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| author | David Howells <dhowells@redhat.com> | 2021-04-25 22:02:38 +0100 |
|---|---|---|
| committer | David Howells <dhowells@redhat.com> | 2021-04-26 22:55:12 +0100 |
| commit | 3d14ec1fe61aebe3da85a9b8f2c3d61e43d522e6 (patch) | |
| tree | bb6b15242a45a6e6fc08d4e12fd469b0ee3f4565 /lib/iov_iter.c | |
| parent | 26aaeffcafe6cbb7c3978fa6ed7555122f8c9f8c (diff) | |
| download | lwn-3d14ec1fe61aebe3da85a9b8f2c3d61e43d522e6.tar.gz lwn-3d14ec1fe61aebe3da85a9b8f2c3d61e43d522e6.zip | |
iov_iter: Four fixes for ITER_XARRAY
Fix four things[1] in the patch that adds ITER_XARRAY[2]:
(1) Remove the address_space struct predeclaration. This is a holdover
from when it was ITER_MAPPING.
(2) Fix _copy_mc_to_iter() so that the xarray segment updates count and
iov_offset in the iterator before returning.
(3) Fix iov_iter_alignment() to not loop in the xarray case. Because the
middle pages are all whole pages, only the end pages need be
considered - and this can be reduced to just looking at the start
position in the xarray and the iteration size.
(4) Fix iov_iter_advance() to limit the size of the advance to no more
than the remaining iteration size.
Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Al Viro <viro@zeniv.linux.org.uk>
Tested-by: Jeff Layton <jlayton@redhat.com>
Tested-by: Dave Wysochanski <dwysocha@redhat.com>
Link: https://lore.kernel.org/r/YIVrJT8GwLI0Wlgx@zeniv-ca.linux.org.uk [1]
Link: https://lore.kernel.org/r/161918448151.3145707.11541538916600921083.stgit@warthog.procyon.org.uk [2]
Diffstat (limited to 'lib/iov_iter.c')
| -rw-r--r-- | lib/iov_iter.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/lib/iov_iter.c b/lib/iov_iter.c index 44fa726a8323..61228a6c69f8 100644 --- a/lib/iov_iter.c +++ b/lib/iov_iter.c @@ -791,6 +791,8 @@ size_t _copy_mc_to_iter(const void *addr, size_t bytes, struct iov_iter *i) curr_addr = (unsigned long) from; bytes = curr_addr - s_addr - rem; rcu_read_unlock(); + i->iov_offset += bytes; + i->count -= bytes; return bytes; } }) @@ -1147,6 +1149,7 @@ void iov_iter_advance(struct iov_iter *i, size_t size) return; } if (unlikely(iov_iter_is_xarray(i))) { + size = min(size, i->count); i->iov_offset += size; i->count -= size; return; @@ -1346,6 +1349,8 @@ unsigned long iov_iter_alignment(const struct iov_iter *i) return size | i->iov_offset; return size; } + if (unlikely(iov_iter_is_xarray(i))) + return (i->xarray_start + i->iov_offset) | i->count; iterate_all_kinds(i, size, v, (res |= (unsigned long)v.iov_base | v.iov_len, 0), res |= v.bv_offset | v.bv_len, |