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-rw-r--r--Documentation/DocBook/kernel-api.tmpl16
-rw-r--r--kernel/relay.c36
2 files changed, 38 insertions, 14 deletions
diff --git a/Documentation/DocBook/kernel-api.tmpl b/Documentation/DocBook/kernel-api.tmpl
index f8fe882e33d..ea6f375475b 100644
--- a/Documentation/DocBook/kernel-api.tmpl
+++ b/Documentation/DocBook/kernel-api.tmpl
@@ -202,6 +202,22 @@ X!Ilib/string.c
202 </sect1> 202 </sect1>
203 </chapter> 203 </chapter>
204 204
205 <chapter id="relayfs">
206 <title>relay interface support</title>
207
208 <para>
209 Relay interface support
210 is designed to provide an efficient mechanism for tools and
211 facilities to relay large amounts of data from kernel space to
212 user space.
213 </para>
214
215 <sect1><title>relay interface</title>
216!Ekernel/relay.c
217!Ikernel/relay.c
218 </sect1>
219 </chapter>
220
205 <chapter id="vfs"> 221 <chapter id="vfs">
206 <title>The Linux VFS</title> 222 <title>The Linux VFS</title>
207 <sect1><title>The Filesystem types</title> 223 <sect1><title>The Filesystem types</title>
diff --git a/kernel/relay.c b/kernel/relay.c
index 85786ff2a4f..1d63ecddfa7 100644
--- a/kernel/relay.c
+++ b/kernel/relay.c
@@ -95,7 +95,7 @@ int relay_mmap_buf(struct rchan_buf *buf, struct vm_area_struct *vma)
95 * @buf: the buffer struct 95 * @buf: the buffer struct
96 * @size: total size of the buffer 96 * @size: total size of the buffer
97 * 97 *
98 * Returns a pointer to the resulting buffer, NULL if unsuccessful. The 98 * Returns a pointer to the resulting buffer, %NULL if unsuccessful. The
99 * passed in size will get page aligned, if it isn't already. 99 * passed in size will get page aligned, if it isn't already.
100 */ 100 */
101static void *relay_alloc_buf(struct rchan_buf *buf, size_t *size) 101static void *relay_alloc_buf(struct rchan_buf *buf, size_t *size)
@@ -132,10 +132,9 @@ depopulate:
132 132
133/** 133/**
134 * relay_create_buf - allocate and initialize a channel buffer 134 * relay_create_buf - allocate and initialize a channel buffer
135 * @alloc_size: size of the buffer to allocate 135 * @chan: the relay channel
136 * @n_subbufs: number of sub-buffers in the channel
137 * 136 *
138 * Returns channel buffer if successful, NULL otherwise 137 * Returns channel buffer if successful, %NULL otherwise.
139 */ 138 */
140struct rchan_buf *relay_create_buf(struct rchan *chan) 139struct rchan_buf *relay_create_buf(struct rchan *chan)
141{ 140{
@@ -163,6 +162,7 @@ free_buf:
163 162
164/** 163/**
165 * relay_destroy_channel - free the channel struct 164 * relay_destroy_channel - free the channel struct
165 * @kref: target kernel reference that contains the relay channel
166 * 166 *
167 * Should only be called from kref_put(). 167 * Should only be called from kref_put().
168 */ 168 */
@@ -194,6 +194,7 @@ void relay_destroy_buf(struct rchan_buf *buf)
194 194
195/** 195/**
196 * relay_remove_buf - remove a channel buffer 196 * relay_remove_buf - remove a channel buffer
197 * @kref: target kernel reference that contains the relay buffer
197 * 198 *
198 * Removes the file from the fileystem, which also frees the 199 * Removes the file from the fileystem, which also frees the
199 * rchan_buf_struct and the channel buffer. Should only be called from 200 * rchan_buf_struct and the channel buffer. Should only be called from
@@ -374,7 +375,7 @@ void relay_reset(struct rchan *chan)
374} 375}
375EXPORT_SYMBOL_GPL(relay_reset); 376EXPORT_SYMBOL_GPL(relay_reset);
376 377
377/** 378/*
378 * relay_open_buf - create a new relay channel buffer 379 * relay_open_buf - create a new relay channel buffer
379 * 380 *
380 * Internal - used by relay_open(). 381 * Internal - used by relay_open().
@@ -448,12 +449,12 @@ static inline void setup_callbacks(struct rchan *chan,
448/** 449/**
449 * relay_open - create a new relay channel 450 * relay_open - create a new relay channel
450 * @base_filename: base name of files to create 451 * @base_filename: base name of files to create
451 * @parent: dentry of parent directory, NULL for root directory 452 * @parent: dentry of parent directory, %NULL for root directory
452 * @subbuf_size: size of sub-buffers 453 * @subbuf_size: size of sub-buffers
453 * @n_subbufs: number of sub-buffers 454 * @n_subbufs: number of sub-buffers
454 * @cb: client callback functions 455 * @cb: client callback functions
455 * 456 *
456 * Returns channel pointer if successful, NULL otherwise. 457 * Returns channel pointer if successful, %NULL otherwise.
457 * 458 *
458 * Creates a channel buffer for each cpu using the sizes and 459 * Creates a channel buffer for each cpu using the sizes and
459 * attributes specified. The created channel buffer files 460 * attributes specified. The created channel buffer files
@@ -585,7 +586,7 @@ EXPORT_SYMBOL_GPL(relay_switch_subbuf);
585 * subbufs_consumed should be the number of sub-buffers newly consumed, 586 * subbufs_consumed should be the number of sub-buffers newly consumed,
586 * not the total consumed. 587 * not the total consumed.
587 * 588 *
588 * NOTE: kernel clients don't need to call this function if the channel 589 * NOTE: Kernel clients don't need to call this function if the channel
589 * mode is 'overwrite'. 590 * mode is 'overwrite'.
590 */ 591 */
591void relay_subbufs_consumed(struct rchan *chan, 592void relay_subbufs_consumed(struct rchan *chan,
@@ -641,7 +642,7 @@ EXPORT_SYMBOL_GPL(relay_close);
641 * relay_flush - close the channel 642 * relay_flush - close the channel
642 * @chan: the channel 643 * @chan: the channel
643 * 644 *
644 * Flushes all channel buffers i.e. forces buffer switch. 645 * Flushes all channel buffers, i.e. forces buffer switch.
645 */ 646 */
646void relay_flush(struct rchan *chan) 647void relay_flush(struct rchan *chan)
647{ 648{
@@ -729,7 +730,7 @@ static int relay_file_release(struct inode *inode, struct file *filp)
729 return 0; 730 return 0;
730} 731}
731 732
732/** 733/*
733 * relay_file_read_consume - update the consumed count for the buffer 734 * relay_file_read_consume - update the consumed count for the buffer
734 */ 735 */
735static void relay_file_read_consume(struct rchan_buf *buf, 736static void relay_file_read_consume(struct rchan_buf *buf,
@@ -756,7 +757,7 @@ static void relay_file_read_consume(struct rchan_buf *buf,
756 } 757 }
757} 758}
758 759
759/** 760/*
760 * relay_file_read_avail - boolean, are there unconsumed bytes available? 761 * relay_file_read_avail - boolean, are there unconsumed bytes available?
761 */ 762 */
762static int relay_file_read_avail(struct rchan_buf *buf, size_t read_pos) 763static int relay_file_read_avail(struct rchan_buf *buf, size_t read_pos)
@@ -793,6 +794,8 @@ static int relay_file_read_avail(struct rchan_buf *buf, size_t read_pos)
793 794
794/** 795/**
795 * relay_file_read_subbuf_avail - return bytes available in sub-buffer 796 * relay_file_read_subbuf_avail - return bytes available in sub-buffer
797 * @read_pos: file read position
798 * @buf: relay channel buffer
796 */ 799 */
797static size_t relay_file_read_subbuf_avail(size_t read_pos, 800static size_t relay_file_read_subbuf_avail(size_t read_pos,
798 struct rchan_buf *buf) 801 struct rchan_buf *buf)
@@ -818,6 +821,8 @@ static size_t relay_file_read_subbuf_avail(size_t read_pos,
818 821
819/** 822/**
820 * relay_file_read_start_pos - find the first available byte to read 823 * relay_file_read_start_pos - find the first available byte to read
824 * @read_pos: file read position
825 * @buf: relay channel buffer
821 * 826 *
822 * If the read_pos is in the middle of padding, return the 827 * If the read_pos is in the middle of padding, return the
823 * position of the first actually available byte, otherwise 828 * position of the first actually available byte, otherwise
@@ -844,6 +849,9 @@ static size_t relay_file_read_start_pos(size_t read_pos,
844 849
845/** 850/**
846 * relay_file_read_end_pos - return the new read position 851 * relay_file_read_end_pos - return the new read position
852 * @read_pos: file read position
853 * @buf: relay channel buffer
854 * @count: number of bytes to be read
847 */ 855 */
848static size_t relay_file_read_end_pos(struct rchan_buf *buf, 856static size_t relay_file_read_end_pos(struct rchan_buf *buf,
849 size_t read_pos, 857 size_t read_pos,
@@ -865,7 +873,7 @@ static size_t relay_file_read_end_pos(struct rchan_buf *buf,
865 return end_pos; 873 return end_pos;
866} 874}
867 875
868/** 876/*
869 * subbuf_read_actor - read up to one subbuf's worth of data 877 * subbuf_read_actor - read up to one subbuf's worth of data
870 */ 878 */
871static int subbuf_read_actor(size_t read_start, 879static int subbuf_read_actor(size_t read_start,
@@ -890,7 +898,7 @@ static int subbuf_read_actor(size_t read_start,
890 return ret; 898 return ret;
891} 899}
892 900
893/** 901/*
894 * subbuf_send_actor - send up to one subbuf's worth of data 902 * subbuf_send_actor - send up to one subbuf's worth of data
895 */ 903 */
896static int subbuf_send_actor(size_t read_start, 904static int subbuf_send_actor(size_t read_start,
@@ -933,7 +941,7 @@ typedef int (*subbuf_actor_t) (size_t read_start,
933 read_descriptor_t *desc, 941 read_descriptor_t *desc,
934 read_actor_t actor); 942 read_actor_t actor);
935 943
936/** 944/*
937 * relay_file_read_subbufs - read count bytes, bridging subbuf boundaries 945 * relay_file_read_subbufs - read count bytes, bridging subbuf boundaries
938 */ 946 */
939static inline ssize_t relay_file_read_subbufs(struct file *filp, 947static inline ssize_t relay_file_read_subbufs(struct file *filp,