If an NFS file is opened for writing and closed, fscache_invalidate() will be asked to invalidate the file - however, if the cookie is in the LOOKING_UP state (or the CREATING state), then request to invalidate doesn't get recorded for fscache_cookie_state_machine() to do something with. Fix this by making __fscache_invalidate() set a flag if it sees the cookie is in the LOOKING_UP state to indicate that we need to go to invalidation. Note that this requires a count on the n_accesses counter for the state machine, which that will release when it's done. fscache_cookie_state_machine() then shifts to the INVALIDATING state if it sees the flag. Without this, an nfs file can get corrupted if it gets modified locally and then read locally as the cache contents may not get updated.
Unified · Split
| @@ -522,7 +522,14 @@ static void fscache_perform_lookup(struct fscache_cookie *cookie) · 521 unmodified lines | ||
| 522 | 522 | } |
| 523 | 523 | |
| 524 | 524 | fscache_see_cookie(cookie, fscache_cookie_see_active); |
| 525 | − fscache_set_cookie_state(cookie, FSCACHE_COOKIE_STATE_ACTIVE); | |
| 525 | + spin_lock(&cookie->lock); | |
| 526 | + if (test_and_clear_bit(FSCACHE_COOKIE_DO_INVALIDATE, &cookie->flags)) | |
| 527 | + __fscache_set_cookie_state(cookie, | |
| 528 | + FSCACHE_COOKIE_STATE_INVALIDATING); | |
| 529 | + else | |
| 530 | + __fscache_set_cookie_state(cookie, FSCACHE_COOKIE_STATE_ACTIVE); | |
| 531 | + spin_unlock(&cookie->lock); | |
| 532 | + wake_up_cookie_state(cookie); | |
| 526 | 533 | trace = fscache_access_lookup_cookie_end; |
| 527 | 534 | |
| 528 | 535 | out: |
| @@ -757,6 +764,9 @@ again_locked: · 228 unmodified lines | ||
| 757 | 764 | spin_lock(&cookie->lock); |
| 758 | 765 | } |
| 759 | 766 | |
| 767 | + if (test_and_clear_bit(FSCACHE_COOKIE_DO_INVALIDATE, &cookie->flags)) | |
| 768 | + fscache_end_cookie_access(cookie, fscache_access_invalidate_cookie_end); | |
| 769 | + | |
| 760 | 770 | switch (state) { |
| 761 | 771 | case FSCACHE_COOKIE_STATE_RELINQUISHING: |
| 762 | 772 | fscache_see_cookie(cookie, fscache_cookie_see_relinquish); |
| @@ -1053,6 +1063,9 @@ void __fscache_invalidate(struct fscache_cookie *cookie, · 290 unmodified lines | ||
| 1053 | 1063 | return; |
| 1054 | 1064 | |
| 1055 | 1065 | case FSCACHE_COOKIE_STATE_LOOKING_UP: |
| 1066 | + __fscache_begin_cookie_access(cookie, fscache_access_invalidate_cookie); | |
| 1067 | + set_bit(FSCACHE_COOKIE_DO_INVALIDATE, &cookie->flags); | |
| 1068 | + fallthrough; | |
| 1056 | 1069 | case FSCACHE_COOKIE_STATE_CREATING: |
| 1057 | 1070 | spin_unlock(&cookie->lock); |
| 1058 | 1071 | _leave(" [look %x]", cookie->inval_counter); |
| @@ -130,6 +130,7 @@ struct fscache_cookie { · 129 unmodified lines | ||
| 130 | 130 | #define FSCACHE_COOKIE_DO_PREP_TO_WRITE 12 /* T if cookie needs write preparation */ |
| 131 | 131 | #define FSCACHE_COOKIE_HAVE_DATA 13 /* T if this cookie has data stored */ |
| 132 | 132 | #define FSCACHE_COOKIE_IS_HASHED 14 /* T if this cookie is hashed */ |
| 133 | +#define FSCACHE_COOKIE_DO_INVALIDATE 15 /* T if cookie needs invalidation */ | |
| 133 | 134 | |
| 134 | 135 | enum fscache_cookie_state state; |
| 135 | 136 | u8 advice; /* FSCACHE_ADV_* */ |