diff options
| author | Mykyta Yatsenko <yatsenko@meta.com> | 2025-10-26 20:38:47 +0000 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2025-10-27 09:56:27 -0700 |
| commit | 5a5fff604fa30a581197dca4204c35539fbedddb (patch) | |
| tree | 4775d0d03cc26e0a1e62f58f46172cab4d958af0 /lib/buildid.c | |
| parent | 76e4fed847124690f7344a43d01dbcd7b2925353 (diff) | |
lib/freader: support reading more than 2 folios
freader_fetch currently reads from at most two folios. When a read spans
into a third folio, the overflow bytes are copied adjacent to the second
folio’s data instead of being handled as a separate folio.
This patch modifies fetch algorithm to support reading from many folios.
Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Reviewed-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20251026203853.135105-5-mykyta.yatsenko5@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'lib/buildid.c')
| -rw-r--r-- | lib/buildid.c | 27 |
1 files changed, 15 insertions, 12 deletions
diff --git a/lib/buildid.c b/lib/buildid.c index df06e492810d..aaf61dfc0919 100644 --- a/lib/buildid.c +++ b/lib/buildid.c @@ -108,18 +108,21 @@ const void *freader_fetch(struct freader *r, loff_t file_off, size_t sz) */ folio_sz = folio_size(r->folio); if (file_off + sz > r->folio_off + folio_sz) { - int part_sz = r->folio_off + folio_sz - file_off; - - /* copy the part that resides in the current folio */ - memcpy(r->buf, r->addr + (file_off - r->folio_off), part_sz); - - /* fetch next folio */ - r->err = freader_get_folio(r, r->folio_off + folio_sz); - if (r->err) - return NULL; - - /* copy the rest of requested data */ - memcpy(r->buf + part_sz, r->addr, sz - part_sz); + u64 part_sz = r->folio_off + folio_sz - file_off, off; + + memcpy(r->buf, r->addr + file_off - r->folio_off, part_sz); + off = part_sz; + + while (off < sz) { + /* fetch next folio */ + r->err = freader_get_folio(r, r->folio_off + folio_sz); + if (r->err) + return NULL; + folio_sz = folio_size(r->folio); + part_sz = min_t(u64, sz - off, folio_sz); + memcpy(r->buf + off, r->addr, part_sz); + off += part_sz; + } return r->buf; } |