
struct blk_io_trace *t = (struct blk_io_trace *)iter->ent;
const int offset = offsetof(struct blk_io_trace, sector);
struct blk_io_trace old = {
.magic = BLK_IO_TRACE_MAGIC | BLK_IO_TRACE_VERSION,
.time = iter->ts,
};
if (!trace_seq_putmem(s, &old, offset))
return 0;
return trace_seq_putmem(s, &t->sector,
sizeof(old) - offset + t->pdu_len);
}
static enum print_line_t
blk_trace_event_print_binary(struct trace_iterator *iter, int flags)
{
return blk_trace_synthesize_old_trace(iter) ?
TRACE_TYPE_HANDLED : TRACE_TYPE_PARTIAL_LINE;
}
static enum print_line_t blk_tracer_print_line(struct trace_iterator *iter)
{
if (!(blk_tracer_flags.val & TRACE_BLK_OPT_CLASSIC))
return TRACE_TYPE_UNHANDLED;
return print_one_line(iter, true);
}
static int blk_tracer_set_flag(u32 old_flags, u32 bit, int set)
{
if (bit == TRACE_BLK_OPT_CLASSIC) {
if (set)
trace_flags &= ~TRACE_ITER_CONTEXT_INFO;
else
trace_flags |= TRACE_ITER_CONTEXT_INFO;
}
return 0;
}
static struct tracer blk_tracer __read_mostly = {
.name = "blk",
.init = blk_tracer_init,
.reset = blk_tracer_reset,
.start = blk_tracer_start,
.stop = blk_tracer_stop,
.print_header = blk_tracer_print_header,
.print_line = blk_tracer_print_line,
.flags = &blk_tracer_flags,
.set_flag = blk_tracer_set_flag,
};
static struct trace_event trace_blk_event = {
.type = TRACE_BLK,
.trace = blk_trace_event_print,
.binary = blk_trace_event_print_binary,
};
static int __init init_blk_tracer(void)
{
if (!register_ftrace_event(&trace_blk_event)) {
pr_warning("Warning: could not register block events\n");
return 1;
}
if (register_tracer(&blk_tracer) != 0) {
pr_warning("Warning: could not register the block tracer\n");
unregister_ftrace_event(&trace_blk_event);
return 1;
}
return 0;
}
device_initcall(init_blk_tracer);
static int blk_trace_remove_queue(struct request_queue *q)
{
struct blk_trace *bt;
bt = xchg(&q->blk_trace, NULL);
if (bt == NULL)
return -EINVAL;
if (atomic_dec_and_test(&blk_probes_ref))
blk_unregister_tracepoints();
blk_trace_free(bt);
return 0;
}
static int blk_trace_setup_queue(struct request_queue *q,
struct block_device *bdev)
{
struct blk_trace *old_bt, *bt = NULL;
int ret = -ENOMEM;
bt = kzalloc(sizeof(*bt), GFP_KERNEL);
if (!bt)
return -ENOMEM;
bt->msg_data = __alloc_percpu(BLK_TN_MAX_MSG, __alignof__(char));
if (!bt->msg_data)
goto free_bt;
bt->dev = bdev->bd_dev;
bt->act_mask = (u16)-1;
blk_trace_setup_lba(bt, bdev);
old_bt = xchg(&q->blk_trace, bt);
if (old_bt != NULL) {
(void)xchg(&q->blk_trace, old_bt);
ret = -EBUSY;
goto free_bt;
}
if (atomic_inc_return(&blk_probes_ref) == 1)
blk_register_tracepoints();
return 0;
free_bt:
blk_trace_free(bt);
return ret;
}
static ssize_t sysfs_blk_trace_attr_show(struct device *dev,
struct device_attribute *attr,
char *buf);
static ssize_t sysfs_blk_trace_attr_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count);
#define BLK_TRACE_DEVICE_ATTR(_name) \
DEVICE_ATTR(_name, S_IRUGO | S_IWUSR, \
sysfs_blk_trace_attr_show, \
sysfs_blk_trace_attr_store)
static BLK_TRACE_DEVICE_ATTR(enable);
static BLK_TRACE_DEVICE_ATTR(act_mask);
static BLK_TRACE_DEVICE_ATTR(pid);
static BLK_TRACE_DEVICE_ATTR(start_lba);
static BLK_TRACE_DEVICE_ATTR(end_lba);
static struct attribute *blk_trace_attrs[] = {
&dev_attr_enable.attr,
&dev_attr_act_mask.attr,
&dev_attr_pid.attr,
&dev_attr_start_lba.attr,
&dev_attr_end_lba.attr,
NULL
};
struct attribute_group blk_trace_attr_group = {
.name = "trace",
.attrs = blk_trace_attrs,
};
static const struct {
int mask;
const char *str;
} mask_maps[] = {
{ BLK_TC_READ, "read" },
{ BLK_TC_WRITE, "write" },
{ BLK_TC_BARRIER, "barrier" },
{ BLK_TC_SYNC, "sync" },
{ BLK_TC_QUEUE, "queue" },
{ BLK_TC_REQUEUE, "requeue" },
{ BLK_TC_ISSUE, "issue" },
{ BLK_TC_COMPLETE, "complete" },
{ BLK_TC_FS, "fs" },
{ BLK_TC_PC, "pc" },
{ BLK_TC_AHEAD, "ahead" },
{ BLK_TC_META, "meta" },
{ BLK_TC_DISCARD, "discard" },
{ BLK_TC_DRV_DATA, "drv_data" },
};
static int blk_trace_str2mask(const char *str)
{
int i;
int mask = 0;
char *buf, *s, *token;
buf = kstrdup(str, GFP_KERNEL);
if (buf == NULL)
return -ENOMEM;
s = strstrip(buf);
while (1) {
token = strsep(&s, ",");
if (token == NULL)
break;
if (*token == '\0')
continue;
for (i = 0; i < ARRAY_SIZE(mask_maps); i++) {
if (strcasecmp(token, mask_maps[i].str) == 0) {
mask |= mask_maps[i].mask;
break;
}
}
if (i == ARRAY_SIZE(mask_maps)) {
mask = -EINVAL;
break;
}
}
kfree(buf);
return mask;
}
static ssize_t blk_trace_mask2str(char *buf, int mask)
{
int i;
char *p = buf;
for (i = 0; i < ARRAY_SIZE(mask_maps); i++) {
if (mask & mask_maps[i].mask) {
p += sprintf(p, "%s%s",
(p == buf) ? "" : ",", mask_maps[i].str);
}
}
*p++ = '\n';
return p - buf;
}
static struct request_queue *blk_trace_get_queue(struct block_device *bdev)
{
if (bdev->bd_disk == NULL)
return NULL;
return bdev_get_queue(bdev);
}
static ssize_t sysfs_blk_trace_attr_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct hd_struct *p = dev_to_part(dev);
struct request_queue *q;
struct block_device *bdev;
ssize_t ret = -ENXIO;
lock_kernel();
bdev = bdget(part_devt(p));
if (bdev == NULL)
goto out_unlock_kernel;
q = blk_trace_get_queue(bdev);
if (q == NULL)
goto out_bdput;
mutex_lock(&bdev->bd_mutex);
if (attr == &dev_attr_enable) {
ret = sprintf(buf, "%u\n", !!q->blk_trace);
goto out_unlock_bdev;
}
if (q->blk_trace == NULL)
ret = sprintf(buf, "disabled\n");
else if (attr == &dev_attr_act_mask)
ret = blk_trace_mask2str(buf, q->blk_trace->act_mask);
else if (attr == &dev_attr_pid)
ret = sprintf(buf, "%u\n", q->blk_trace->pid);
else if (attr == &dev_attr_start_lba)
ret = sprintf(buf, "%llu\n", q->blk_trace->start_lba);
else if (attr == &dev_attr_end_lba)
ret = sprintf(buf, "%llu\n", q->blk_trace->end_lba);
out_unlock_bdev:
mutex_unlock(&bdev->bd_mutex);
out_bdput:
bdput(bdev);
out_unlock_kernel:
unlock_kernel();
return ret;
}
static ssize_t sysfs_blk_trace_attr_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct block_device *bdev;
struct request_queue *q;
struct hd_struct *p;
u64 value;
ssize_t ret = -EINVAL;
if (count == 0)
goto out;
if (attr == &dev_attr_act_mask) {
if (sscanf(buf, "%llx", &value) != 1) {
ret = blk_trace_str2mask(buf);
if (ret < 0)
goto out;
value = ret;
}
} else if (sscanf(buf, "%llu", &value) != 1)
goto out;
ret = -ENXIO;
lock_kernel();
p = dev_to_part(dev);
bdev = bdget(part_devt(p));
if (bdev == NULL)
goto out_unlock_kernel;
q = blk_trace_get_queue(bdev);
if (q == NULL)
goto out_bdput;
mutex_lock(&bdev->bd_mutex);
if (attr == &dev_attr_enable) {
if (value)
ret = blk_trace_setup_queue(q, bdev);
else
ret = blk_trace_remove_queue(q);
goto out_unlock_bdev;
}
ret = 0;
if (q->blk_trace == NULL)
ret = blk_trace_setup_queue(q, bdev);
if (ret == 0) {
if (attr == &dev_attr_act_mask)
q->blk_trace->act_mask = value;
else if (attr == &dev_attr_pid)
q->blk_trace->pid = value;
else if (attr == &dev_attr_start_lba)
q->blk_trace->start_lba = value;
else if (attr == &dev_attr_end_lba)
q->blk_trace->end_lba = value;
}
out_unlock_bdev:
mutex_unlock(&bdev->bd_mutex);
out_bdput:
bdput(bdev);
out_unlock_kernel:
unlock_kernel();
out:
return ret ? ret : count;
}
int blk_trace_init_sysfs(struct device *dev)
{
return sysfs_create_group(&dev->kobj, &blk_trace_attr_group);
}
void blk_trace_remove_sysfs(struct device *dev)
{
sysfs_remove_group(&dev->kobj, &blk_trace_attr_group);
}
/** Decrement reference count, freeing if zero.
*
* @param info vnet (OK if null)
*/
void Vnet_decref(Vnet *info) {
if(!info) return;
if(atomic_dec_and_test(&info->refcount)) {
deallocate(info);
}
}
/*!
* @fn ssize_t output_Read(struct file *filp,
* char *buf,
* size_t count,
* loff_t *f_pos,
* BUFFER_DESC kernel_buf)
*
* @brief Return a sample buffer to user-mode. If not full or flush, wait
*
* @param *filp a file pointer
* @param *buf a sampling buffer
* @param count size of the user's buffer
* @param f_pos file pointer (current offset in bytes)
* @param kernel_buf the kernel output buffer structure
*
* @return number of bytes read. zero indicates end of file. Neg means error
*
* Place no more than count bytes into the user's buffer.
* Block if unavailable on "BUFFER_DESC_queue(buf)"
*
* <I>Special Notes:</I>
*
*/
static ssize_t
output_Read (
struct file *filp,
char *buf,
size_t count,
loff_t *f_pos,
BUFFER_DESC kernel_buf
)
{
ssize_t to_copy;
ssize_t uncopied;
OUTPUT outbuf = &BUFFER_DESC_outbuf(kernel_buf);
U32 cur_buf, i;
/* Buffer is filled by output_fill_modules. */
cur_buf = OUTPUT_current_buffer(outbuf);
for (i=0; i<OUTPUT_NUM_BUFFERS; i++) { //iterate through all buffers
cur_buf++;
if (cur_buf >= OUTPUT_NUM_BUFFERS) { cur_buf = 0; } //circularly
if ((to_copy = OUTPUT_buffer_full(outbuf, cur_buf))) {
break;
}
}
SEP_PRINT_DEBUG("buffer %d has %d bytes ready\n", (S32)cur_buf, (S32)to_copy);
if (!flush && to_copy == 0) {
#if defined(CONFIG_PREEMPT_RT)
do {
unsigned long delay;
delay = msecs_to_jiffies(1000);
wait_event_interruptible_timeout(BUFFER_DESC_queue(kernel_buf),
flush||OUTPUT_buffer_full(outbuf, cur_buf), delay);
} while (!(flush||OUTPUT_buffer_full(outbuf, cur_buf)));
#else
if (wait_event_interruptible(BUFFER_DESC_queue(kernel_buf),
flush||OUTPUT_buffer_full(outbuf, cur_buf))) {
return OS_RESTART_SYSCALL;
}
#endif
SEP_PRINT_DEBUG("Get to copy\n", (S32)cur_buf);
to_copy = OUTPUT_buffer_full(outbuf, cur_buf);
SEP_PRINT_DEBUG("output_Read awakened, buffer %d has %d bytes\n",cur_buf, (int)to_copy );
}
/* Ensure that the user's buffer is large enough */
if (to_copy > count) {
SEP_PRINT_DEBUG("user buffer is too small\n");
return OS_NO_MEM;
}
/* Copy data to user space. Note that we use cur_buf as the source */
if (abnormal_terminate == 0) {
uncopied = copy_to_user(buf,
OUTPUT_buffer(outbuf, cur_buf),
to_copy);
/* Mark the buffer empty */
OUTPUT_buffer_full(outbuf, cur_buf) = 0;
*f_pos += to_copy-uncopied;
if (uncopied) {
SEP_PRINT_DEBUG("only copied %d of %lld bytes of module records\n",
(S32)to_copy, (long long)uncopied);
return (to_copy - uncopied);
}
}
else {
to_copy = 0;
SEP_PRINT_DEBUG("to copy set to 0\n");
}
// At end-of-file, decrement the count of active buffer writers
if (to_copy == 0) {
DRV_BOOL flush_val = atomic_dec_and_test(&flush_writers);
SEP_PRINT_DEBUG("output_Read decremented flush_writers\n");
if (flush_val == TRUE) {
wake_up_interruptible_sync(&flush_queue);
}
}
return to_copy;
}
void llog_handle_put(struct llog_handle *loghandle)
{
LASSERT(atomic_read(&loghandle->lgh_refcount) > 0);
if (atomic_dec_and_test(&loghandle->lgh_refcount))
llog_free_handle(loghandle);
}
/* free a backbone gw */
static void
batadv_backbone_gw_free_ref(struct batadv_bla_backbone_gw *backbone_gw)
{
if (atomic_dec_and_test(&backbone_gw->refcount))
kfree_rcu(backbone_gw, rcu);
}
static void afs_dec_cells_outstanding(struct afs_net *net)
{
if (atomic_dec_and_test(&net->cells_outstanding))
wake_up_var(&net->cells_outstanding);
}
/* free a claim, call claim_free_rcu if its the last reference */
static void batadv_claim_free_ref(struct batadv_bla_claim *claim)
{
if (atomic_dec_and_test(&claim->refcount))
call_rcu(&claim->rcu, batadv_claim_free_rcu);
}
/*
* This is called to unpin the buffer associated with the buf log
* item which was previously pinned with a call to xfs_buf_item_pin().
*
* Also drop the reference to the buf item for the current transaction.
* If the XFS_BLI_STALE flag is set and we are the last reference,
* then free up the buf log item and unlock the buffer.
*
* If the remove flag is set we are called from uncommit in the
* forced-shutdown path. If that is true and the reference count on
* the log item is going to drop to zero we need to free the item's
* descriptor in the transaction.
*/
STATIC void
xfs_buf_item_unpin(
struct xfs_log_item *lip,
int remove)
{
struct xfs_buf_log_item *bip = BUF_ITEM(lip);
xfs_buf_t *bp = bip->bli_buf;
struct xfs_ail *ailp = lip->li_ailp;
int stale = bip->bli_flags & XFS_BLI_STALE;
int freed;
ASSERT(bp->b_fspriv == bip);
ASSERT(atomic_read(&bip->bli_refcount) > 0);
trace_xfs_buf_item_unpin(bip);
freed = atomic_dec_and_test(&bip->bli_refcount);
if (atomic_dec_and_test(&bp->b_pin_count))
wake_up_all(&bp->b_waiters);
if (freed && stale) {
ASSERT(bip->bli_flags & XFS_BLI_STALE);
ASSERT(xfs_buf_islocked(bp));
ASSERT(XFS_BUF_ISSTALE(bp));
ASSERT(bip->__bli_format.blf_flags & XFS_BLF_CANCEL);
trace_xfs_buf_item_unpin_stale(bip);
if (remove) {
/*
* If we are in a transaction context, we have to
* remove the log item from the transaction as we are
* about to release our reference to the buffer. If we
* don't, the unlock that occurs later in
* xfs_trans_uncommit() will try to reference the
* buffer which we no longer have a hold on.
*/
if (lip->li_desc)
xfs_trans_del_item(lip);
/*
* Since the transaction no longer refers to the buffer,
* the buffer should no longer refer to the transaction.
*/
bp->b_transp = NULL;
}
/*
* If we get called here because of an IO error, we may
* or may not have the item on the AIL. xfs_trans_ail_delete()
* will take care of that situation.
* xfs_trans_ail_delete() drops the AIL lock.
*/
if (bip->bli_flags & XFS_BLI_STALE_INODE) {
xfs_buf_do_callbacks(bp);
bp->b_fspriv = NULL;
bp->b_iodone = NULL;
} else {
spin_lock(&ailp->xa_lock);
xfs_trans_ail_delete(ailp, lip, SHUTDOWN_LOG_IO_ERROR);
xfs_buf_item_relse(bp);
ASSERT(bp->b_fspriv == NULL);
}
xfs_buf_relse(bp);
} else if (freed && remove) {
/*
* There are currently two references to the buffer - the active
* LRU reference and the buf log item. What we are about to do
* here - simulate a failed IO completion - requires 3
* references.
*
* The LRU reference is removed by the xfs_buf_stale() call. The
* buf item reference is removed by the xfs_buf_iodone()
* callback that is run by xfs_buf_do_callbacks() during ioend
* processing (via the bp->b_iodone callback), and then finally
* the ioend processing will drop the IO reference if the buffer
* is marked XBF_ASYNC.
*
* Hence we need to take an additional reference here so that IO
* completion processing doesn't free the buffer prematurely.
*/
xfs_buf_lock(bp);
xfs_buf_hold(bp);
bp->b_flags |= XBF_ASYNC;
xfs_buf_ioerror(bp, -EIO);
XFS_BUF_UNDONE(bp);
xfs_buf_stale(bp);
xfs_buf_ioend(bp);
}
}