mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/
synced 2026-11-10 20:48:12 +00:00
e661e17ddb
The per-fid readdir buffer (fid->rdir) is populated lazily and only refilled when fully drained (rdir->head == rdir->tail). userspace lseek() on a directory fd updates file->f_pos via generic_file_llseek() but does not touch the cached buffer, so the next getdents() iterates the stale cache and emits entries from the previous position instead of the one the caller asked for. Track the file position the cached data corresponds to in struct p9_rdir, and drop the cache on entry to iterate_shared when it no longer matches ctx->pos. The 9p protocol's Tread/Treaddir already take an arbitrary offset on every request, so a refill at the new position is always legal; no .llseek override or seek restriction is needed. Reported-by: Pierre Barre <pierre@barre.sh> Link: https://lore.kernel.org/v9fs/496d10b9-40fe-4f81-8014-37497c37ff63@app.fastmail.com/ Signed-off-by: Pierre Barre <pierre@barre.sh> Message-ID: <20260512132032.369281-2-pierre@barre.sh> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
266 lines
5.8 KiB
266 lines
5.8 KiB