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authorDavid Woodhouse <dwmw2@infradead.org>2007-07-23 10:20:10 +0100
committerDavid Woodhouse <dwmw2@infradead.org>2007-07-23 10:20:10 +0100
commit39fe5434cb9de5da40510028b17b96bc4eb312b3 (patch)
tree7a02a317b9ad57da51ca99887c119e779ccf3f13 /fs/splice.c
parent0fc72b81d3111d114ab378935b1cf07680ca1289 (diff)
parentf695baf2df9e0413d3521661070103711545207a (diff)
Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6
Diffstat (limited to 'fs/splice.c')
-rw-r--r--fs/splice.c83
1 files changed, 39 insertions, 44 deletions
diff --git a/fs/splice.c b/fs/splice.c
index ed2ce995475c..0a0973218084 100644
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -28,6 +28,7 @@
#include <linux/module.h>
#include <linux/syscalls.h>
#include <linux/uio.h>
+#include <linux/security.h>
/*
* Attempt to steal a page from a pipe buffer. This should perhaps go into
@@ -264,7 +265,7 @@ __generic_file_splice_read(struct file *in, loff_t *ppos,
unsigned int flags)
{
struct address_space *mapping = in->f_mapping;
- unsigned int loff, nr_pages;
+ unsigned int loff, nr_pages, req_pages;
struct page *pages[PIPE_BUFFERS];
struct partial_page partial[PIPE_BUFFERS];
struct page *page;
@@ -280,28 +281,24 @@ __generic_file_splice_read(struct file *in, loff_t *ppos,
index = *ppos >> PAGE_CACHE_SHIFT;
loff = *ppos & ~PAGE_CACHE_MASK;
- nr_pages = (len + loff + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
-
- if (nr_pages > PIPE_BUFFERS)
- nr_pages = PIPE_BUFFERS;
-
- /*
- * Don't try to 2nd guess the read-ahead logic, call into
- * page_cache_readahead() like the page cache reads would do.
- */
- page_cache_readahead(mapping, &in->f_ra, in, index, nr_pages);
+ req_pages = (len + loff + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
+ nr_pages = min(req_pages, (unsigned)PIPE_BUFFERS);
/*
* Lookup the (hopefully) full range of pages we need.
*/
spd.nr_pages = find_get_pages_contig(mapping, index, nr_pages, pages);
+ index += spd.nr_pages;
/*
* If find_get_pages_contig() returned fewer pages than we needed,
- * allocate the rest and fill in the holes.
+ * readahead/allocate the rest and fill in the holes.
*/
+ if (spd.nr_pages < nr_pages)
+ page_cache_sync_readahead(mapping, &in->f_ra, in,
+ index, req_pages - spd.nr_pages);
+
error = 0;
- index += spd.nr_pages;
while (spd.nr_pages < nr_pages) {
/*
* Page could be there, find_get_pages_contig() breaks on
@@ -310,12 +307,6 @@ __generic_file_splice_read(struct file *in, loff_t *ppos,
page = find_get_page(mapping, index);
if (!page) {
/*
- * Make sure the read-ahead engine is notified
- * about this failure.
- */
- handle_ra_miss(mapping, &in->f_ra, index);
-
- /*
* page didn't exist, allocate one.
*/
page = page_cache_alloc_cold(mapping);
@@ -360,6 +351,10 @@ __generic_file_splice_read(struct file *in, loff_t *ppos,
this_len = min_t(unsigned long, len, PAGE_CACHE_SIZE - loff);
page = pages[page_nr];
+ if (PageReadahead(page))
+ page_cache_async_readahead(mapping, &in->f_ra, in,
+ page, index, req_pages - page_nr);
+
/*
* If the page isn't uptodate, we may need to start io on it
*/
@@ -452,6 +447,7 @@ fill_it:
*/
while (page_nr < nr_pages)
page_cache_release(pages[page_nr++]);
+ in->f_ra.prev_index = index;
if (spd.nr_pages)
return splice_to_pipe(pipe, &spd);
@@ -491,7 +487,7 @@ ssize_t generic_file_splice_read(struct file *in, loff_t *ppos,
ret = 0;
spliced = 0;
- while (len) {
+ while (len && !spliced) {
ret = __generic_file_splice_read(in, ppos, pipe, len, flags);
if (ret < 0)
@@ -598,7 +594,7 @@ find_page:
ret = add_to_page_cache_lru(page, mapping, index,
GFP_KERNEL);
if (unlikely(ret))
- goto out;
+ goto out_release;
}
ret = mapping->a_ops->prepare_write(file, page, offset, offset+this_len);
@@ -654,8 +650,9 @@ find_page:
*/
mark_page_accessed(page);
out:
- page_cache_release(page);
unlock_page(page);
+out_release:
+ page_cache_release(page);
out_ret:
return ret;
}
@@ -961,6 +958,10 @@ static long do_splice_from(struct pipe_inode_info *pipe, struct file *out,
if (unlikely(ret < 0))
return ret;
+ ret = security_file_permission(out, MAY_WRITE);
+ if (unlikely(ret < 0))
+ return ret;
+
return out->f_op->splice_write(pipe, out, ppos, len, flags);
}
@@ -983,6 +984,10 @@ static long do_splice_to(struct file *in, loff_t *ppos,
if (unlikely(ret < 0))
return ret;
+ ret = security_file_permission(in, MAY_READ);
+ if (unlikely(ret < 0))
+ return ret;
+
return in->f_op->splice_read(in, ppos, pipe, len, flags);
}
@@ -1051,15 +1056,11 @@ ssize_t splice_direct_to_actor(struct file *in, struct splice_desc *sd,
sd->flags &= ~SPLICE_F_NONBLOCK;
while (len) {
- size_t read_len, max_read_len;
+ size_t read_len;
+ loff_t pos = sd->pos;
- /*
- * Do at most PIPE_BUFFERS pages worth of transfer:
- */
- max_read_len = min(len, (size_t)(PIPE_BUFFERS*PAGE_SIZE));
-
- ret = do_splice_to(in, &sd->pos, pipe, max_read_len, flags);
- if (unlikely(ret < 0))
+ ret = do_splice_to(in, &pos, pipe, len, flags);
+ if (unlikely(ret <= 0))
goto out_release;
read_len = ret;
@@ -1071,26 +1072,18 @@ ssize_t splice_direct_to_actor(struct file *in, struct splice_desc *sd,
* could get stuck data in the internal pipe:
*/
ret = actor(pipe, sd);
- if (unlikely(ret < 0))
+ if (unlikely(ret <= 0))
goto out_release;
bytes += ret;
len -= ret;
+ sd->pos = pos;
- /*
- * In nonblocking mode, if we got back a short read then
- * that was due to either an IO error or due to the
- * pagecache entry not being there. In the IO error case
- * the _next_ splice attempt will produce a clean IO error
- * return value (not a short read), so in both cases it's
- * correct to break out of the loop here:
- */
- if ((flags & SPLICE_F_NONBLOCK) && (read_len < max_read_len))
- break;
+ if (ret < read_len)
+ goto out_release;
}
pipe->nrbufs = pipe->curbuf = 0;
-
return bytes;
out_release:
@@ -1152,10 +1145,12 @@ long do_splice_direct(struct file *in, loff_t *ppos, struct file *out,
.pos = *ppos,
.u.file = out,
};
- size_t ret;
+ long ret;
ret = splice_direct_to_actor(in, &sd, direct_splice_actor);
- *ppos = sd.pos;
+ if (ret > 0)
+ *ppos += ret;
+
return ret;
}