There were a few places that were incorrectly testing for whether an
open(2) operation was O_TMPFILE by doing (flags & O_TMPFILE). As
O_TMPFILE is defined as __O_TMPFILE|O_DIRECTORY, this would cause the
code to assume that O_DIRECTORY is equivalent to O_TMPFILE.
The only places where this happened were in RESOLVE_CACHED and
io_uring's checking related to RESOLVE_CACHED, so the only bug this
really fixes is that now O_DIRECTORY will no longer cause RESOLVE_CACHED
to always fail with -EAGAIN (and io_uring will thus be faster when doing
O_DIRECTORY opens).
Signed-off-by: Aleksa Sarai <[email protected]>
---
Changes in v2:
- fix io_uring's io_openat_force_async as well.
- v1: <https://lore.kernel.org/r/[email protected]>
---
Aleksa Sarai (2):
open: make RESOLVE_CACHED correctly test for O_TMPFILE
io_uring: correct check for O_TMPFILE
fs/open.c | 2 +-
io_uring/openclose.c | 4 ++--
2 files changed, 3 insertions(+), 3 deletions(-)
---
base-commit: bf5ad7af0516cb47121dae1b1c160e4385615274
change-id: 20230806-resolve_cached-o_tmpfile-978cb238bd68
Best regards,
--
Aleksa Sarai <[email protected]>
O_TMPFILE is actually __O_TMPFILE|O_DIRECTORY. This means that the old
fast-path check for RESOLVE_CACHED would reject all users passing
O_DIRECTORY with -EAGAIN, when in fact the intended test was to check
for __O_TMPFILE.
Cc: [email protected] # v5.12+
Fixes: 99668f618062 ("fs: expose LOOKUP_CACHED through openat2() RESOLVE_CACHED")
Signed-off-by: Aleksa Sarai <[email protected]>
---
fs/open.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/open.c b/fs/open.c
index b8883ec286f5..2634047c9e9f 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -1337,7 +1337,7 @@ inline int build_open_flags(const struct open_how *how, struct open_flags *op)
lookup_flags |= LOOKUP_IN_ROOT;
if (how->resolve & RESOLVE_CACHED) {
/* Don't bother even trying for create/truncate/tmpfile open */
- if (flags & (O_TRUNC | O_CREAT | O_TMPFILE))
+ if (flags & (O_TRUNC | O_CREAT | __O_TMPFILE))
return -EAGAIN;
lookup_flags |= LOOKUP_CACHED;
}
--
2.41.0