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| author | Al Viro <viro@zeniv.linux.org.uk> | 2021-04-27 12:34:04 -0400 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2021-06-03 10:36:51 -0400 |
| commit | a506abc7b644d71966a75337d5a534f531b3cdc4 (patch) | |
| tree | f5a2e285bc2be4d018eb988d90228a414974f997 /lib/iov_iter.c | |
| parent | 08aa64796016cb47b2ef3d0924653b4d944b0d65 (diff) | |
| download | lwn-a506abc7b644d71966a75337d5a534f531b3cdc4.tar.gz lwn-a506abc7b644d71966a75337d5a534f531b3cdc4.zip | |
copy_page_to_iter(): fix ITER_DISCARD case
we need to advance the iterator...
Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'lib/iov_iter.c')
| -rw-r--r-- | lib/iov_iter.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/lib/iov_iter.c b/lib/iov_iter.c index 12fb04b23143..c8877cffb7bc 100644 --- a/lib/iov_iter.c +++ b/lib/iov_iter.c @@ -965,9 +965,12 @@ static size_t __copy_page_to_iter(struct page *page, size_t offset, size_t bytes size_t wanted = copy_to_iter(kaddr + offset, bytes, i); kunmap_atomic(kaddr); return wanted; - } else if (unlikely(iov_iter_is_discard(i))) + } else if (unlikely(iov_iter_is_discard(i))) { + if (unlikely(i->count < bytes)) + bytes = i->count; + i->count -= bytes; return bytes; - else if (likely(!iov_iter_is_pipe(i))) + } else if (likely(!iov_iter_is_pipe(i))) return copy_page_to_iter_iovec(page, offset, bytes, i); else return copy_page_to_iter_pipe(page, offset, bytes, i); |