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| author | Jens Axboe <jens.axboe@oracle.com> | 2009-05-13 08:35:35 +0200 |
|---|---|---|
| committer | Jens Axboe <jens.axboe@oracle.com> | 2009-05-13 08:35:35 +0200 |
| commit | 4f23122858a27ba97444b9b37a066d83edebd4c8 (patch) | |
| tree | 7ccfea2b6d606318c9812f0dc9c3aa39411ac456 /fs/splice.c | |
| parent | 2b1ccc0ee918a653d0483fdad9dd6112ce8e9043 (diff) | |
| download | lwn-4f23122858a27ba97444b9b37a066d83edebd4c8.tar.gz lwn-4f23122858a27ba97444b9b37a066d83edebd4c8.zip | |
splice: fix repeated kmap()'s in default_file_splice_read()
We cannot reliably map more than one page at the time, or we risk
deadlocking. Just allocate the pages from low mem instead.
Reported-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Diffstat (limited to 'fs/splice.c')
| -rw-r--r-- | fs/splice.c | 10 |
1 files changed, 4 insertions, 6 deletions
diff --git a/fs/splice.c b/fs/splice.c index eefd96b1d7fb..c5e3c79b95a8 100644 --- a/fs/splice.c +++ b/fs/splice.c @@ -580,13 +580,13 @@ ssize_t default_file_splice_read(struct file *in, loff_t *ppos, for (i = 0; i < nr_pages && i < PIPE_BUFFERS && len; i++) { struct page *page; - page = alloc_page(GFP_HIGHUSER); + page = alloc_page(GFP_USER); error = -ENOMEM; if (!page) goto err; this_len = min_t(size_t, len, PAGE_CACHE_SIZE - offset); - vec[i].iov_base = (void __user *) kmap(page); + vec[i].iov_base = (void __user *) page_address(page); vec[i].iov_len = this_len; pages[i] = page; spd.nr_pages++; @@ -604,7 +604,6 @@ ssize_t default_file_splice_read(struct file *in, loff_t *ppos, nr_freed = 0; for (i = 0; i < spd.nr_pages; i++) { - kunmap(pages[i]); this_len = min_t(size_t, vec[i].iov_len, res); partial[i].offset = 0; partial[i].len = this_len; @@ -624,10 +623,9 @@ ssize_t default_file_splice_read(struct file *in, loff_t *ppos, return res; err: - for (i = 0; i < spd.nr_pages; i++) { - kunmap(pages[i]); + for (i = 0; i < spd.nr_pages; i++) __free_page(pages[i]); - } + return error; } EXPORT_SYMBOL(default_file_splice_read); |