| Message ID | 169507873100.772278.2320683121600245730.stgit@frogsfrogsfrogs (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | iomap: fix unshare data corruption bug | expand |
"Darrick J. Wong" <djwong@kernel.org> writes: > From: Darrick J. Wong <djwong@kernel.org> > > Convert iomap_unshare_iter to create large folios if possible, since the > write and zeroing paths already do that. I think this got missed in the > conversion of the write paths that landed in 6.6-rc1. > > Cc: ritesh.list@gmail.com, willy@infradead.org > Signed-off-by: Darrick J. Wong <djwong@kernel.org> > --- > fs/iomap/buffered-io.c | 22 +++++++++++++--------- > 1 file changed, 13 insertions(+), 9 deletions(-) Looks right to me. Feel free to add - Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com> (small nit below) > > > diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c > index 0350830fc989..db889bdfd327 100644 > --- a/fs/iomap/buffered-io.c > +++ b/fs/iomap/buffered-io.c > @@ -1263,7 +1263,6 @@ static loff_t iomap_unshare_iter(struct iomap_iter *iter) > const struct iomap *srcmap = iomap_iter_srcmap(iter); > loff_t pos = iter->pos; > loff_t length = iomap_length(iter); > - long status = 0; > loff_t written = 0; > > /* don't bother with blocks that are not shared to start with */ > @@ -1274,9 +1273,10 @@ static loff_t iomap_unshare_iter(struct iomap_iter *iter) > return length; > > do { > - unsigned long offset = offset_in_page(pos); > - unsigned long bytes = min_t(loff_t, PAGE_SIZE - offset, length); > struct folio *folio; > + int status; > + size_t offset; > + size_t bytes = min_t(u64, SIZE_MAX, length); > > status = iomap_write_begin(iter, pos, bytes, &folio); > if (unlikely(status)) > @@ -1284,18 +1284,22 @@ static loff_t iomap_unshare_iter(struct iomap_iter *iter) > if (iter->iomap.flags & IOMAP_F_STALE) Just noticed that we already have "iomap = &iter->iomap" at the start of this function. We need not dereference for iomap again here. (Not related to this patch, but I thought I will mention while we are still at it) > break; > > - status = iomap_write_end(iter, pos, bytes, bytes, folio); > - if (WARN_ON_ONCE(status == 0)) > + offset = offset_in_folio(folio, pos); > + if (bytes > folio_size(folio) - offset) > + bytes = folio_size(folio) - offset; > + > + bytes = iomap_write_end(iter, pos, bytes, bytes, folio); > + if (WARN_ON_ONCE(bytes == 0)) > return -EIO; > > cond_resched(); > > - pos += status; > - written += status; > - length -= status; > + pos += bytes; > + written += bytes; > + length -= bytes; > > balance_dirty_pages_ratelimited(iter->inode->i_mapping); > - } while (length); > + } while (length > 0); > > return written; > }
diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c index 0350830fc989..db889bdfd327 100644 --- a/fs/iomap/buffered-io.c +++ b/fs/iomap/buffered-io.c @@ -1263,7 +1263,6 @@ static loff_t iomap_unshare_iter(struct iomap_iter *iter) const struct iomap *srcmap = iomap_iter_srcmap(iter); loff_t pos = iter->pos; loff_t length = iomap_length(iter); - long status = 0; loff_t written = 0; /* don't bother with blocks that are not shared to start with */ @@ -1274,9 +1273,10 @@ static loff_t iomap_unshare_iter(struct iomap_iter *iter) return length; do { - unsigned long offset = offset_in_page(pos); - unsigned long bytes = min_t(loff_t, PAGE_SIZE - offset, length); struct folio *folio; + int status; + size_t offset; + size_t bytes = min_t(u64, SIZE_MAX, length); status = iomap_write_begin(iter, pos, bytes, &folio); if (unlikely(status)) @@ -1284,18 +1284,22 @@ static loff_t iomap_unshare_iter(struct iomap_iter *iter) if (iter->iomap.flags & IOMAP_F_STALE) break; - status = iomap_write_end(iter, pos, bytes, bytes, folio); - if (WARN_ON_ONCE(status == 0)) + offset = offset_in_folio(folio, pos); + if (bytes > folio_size(folio) - offset) + bytes = folio_size(folio) - offset; + + bytes = iomap_write_end(iter, pos, bytes, bytes, folio); + if (WARN_ON_ONCE(bytes == 0)) return -EIO; cond_resched(); - pos += status; - written += status; - length -= status; + pos += bytes; + written += bytes; + length -= bytes; balance_dirty_pages_ratelimited(iter->inode->i_mapping); - } while (length); + } while (length > 0); return written; }