mirror of
https://github.com/torvalds/linux.git
synced 2024-11-28 23:21:31 +00:00
Merge branch 'splice' of git://brick.kernel.dk/data/git/linux-2.6-block
* 'splice' of git://brick.kernel.dk/data/git/linux-2.6-block: [PATCH] splice: fixup writeout path after ->map changes [PATCH] splice: offset fixes [PATCH] tee: link_pipe() must be careful when dropping one of the pipe locks [PATCH] splice: cleanup the SPLICE_F_NONBLOCK handling [PATCH] splice: close i_size truncate races on read
This commit is contained in:
Linus Torvalds
commit
0efd9323f3
163
fs/splice.c
163
fs/splice.c
@ -50,7 +50,8 @@ static int page_cache_pipe_buf_steal(struct pipe_inode_info *info,
|
||||
struct page *page = buf->page;
|
||||
struct address_space *mapping = page_mapping(page);
|
||||
|
||||
WARN_ON(!PageLocked(page));
|
||||
lock_page(page);
|
||||
|
||||
WARN_ON(!PageUptodate(page));
|
||||
|
||||
/*
|
||||
@ -65,8 +66,10 @@ static int page_cache_pipe_buf_steal(struct pipe_inode_info *info,
|
||||
if (PagePrivate(page))
|
||||
try_to_release_page(page, mapping_gfp_mask(mapping));
|
||||
|
||||
if (!remove_mapping(mapping, page))
|
||||
if (!remove_mapping(mapping, page)) {
|
||||
unlock_page(page);
|
||||
return 1;
|
||||
}
|
||||
|
||||
buf->flags |= PIPE_BUF_FLAG_STOLEN | PIPE_BUF_FLAG_LRU;
|
||||
return 0;
|
||||
@ -145,8 +148,8 @@ static struct pipe_buf_operations page_cache_pipe_buf_ops = {
|
||||
* pipe buffer operations. Otherwise very similar to the regular pipe_writev().
|
||||
*/
|
||||
static ssize_t move_to_pipe(struct pipe_inode_info *pipe, struct page **pages,
|
||||
int nr_pages, unsigned long offset,
|
||||
unsigned long len, unsigned int flags)
|
||||
int nr_pages, unsigned long len,
|
||||
unsigned int offset, unsigned int flags)
|
||||
{
|
||||
int ret, do_wakeup, i;
|
||||
|
||||
@ -243,14 +246,16 @@ __generic_file_splice_read(struct file *in, loff_t *ppos,
|
||||
unsigned int flags)
|
||||
{
|
||||
struct address_space *mapping = in->f_mapping;
|
||||
unsigned int offset, nr_pages;
|
||||
unsigned int loff, offset, nr_pages;
|
||||
struct page *pages[PIPE_BUFFERS];
|
||||
struct page *page;
|
||||
pgoff_t index;
|
||||
pgoff_t index, end_index;
|
||||
loff_t isize;
|
||||
size_t bytes;
|
||||
int i, error;
|
||||
|
||||
index = *ppos >> PAGE_CACHE_SHIFT;
|
||||
offset = *ppos & ~PAGE_CACHE_MASK;
|
||||
loff = offset = *ppos & ~PAGE_CACHE_MASK;
|
||||
nr_pages = (len + offset + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
|
||||
|
||||
if (nr_pages > PIPE_BUFFERS)
|
||||
@ -268,6 +273,7 @@ __generic_file_splice_read(struct file *in, loff_t *ppos,
|
||||
* Now fill in the holes:
|
||||
*/
|
||||
error = 0;
|
||||
bytes = 0;
|
||||
for (i = 0; i < nr_pages; i++, index++) {
|
||||
find_page:
|
||||
/*
|
||||
@ -275,14 +281,6 @@ find_page:
|
||||
*/
|
||||
page = find_get_page(mapping, index);
|
||||
if (!page) {
|
||||
/*
|
||||
* If in nonblock mode then dont block on
|
||||
* readpage (we've kicked readahead so there
|
||||
* will be asynchronous progress):
|
||||
*/
|
||||
if (flags & SPLICE_F_NONBLOCK)
|
||||
break;
|
||||
|
||||
/*
|
||||
* page didn't exist, allocate one
|
||||
*/
|
||||
@ -304,6 +302,13 @@ find_page:
|
||||
* If the page isn't uptodate, we may need to start io on it
|
||||
*/
|
||||
if (!PageUptodate(page)) {
|
||||
/*
|
||||
* If in nonblock mode then dont block on waiting
|
||||
* for an in-flight io page
|
||||
*/
|
||||
if (flags & SPLICE_F_NONBLOCK)
|
||||
break;
|
||||
|
||||
lock_page(page);
|
||||
|
||||
/*
|
||||
@ -336,13 +341,41 @@ readpage:
|
||||
goto find_page;
|
||||
break;
|
||||
}
|
||||
|
||||
/*
|
||||
* i_size must be checked after ->readpage().
|
||||
*/
|
||||
isize = i_size_read(mapping->host);
|
||||
end_index = (isize - 1) >> PAGE_CACHE_SHIFT;
|
||||
if (unlikely(!isize || index > end_index)) {
|
||||
page_cache_release(page);
|
||||
break;
|
||||
}
|
||||
|
||||
/*
|
||||
* if this is the last page, see if we need to shrink
|
||||
* the length and stop
|
||||
*/
|
||||
if (end_index == index) {
|
||||
loff = PAGE_CACHE_SIZE - (isize & ~PAGE_CACHE_MASK);
|
||||
if (bytes + loff > isize) {
|
||||
page_cache_release(page);
|
||||
break;
|
||||
}
|
||||
/*
|
||||
* force quit after adding this page
|
||||
*/
|
||||
nr_pages = i;
|
||||
}
|
||||
}
|
||||
fill_it:
|
||||
pages[i] = page;
|
||||
bytes += PAGE_CACHE_SIZE - loff;
|
||||
loff = 0;
|
||||
}
|
||||
|
||||
if (i)
|
||||
return move_to_pipe(pipe, pages, i, offset, len, flags);
|
||||
return move_to_pipe(pipe, pages, i, bytes, offset, flags);
|
||||
|
||||
return error;
|
||||
}
|
||||
@ -369,17 +402,20 @@ ssize_t generic_file_splice_read(struct file *in, loff_t *ppos,
|
||||
while (len) {
|
||||
ret = __generic_file_splice_read(in, ppos, pipe, len, flags);
|
||||
|
||||
if (ret <= 0)
|
||||
if (ret < 0)
|
||||
break;
|
||||
else if (!ret) {
|
||||
if (spliced)
|
||||
break;
|
||||
if (flags & SPLICE_F_NONBLOCK) {
|
||||
ret = -EAGAIN;
|
||||
break;
|
||||
}
|
||||
}
|
||||
|
||||
*ppos += ret;
|
||||
len -= ret;
|
||||
spliced += ret;
|
||||
|
||||
if (!(flags & SPLICE_F_NONBLOCK))
|
||||
continue;
|
||||
ret = -EAGAIN;
|
||||
break;
|
||||
}
|
||||
|
||||
if (spliced)
|
||||
@ -474,14 +510,12 @@ static int pipe_to_file(struct pipe_inode_info *info, struct pipe_buffer *buf,
|
||||
if (sd->flags & SPLICE_F_MOVE) {
|
||||
/*
|
||||
* If steal succeeds, buf->page is now pruned from the vm
|
||||
* side (LRU and page cache) and we can reuse it.
|
||||
* side (LRU and page cache) and we can reuse it. The page
|
||||
* will also be looked on successful return.
|
||||
*/
|
||||
if (buf->ops->steal(info, buf))
|
||||
goto find_page;
|
||||
|
||||
/*
|
||||
* this will also set the page locked
|
||||
*/
|
||||
page = buf->page;
|
||||
if (add_to_page_cache(page, mapping, index, gfp_mask))
|
||||
goto find_page;
|
||||
@ -490,15 +524,27 @@ static int pipe_to_file(struct pipe_inode_info *info, struct pipe_buffer *buf,
|
||||
lru_cache_add(page);
|
||||
} else {
|
||||
find_page:
|
||||
page = find_lock_page(mapping, index);
|
||||
if (!page) {
|
||||
ret = -ENOMEM;
|
||||
page = find_or_create_page(mapping, index, gfp_mask);
|
||||
if (!page)
|
||||
page = page_cache_alloc_cold(mapping);
|
||||
if (unlikely(!page))
|
||||
goto out_nomem;
|
||||
|
||||
/*
|
||||
* If the page is uptodate, it is also locked. If it isn't
|
||||
* uptodate, we can mark it uptodate if we are filling the
|
||||
* full page. Otherwise we need to read it in first...
|
||||
* This will also lock the page
|
||||
*/
|
||||
ret = add_to_page_cache_lru(page, mapping, index,
|
||||
gfp_mask);
|
||||
if (unlikely(ret))
|
||||
goto out;
|
||||
}
|
||||
|
||||
/*
|
||||
* We get here with the page locked. If the page is also
|
||||
* uptodate, we don't need to do more. If it isn't, we
|
||||
* may need to bring it in if we are not going to overwrite
|
||||
* the full page.
|
||||
*/
|
||||
if (!PageUptodate(page)) {
|
||||
if (sd->len < PAGE_CACHE_SIZE) {
|
||||
@ -520,12 +566,10 @@ find_page:
|
||||
ret = -EIO;
|
||||
goto out;
|
||||
}
|
||||
} else {
|
||||
WARN_ON(!PageLocked(page));
|
||||
} else
|
||||
SetPageUptodate(page);
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
ret = mapping->a_ops->prepare_write(file, page, 0, sd->len);
|
||||
if (ret == AOP_TRUNCATED_PAGE) {
|
||||
@ -552,10 +596,10 @@ find_page:
|
||||
mark_page_accessed(page);
|
||||
balance_dirty_pages_ratelimited(mapping);
|
||||
out:
|
||||
if (!(buf->flags & PIPE_BUF_FLAG_STOLEN)) {
|
||||
if (!(buf->flags & PIPE_BUF_FLAG_STOLEN))
|
||||
page_cache_release(page);
|
||||
|
||||
unlock_page(page);
|
||||
}
|
||||
out_nomem:
|
||||
buf->ops->unmap(info, buf);
|
||||
return ret;
|
||||
@ -687,23 +731,27 @@ generic_file_splice_write(struct pipe_inode_info *pipe, struct file *out,
|
||||
ssize_t ret;
|
||||
|
||||
ret = move_from_pipe(pipe, out, ppos, len, flags, pipe_to_file);
|
||||
if (ret > 0) {
|
||||
struct inode *inode = mapping->host;
|
||||
|
||||
*ppos += ret;
|
||||
|
||||
/*
|
||||
* If file or inode is SYNC and we actually wrote some data, sync it.
|
||||
* If file or inode is SYNC and we actually wrote some data,
|
||||
* sync it.
|
||||
*/
|
||||
if (unlikely((out->f_flags & O_SYNC) || IS_SYNC(mapping->host))
|
||||
&& ret > 0) {
|
||||
struct inode *inode = mapping->host;
|
||||
if (unlikely((out->f_flags & O_SYNC) || IS_SYNC(inode))) {
|
||||
int err;
|
||||
|
||||
mutex_lock(&inode->i_mutex);
|
||||
err = generic_osync_inode(mapping->host, mapping,
|
||||
err = generic_osync_inode(inode, mapping,
|
||||
OSYNC_METADATA|OSYNC_DATA);
|
||||
mutex_unlock(&inode->i_mutex);
|
||||
|
||||
if (err)
|
||||
ret = err;
|
||||
}
|
||||
}
|
||||
|
||||
return ret;
|
||||
}
|
||||
@ -904,6 +952,7 @@ static long do_splice(struct file *in, loff_t __user *off_in,
|
||||
{
|
||||
struct pipe_inode_info *pipe;
|
||||
loff_t offset, *off;
|
||||
long ret;
|
||||
|
||||
pipe = in->f_dentry->d_inode->i_pipe;
|
||||
if (pipe) {
|
||||
@ -918,7 +967,12 @@ static long do_splice(struct file *in, loff_t __user *off_in,
|
||||
} else
|
||||
off = &out->f_pos;
|
||||
|
||||
return do_splice_from(pipe, out, off, len, flags);
|
||||
ret = do_splice_from(pipe, out, off, len, flags);
|
||||
|
||||
if (off_out && copy_to_user(off_out, off, sizeof(loff_t)))
|
||||
ret = -EFAULT;
|
||||
|
||||
return ret;
|
||||
}
|
||||
|
||||
pipe = out->f_dentry->d_inode->i_pipe;
|
||||
@ -934,7 +988,12 @@ static long do_splice(struct file *in, loff_t __user *off_in,
|
||||
} else
|
||||
off = &in->f_pos;
|
||||
|
||||
return do_splice_to(in, off, pipe, len, flags);
|
||||
ret = do_splice_to(in, off, pipe, len, flags);
|
||||
|
||||
if (off_in && copy_to_user(off_in, off, sizeof(loff_t)))
|
||||
ret = -EFAULT;
|
||||
|
||||
return ret;
|
||||
}
|
||||
|
||||
return -EINVAL;
|
||||
@ -979,7 +1038,9 @@ static int link_pipe(struct pipe_inode_info *ipipe,
|
||||
size_t len, unsigned int flags)
|
||||
{
|
||||
struct pipe_buffer *ibuf, *obuf;
|
||||
int ret = 0, do_wakeup = 0, i;
|
||||
int ret, do_wakeup, i, ipipe_first;
|
||||
|
||||
ret = do_wakeup = ipipe_first = 0;
|
||||
|
||||
/*
|
||||
* Potential ABBA deadlock, work around it by ordering lock
|
||||
@ -987,6 +1048,7 @@ static int link_pipe(struct pipe_inode_info *ipipe,
|
||||
* could deadlock (one doing tee from A -> B, the other from B -> A).
|
||||
*/
|
||||
if (ipipe->inode < opipe->inode) {
|
||||
ipipe_first = 1;
|
||||
mutex_lock(&ipipe->inode->i_mutex);
|
||||
mutex_lock(&opipe->inode->i_mutex);
|
||||
} else {
|
||||
@ -1035,9 +1097,11 @@ static int link_pipe(struct pipe_inode_info *ipipe,
|
||||
|
||||
/*
|
||||
* We have input available, but no output room.
|
||||
* If we already copied data, return that.
|
||||
* If we already copied data, return that. If we
|
||||
* need to drop the opipe lock, it must be ordered
|
||||
* last to avoid deadlocks.
|
||||
*/
|
||||
if (flags & SPLICE_F_NONBLOCK) {
|
||||
if ((flags & SPLICE_F_NONBLOCK) || !ipipe_first) {
|
||||
if (!ret)
|
||||
ret = -EAGAIN;
|
||||
break;
|
||||
@ -1071,7 +1135,12 @@ static int link_pipe(struct pipe_inode_info *ipipe,
|
||||
if (ret)
|
||||
break;
|
||||
}
|
||||
if (flags & SPLICE_F_NONBLOCK) {
|
||||
/*
|
||||
* pipe_wait() drops the ipipe mutex. To avoid deadlocks
|
||||
* with another process, we can only safely do that if
|
||||
* the ipipe lock is ordered last.
|
||||
*/
|
||||
if ((flags & SPLICE_F_NONBLOCK) || ipipe_first) {
|
||||
if (!ret)
|
||||
ret = -EAGAIN;
|
||||
break;
|
||||
|
||||
Loading…
Reference in New Issue
Block a user