From d2ccde1c8e90d38cee87a1b0309ad2827f3fd30d Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Mon, 11 Dec 2023 02:45:28 +0000
Subject: [PATCH] add boot partition size
---
kernel/include/linux/pipe_fs_i.h | 150 +++++++++++++++++++++++++++++++++++++------------
1 files changed, 113 insertions(+), 37 deletions(-)
diff --git a/kernel/include/linux/pipe_fs_i.h b/kernel/include/linux/pipe_fs_i.h
index 7897a3c..5d2705f 100644
--- a/kernel/include/linux/pipe_fs_i.h
+++ b/kernel/include/linux/pipe_fs_i.h
@@ -8,6 +8,11 @@
#define PIPE_BUF_FLAG_ATOMIC 0x02 /* was atomically mapped */
#define PIPE_BUF_FLAG_GIFT 0x04 /* page is a gift */
#define PIPE_BUF_FLAG_PACKET 0x08 /* read() as a packet */
+#define PIPE_BUF_FLAG_CAN_MERGE 0x10 /* can merge buffers */
+#define PIPE_BUF_FLAG_WHOLE 0x20 /* read() must return entire buffer or error */
+#ifdef CONFIG_WATCH_QUEUE
+#define PIPE_BUF_FLAG_LOSS 0x40 /* Message loss happened after this buffer */
+#endif
/**
* struct pipe_buffer - a linux kernel pipe buffer
@@ -29,30 +34,40 @@
/**
* struct pipe_inode_info - a linux kernel pipe
* @mutex: mutex protecting the whole thing
- * @wait: reader/writer wait point in case of empty/full pipe
- * @nrbufs: the number of non-empty pipe buffers in this pipe
- * @buffers: total number of buffers (should be a power of 2)
- * @curbuf: the current pipe buffer entry
+ * @rd_wait: reader wait point in case of empty pipe
+ * @wr_wait: writer wait point in case of full pipe
+ * @head: The point of buffer production
+ * @tail: The point of buffer consumption
+ * @note_loss: The next read() should insert a data-lost message
+ * @max_usage: The maximum number of slots that may be used in the ring
+ * @ring_size: total number of buffers (should be a power of 2)
+ * @nr_accounted: The amount this pipe accounts for in user->pipe_bufs
* @tmp_page: cached released page
* @readers: number of current readers of this pipe
* @writers: number of current writers of this pipe
* @files: number of struct file referring this pipe (protected by ->i_lock)
- * @waiting_writers: number of writers blocked waiting for room
* @r_counter: reader counter
* @w_counter: writer counter
* @fasync_readers: reader side fasync
* @fasync_writers: writer side fasync
* @bufs: the circular array of pipe buffers
* @user: the user who created this pipe
+ * @watch_queue: If this pipe is a watch_queue, this is the stuff for that
**/
struct pipe_inode_info {
struct mutex mutex;
- wait_queue_head_t wait;
- unsigned int nrbufs, curbuf, buffers;
+ wait_queue_head_t rd_wait, wr_wait;
+ unsigned int head;
+ unsigned int tail;
+ unsigned int max_usage;
+ unsigned int ring_size;
+#ifdef CONFIG_WATCH_QUEUE
+ bool note_loss;
+#endif
+ unsigned int nr_accounted;
unsigned int readers;
unsigned int writers;
unsigned int files;
- unsigned int waiting_writers;
unsigned int r_counter;
unsigned int w_counter;
struct page *tmp_page;
@@ -60,32 +75,28 @@
struct fasync_struct *fasync_writers;
struct pipe_buffer *bufs;
struct user_struct *user;
+#ifdef CONFIG_WATCH_QUEUE
+ struct watch_queue *watch_queue;
+#endif
};
/*
* Note on the nesting of these functions:
*
* ->confirm()
- * ->steal()
+ * ->try_steal()
*
- * That is, ->steal() must be called on a confirmed buffer.
- * See below for the meaning of each operation. Also see kerneldoc
- * in fs/pipe.c for the pipe and generic variants of these hooks.
+ * That is, ->try_steal() must be called on a confirmed buffer. See below for
+ * the meaning of each operation. Also see the kerneldoc in fs/pipe.c for the
+ * pipe and generic variants of these hooks.
*/
struct pipe_buf_operations {
- /*
- * This is set to 1, if the generic pipe read/write may coalesce
- * data into an existing buffer. If this is set to 0, a new pipe
- * page segment is always used for new data.
- */
- int can_merge;
-
/*
* ->confirm() verifies that the data in the pipe buffer is there
* and that the contents are good. If the pages in the pipe belong
* to a file system, we may need to wait for IO completion in this
* hook. Returns 0 for good, or a negative error value in case of
- * error.
+ * error. If not present all pages are considered good.
*/
int (*confirm)(struct pipe_inode_info *, struct pipe_buffer *);
@@ -97,19 +108,71 @@
/*
* Attempt to take ownership of the pipe buffer and its contents.
- * ->steal() returns 0 for success, in which case the contents
- * of the pipe (the buf->page) is locked and now completely owned
- * by the caller. The page may then be transferred to a different
- * mapping, the most often used case is insertion into different
- * file address space cache.
+ * ->try_steal() returns %true for success, in which case the contents
+ * of the pipe (the buf->page) is locked and now completely owned by the
+ * caller. The page may then be transferred to a different mapping, the
+ * most often used case is insertion into different file address space
+ * cache.
*/
- int (*steal)(struct pipe_inode_info *, struct pipe_buffer *);
+ bool (*try_steal)(struct pipe_inode_info *, struct pipe_buffer *);
/*
* Get a reference to the pipe buffer.
*/
bool (*get)(struct pipe_inode_info *, struct pipe_buffer *);
};
+
+/**
+ * pipe_empty - Return true if the pipe is empty
+ * @head: The pipe ring head pointer
+ * @tail: The pipe ring tail pointer
+ */
+static inline bool pipe_empty(unsigned int head, unsigned int tail)
+{
+ return head == tail;
+}
+
+/**
+ * pipe_occupancy - Return number of slots used in the pipe
+ * @head: The pipe ring head pointer
+ * @tail: The pipe ring tail pointer
+ */
+static inline unsigned int pipe_occupancy(unsigned int head, unsigned int tail)
+{
+ return head - tail;
+}
+
+/**
+ * pipe_full - Return true if the pipe is full
+ * @head: The pipe ring head pointer
+ * @tail: The pipe ring tail pointer
+ * @limit: The maximum amount of slots available.
+ */
+static inline bool pipe_full(unsigned int head, unsigned int tail,
+ unsigned int limit)
+{
+ return pipe_occupancy(head, tail) >= limit;
+}
+
+/**
+ * pipe_space_for_user - Return number of slots available to userspace
+ * @head: The pipe ring head pointer
+ * @tail: The pipe ring tail pointer
+ * @pipe: The pipe info structure
+ */
+static inline unsigned int pipe_space_for_user(unsigned int head, unsigned int tail,
+ struct pipe_inode_info *pipe)
+{
+ unsigned int p_occupancy, p_space;
+
+ p_occupancy = pipe_occupancy(head, tail);
+ if (p_occupancy >= pipe->max_usage)
+ return 0;
+ p_space = pipe->ring_size - p_occupancy;
+ if (p_space > pipe->max_usage)
+ p_space = pipe->max_usage;
+ return p_space;
+}
/**
* pipe_buf_get - get a reference to a pipe_buffer
@@ -146,18 +209,22 @@
static inline int pipe_buf_confirm(struct pipe_inode_info *pipe,
struct pipe_buffer *buf)
{
+ if (!buf->ops->confirm)
+ return 0;
return buf->ops->confirm(pipe, buf);
}
/**
- * pipe_buf_steal - attempt to take ownership of a pipe_buffer
+ * pipe_buf_try_steal - attempt to take ownership of a pipe_buffer
* @pipe: the pipe that the buffer belongs to
* @buf: the buffer to attempt to steal
*/
-static inline int pipe_buf_steal(struct pipe_inode_info *pipe,
- struct pipe_buffer *buf)
+static inline bool pipe_buf_try_steal(struct pipe_inode_info *pipe,
+ struct pipe_buffer *buf)
{
- return buf->ops->steal(pipe, buf);
+ if (!buf->ops->try_steal)
+ return false;
+ return buf->ops->try_steal(pipe, buf);
}
/* Differs from PIPE_BUF in that PIPE_SIZE is the length of the actual
@@ -173,25 +240,34 @@
extern unsigned long pipe_user_pages_hard;
extern unsigned long pipe_user_pages_soft;
-/* Drop the inode semaphore and wait for a pipe event, atomically */
-void pipe_wait(struct pipe_inode_info *pipe);
+/* Wait for a pipe to be readable/writable while dropping the pipe lock */
+void pipe_wait_readable(struct pipe_inode_info *);
+void pipe_wait_writable(struct pipe_inode_info *);
struct pipe_inode_info *alloc_pipe_info(void);
void free_pipe_info(struct pipe_inode_info *);
/* Generic pipe buffer ops functions */
bool generic_pipe_buf_get(struct pipe_inode_info *, struct pipe_buffer *);
-int generic_pipe_buf_confirm(struct pipe_inode_info *, struct pipe_buffer *);
-int generic_pipe_buf_steal(struct pipe_inode_info *, struct pipe_buffer *);
-int generic_pipe_buf_nosteal(struct pipe_inode_info *, struct pipe_buffer *);
+bool generic_pipe_buf_try_steal(struct pipe_inode_info *, struct pipe_buffer *);
void generic_pipe_buf_release(struct pipe_inode_info *, struct pipe_buffer *);
-void pipe_buf_mark_unmergeable(struct pipe_buffer *buf);
extern const struct pipe_buf_operations nosteal_pipe_buf_ops;
+#ifdef CONFIG_WATCH_QUEUE
+unsigned long account_pipe_buffers(struct user_struct *user,
+ unsigned long old, unsigned long new);
+bool too_many_pipe_buffers_soft(unsigned long user_bufs);
+bool too_many_pipe_buffers_hard(unsigned long user_bufs);
+bool pipe_is_unprivileged_user(void);
+#endif
+
/* for F_SETPIPE_SZ and F_GETPIPE_SZ */
+#ifdef CONFIG_WATCH_QUEUE
+int pipe_resize_ring(struct pipe_inode_info *pipe, unsigned int nr_slots);
+#endif
long pipe_fcntl(struct file *, unsigned int, unsigned long arg);
-struct pipe_inode_info *get_pipe_info(struct file *file);
+struct pipe_inode_info *get_pipe_info(struct file *file, bool for_splice);
int create_pipe_files(struct file **, int);
unsigned int round_pipe_size(unsigned long size);
--
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