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authorLinus Torvalds <torvalds@linux-foundation.org>2012-07-03 15:45:10 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2012-07-03 15:45:10 -0700
commita3da2c6913469ecb2224d891c45470b37b4d67f4 (patch)
treecbedea8d0c8c101cfffccdbaf273e7adf92a4e46 /fs
parentff826b2b5b269ad440afa686ede879ccabfda387 (diff)
parent6d9359280753d2955f86d6411047516a9431eb51 (diff)
downloadlwn-a3da2c6913469ecb2224d891c45470b37b4d67f4.tar.gz
lwn-a3da2c6913469ecb2224d891c45470b37b4d67f4.zip
Merge branch 'for-linus' of git://git.kernel.dk/linux-block
Pull block bits from Jens Axboe: "As vacation is coming up, thought I'd better get rid of my pending changes in my for-linus branch for this iteration. It contains: - Two patches for mtip32xx. Killing a non-compliant sysfs interface and moving it to debugfs, where it belongs. - A few patches from Asias. Two legit bug fixes, and one killing an interface that is no longer in use. - A patch from Jan, making the annoying partition ioctl warning a bit less annoying, by restricting it to !CAP_SYS_RAWIO only. - Three bug fixes for drbd from Lars Ellenberg. - A fix for an old regression for umem, it hasn't really worked since the plugging scheme was changed in 3.0. - A few fixes from Tejun. - A splice fix from Eric Dumazet, fixing an issue with pipe resizing." * 'for-linus' of git://git.kernel.dk/linux-block: scsi: Silence unnecessary warnings about ioctl to partition block: Drop dead function blk_abort_queue() block: Mitigate lock unbalance caused by lock switching block: Avoid missed wakeup in request waitqueue umem: fix up unplugging splice: fix racy pipe->buffers uses drbd: fix null pointer dereference with on-congestion policy when diskless drbd: fix list corruption by failing but already aborted reads drbd: fix access of unallocated pages and kernel panic xen/blkfront: Add WARN to deal with misbehaving backends. blkcg: drop local variable @q from blkg_destroy() mtip32xx: Create debugfs entries for troubleshooting mtip32xx: Remove 'registers' and 'flags' from sysfs blkcg: fix blkg_alloc() failure path block: blkcg_policy_cfq shouldn't be used if !CONFIG_CFQ_GROUP_IOSCHED block: fix return value on cfq_init() failure mtip32xx: Remove version.h header file inclusion xen/blkback: Copy id field when doing BLKIF_DISCARD.
Diffstat (limited to 'fs')
-rw-r--r--fs/splice.c35
1 files changed, 20 insertions, 15 deletions
diff --git a/fs/splice.c b/fs/splice.c
index c9f1318a3b82..7bf08fa22ec9 100644
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -273,13 +273,16 @@ void spd_release_page(struct splice_pipe_desc *spd, unsigned int i)
* Check if we need to grow the arrays holding pages and partial page
* descriptions.
*/
-int splice_grow_spd(struct pipe_inode_info *pipe, struct splice_pipe_desc *spd)
+int splice_grow_spd(const struct pipe_inode_info *pipe, struct splice_pipe_desc *spd)
{
- if (pipe->buffers <= PIPE_DEF_BUFFERS)
+ unsigned int buffers = ACCESS_ONCE(pipe->buffers);
+
+ spd->nr_pages_max = buffers;
+ if (buffers <= PIPE_DEF_BUFFERS)
return 0;
- spd->pages = kmalloc(pipe->buffers * sizeof(struct page *), GFP_KERNEL);
- spd->partial = kmalloc(pipe->buffers * sizeof(struct partial_page), GFP_KERNEL);
+ spd->pages = kmalloc(buffers * sizeof(struct page *), GFP_KERNEL);
+ spd->partial = kmalloc(buffers * sizeof(struct partial_page), GFP_KERNEL);
if (spd->pages && spd->partial)
return 0;
@@ -289,10 +292,9 @@ int splice_grow_spd(struct pipe_inode_info *pipe, struct splice_pipe_desc *spd)
return -ENOMEM;
}
-void splice_shrink_spd(struct pipe_inode_info *pipe,
- struct splice_pipe_desc *spd)
+void splice_shrink_spd(struct splice_pipe_desc *spd)
{
- if (pipe->buffers <= PIPE_DEF_BUFFERS)
+ if (spd->nr_pages_max <= PIPE_DEF_BUFFERS)
return;
kfree(spd->pages);
@@ -315,6 +317,7 @@ __generic_file_splice_read(struct file *in, loff_t *ppos,
struct splice_pipe_desc spd = {
.pages = pages,
.partial = partial,
+ .nr_pages_max = PIPE_DEF_BUFFERS,
.flags = flags,
.ops = &page_cache_pipe_buf_ops,
.spd_release = spd_release_page,
@@ -326,7 +329,7 @@ __generic_file_splice_read(struct file *in, loff_t *ppos,
index = *ppos >> PAGE_CACHE_SHIFT;
loff = *ppos & ~PAGE_CACHE_MASK;
req_pages = (len + loff + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
- nr_pages = min(req_pages, pipe->buffers);
+ nr_pages = min(req_pages, spd.nr_pages_max);
/*
* Lookup the (hopefully) full range of pages we need.
@@ -497,7 +500,7 @@ fill_it:
if (spd.nr_pages)
error = splice_to_pipe(pipe, &spd);
- splice_shrink_spd(pipe, &spd);
+ splice_shrink_spd(&spd);
return error;
}
@@ -598,6 +601,7 @@ ssize_t default_file_splice_read(struct file *in, loff_t *ppos,
struct splice_pipe_desc spd = {
.pages = pages,
.partial = partial,
+ .nr_pages_max = PIPE_DEF_BUFFERS,
.flags = flags,
.ops = &default_pipe_buf_ops,
.spd_release = spd_release_page,
@@ -608,8 +612,8 @@ ssize_t default_file_splice_read(struct file *in, loff_t *ppos,
res = -ENOMEM;
vec = __vec;
- if (pipe->buffers > PIPE_DEF_BUFFERS) {
- vec = kmalloc(pipe->buffers * sizeof(struct iovec), GFP_KERNEL);
+ if (spd.nr_pages_max > PIPE_DEF_BUFFERS) {
+ vec = kmalloc(spd.nr_pages_max * sizeof(struct iovec), GFP_KERNEL);
if (!vec)
goto shrink_ret;
}
@@ -617,7 +621,7 @@ ssize_t default_file_splice_read(struct file *in, loff_t *ppos,
offset = *ppos & ~PAGE_CACHE_MASK;
nr_pages = (len + offset + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
- for (i = 0; i < nr_pages && i < pipe->buffers && len; i++) {
+ for (i = 0; i < nr_pages && i < spd.nr_pages_max && len; i++) {
struct page *page;
page = alloc_page(GFP_USER);
@@ -665,7 +669,7 @@ ssize_t default_file_splice_read(struct file *in, loff_t *ppos,
shrink_ret:
if (vec != __vec)
kfree(vec);
- splice_shrink_spd(pipe, &spd);
+ splice_shrink_spd(&spd);
return res;
err:
@@ -1614,6 +1618,7 @@ static long vmsplice_to_pipe(struct file *file, const struct iovec __user *iov,
struct splice_pipe_desc spd = {
.pages = pages,
.partial = partial,
+ .nr_pages_max = PIPE_DEF_BUFFERS,
.flags = flags,
.ops = &user_page_pipe_buf_ops,
.spd_release = spd_release_page,
@@ -1629,13 +1634,13 @@ static long vmsplice_to_pipe(struct file *file, const struct iovec __user *iov,
spd.nr_pages = get_iovec_page_array(iov, nr_segs, spd.pages,
spd.partial, false,
- pipe->buffers);
+ spd.nr_pages_max);
if (spd.nr_pages <= 0)
ret = spd.nr_pages;
else
ret = splice_to_pipe(pipe, &spd);
- splice_shrink_spd(pipe, &spd);
+ splice_shrink_spd(&spd);
return ret;
}