Skip to content

Commit

Permalink
relay: remove unused buf_mapped and buf_unmapped callbacks
Browse files Browse the repository at this point in the history
Patch series "relay: cleanup and const callbacks", v2.

None of the relay users require the use of mutable structs for callbacks,
however the relay code does.  Instead of assigning default callbacks when
there is none, add callback wrappers to conditionally call the client
callbacks if available, and fall back to default behaviour (typically
no-op) otherwise.

This lets all relay users make their struct rchan_callbacks const data.

This series starts with a number of cleanups first based on Christoph's
feedback.

This patch (of 9):

No relay client uses the buf_mapped or buf_unmapped callbacks.  Remove
them.  This makes relay's vm_operations_struct close callback a dummy,
remove it as well.

Link: https://lkml.kernel.org/r/cover.1606153547.git.jani.nikula@intel.com
Link: https://lkml.kernel.org/r/c69fff6e0cd485563604240bbfcc028434983bec.1606153547.git.jani.nikula@intel.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Suggested-by: Christoph Hellwig <hch@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
  • Loading branch information
Jani Nikula authored and Linus Torvalds committed Dec 16, 2020
1 parent dc889b8 commit 3d03295
Show file tree
Hide file tree
Showing 2 changed files with 0 additions and 53 deletions.
19 changes: 0 additions & 19 deletions include/linux/relay.h
Original file line number Diff line number Diff line change
Expand Up @@ -101,25 +101,6 @@ struct rchan_callbacks
void *prev_subbuf,
size_t prev_padding);

/*
* buf_mapped - relay buffer mmap notification
* @buf: the channel buffer
* @filp: relay file pointer
*
* Called when a relay file is successfully mmapped
*/
void (*buf_mapped)(struct rchan_buf *buf,
struct file *filp);

/*
* buf_unmapped - relay buffer unmap notification
* @buf: the channel buffer
* @filp: relay file pointer
*
* Called when a relay file is successfully unmapped
*/
void (*buf_unmapped)(struct rchan_buf *buf,
struct file *filp);
/*
* create_buf_file - create file to represent a relay channel buffer
* @filename: the name of the file to create
Expand Down
34 changes: 0 additions & 34 deletions kernel/relay.c
Original file line number Diff line number Diff line change
Expand Up @@ -27,15 +27,6 @@
static DEFINE_MUTEX(relay_channels_mutex);
static LIST_HEAD(relay_channels);

/*
* close() vm_op implementation for relay file mapping.
*/
static void relay_file_mmap_close(struct vm_area_struct *vma)
{
struct rchan_buf *buf = vma->vm_private_data;
buf->chan->cb->buf_unmapped(buf, vma->vm_file);
}

/*
* fault() vm_op implementation for relay file mapping.
*/
Expand All @@ -62,7 +53,6 @@ static vm_fault_t relay_buf_fault(struct vm_fault *vmf)
*/
static const struct vm_operations_struct relay_file_mmap_ops = {
.fault = relay_buf_fault,
.close = relay_file_mmap_close,
};

/*
Expand Down Expand Up @@ -96,7 +86,6 @@ static void relay_free_page_array(struct page **array)
static int relay_mmap_buf(struct rchan_buf *buf, struct vm_area_struct *vma)
{
unsigned long length = vma->vm_end - vma->vm_start;
struct file *filp = vma->vm_file;

if (!buf)
return -EBADF;
Expand All @@ -107,7 +96,6 @@ static int relay_mmap_buf(struct rchan_buf *buf, struct vm_area_struct *vma)
vma->vm_ops = &relay_file_mmap_ops;
vma->vm_flags |= VM_DONTEXPAND;
vma->vm_private_data = buf;
buf->chan->cb->buf_mapped(buf, filp);

return 0;
}
Expand Down Expand Up @@ -283,22 +271,6 @@ static int subbuf_start_default_callback (struct rchan_buf *buf,
return 1;
}

/*
* buf_mapped() default callback. Does nothing.
*/
static void buf_mapped_default_callback(struct rchan_buf *buf,
struct file *filp)
{
}

/*
* buf_unmapped() default callback. Does nothing.
*/
static void buf_unmapped_default_callback(struct rchan_buf *buf,
struct file *filp)
{
}

/*
* create_buf_file_create() default callback. Does nothing.
*/
Expand All @@ -322,8 +294,6 @@ static int remove_buf_file_default_callback(struct dentry *dentry)
/* relay channel default callbacks */
static struct rchan_callbacks default_channel_callbacks = {
.subbuf_start = subbuf_start_default_callback,
.buf_mapped = buf_mapped_default_callback,
.buf_unmapped = buf_unmapped_default_callback,
.create_buf_file = create_buf_file_default_callback,
.remove_buf_file = remove_buf_file_default_callback,
};
Expand Down Expand Up @@ -509,10 +479,6 @@ static void setup_callbacks(struct rchan *chan,

if (!cb->subbuf_start)
cb->subbuf_start = subbuf_start_default_callback;
if (!cb->buf_mapped)
cb->buf_mapped = buf_mapped_default_callback;
if (!cb->buf_unmapped)
cb->buf_unmapped = buf_unmapped_default_callback;
if (!cb->create_buf_file)
cb->create_buf_file = create_buf_file_default_callback;
if (!cb->remove_buf_file)
Expand Down

0 comments on commit 3d03295

Please sign in to comment.