diff options
Diffstat (limited to 'drivers/staging')
| -rw-r--r-- | drivers/staging/erofs/unzip_vle.c | 70 |
1 files changed, 45 insertions, 25 deletions
diff --git a/drivers/staging/erofs/unzip_vle.c b/drivers/staging/erofs/unzip_vle.c index 74c13b0a3d33..02f34a83147d 100644 --- a/drivers/staging/erofs/unzip_vle.c +++ b/drivers/staging/erofs/unzip_vle.c @@ -107,15 +107,30 @@ enum z_erofs_vle_work_role { Z_EROFS_VLE_WORK_SECONDARY, Z_EROFS_VLE_WORK_PRIMARY, /* - * The current work has at least been linked with the following - * processed chained works, which means if the processing page - * is the tail partial page of the work, the current work can - * safely use the whole page, as illustrated below: - * +--------------+-------------------------------------------+ - * | tail page | head page (of the previous work) | - * +--------------+-------------------------------------------+ - * /\ which belongs to the current work - * [ (*) this page can be used for the current work itself. ] + * The current work was the tail of an exist chain, and the previous + * processed chained works are all decided to be hooked up to it. + * A new chain should be created for the remaining unprocessed works, + * therefore different from Z_EROFS_VLE_WORK_PRIMARY_FOLLOWED, + * the next work cannot reuse the whole page in the following scenario: + * ________________________________________________________________ + * | tail (partial) page | head (partial) page | + * | (belongs to the next work) | (belongs to the current work) | + * |_______PRIMARY_FOLLOWED_______|________PRIMARY_HOOKED___________| + */ + Z_EROFS_VLE_WORK_PRIMARY_HOOKED, + /* + * The current work has been linked with the processed chained works, + * and could be also linked with the potential remaining works, which + * means if the processing page is the tail partial page of the work, + * the current work can safely use the whole page (since the next work + * is under control) for in-place decompression, as illustrated below: + * ________________________________________________________________ + * | tail (partial) page | head (partial) page | + * | (of the current work) | (of the previous work) | + * | PRIMARY_FOLLOWED or | | + * |_____PRIMARY_HOOKED____|____________PRIMARY_FOLLOWED____________| + * + * [ (*) the above page can be used for the current work itself. ] */ Z_EROFS_VLE_WORK_PRIMARY_FOLLOWED, Z_EROFS_VLE_WORK_MAX @@ -309,10 +324,10 @@ static int z_erofs_vle_work_add_page( return ret ? 0 : -EAGAIN; } -static inline bool try_to_claim_workgroup( - struct z_erofs_vle_workgroup *grp, - z_erofs_vle_owned_workgrp_t *owned_head, - bool *hosted) +static enum z_erofs_vle_work_role +try_to_claim_workgroup(struct z_erofs_vle_workgroup *grp, + z_erofs_vle_owned_workgrp_t *owned_head, + bool *hosted) { DBG_BUGON(*hosted == true); @@ -326,6 +341,9 @@ retry: *owned_head = &grp->next; *hosted = true; + /* lucky, I am the followee :) */ + return Z_EROFS_VLE_WORK_PRIMARY_FOLLOWED; + } else if (grp->next == Z_EROFS_VLE_WORKGRP_TAIL) { /* * type 2, link to the end of a existing open chain, @@ -335,12 +353,11 @@ retry: if (cmpxchg(&grp->next, Z_EROFS_VLE_WORKGRP_TAIL, *owned_head) != Z_EROFS_VLE_WORKGRP_TAIL) goto retry; - *owned_head = Z_EROFS_VLE_WORKGRP_TAIL; - } else - return false; /* :( better luck next time */ + return Z_EROFS_VLE_WORK_PRIMARY_HOOKED; + } - return true; /* lucky, I am the followee :) */ + return Z_EROFS_VLE_WORK_PRIMARY; /* :( better luck next time */ } struct z_erofs_vle_work_finder { @@ -418,12 +435,9 @@ z_erofs_vle_work_lookup(const struct z_erofs_vle_work_finder *f) *f->hosted = false; if (!primary) *f->role = Z_EROFS_VLE_WORK_SECONDARY; - /* claim the workgroup if possible */ - else if (try_to_claim_workgroup(grp, f->owned_head, f->hosted)) - *f->role = Z_EROFS_VLE_WORK_PRIMARY_FOLLOWED; - else - *f->role = Z_EROFS_VLE_WORK_PRIMARY; - + else /* claim the workgroup if possible */ + *f->role = try_to_claim_workgroup(grp, f->owned_head, + f->hosted); return work; } @@ -487,6 +501,9 @@ z_erofs_vle_work_register(const struct z_erofs_vle_work_finder *f, return work; } +#define builder_is_hooked(builder) \ + ((builder)->role >= Z_EROFS_VLE_WORK_PRIMARY_HOOKED) + #define builder_is_followed(builder) \ ((builder)->role >= Z_EROFS_VLE_WORK_PRIMARY_FOLLOWED) @@ -680,7 +697,7 @@ static int z_erofs_do_read_page(struct z_erofs_vle_frontend *fe, struct z_erofs_vle_work_builder *const builder = &fe->builder; const loff_t offset = page_offset(page); - bool tight = builder_is_followed(builder); + bool tight = builder_is_hooked(builder); struct z_erofs_vle_work *work = builder->work; enum z_erofs_cache_alloctype cache_strategy; @@ -739,7 +756,7 @@ restart_now: map->m_plen / PAGE_SIZE, cache_strategy, page_pool, GFP_KERNEL); - tight &= builder_is_followed(builder); + tight &= builder_is_hooked(builder); work = builder->work; hitted: cur = end - min_t(unsigned int, offset + end - map->m_la, end); @@ -754,6 +771,9 @@ hitted: (tight ? Z_EROFS_PAGE_TYPE_EXCLUSIVE : Z_EROFS_VLE_PAGE_TYPE_TAIL_SHARED)); + if (cur) + tight &= builder_is_followed(builder); + retry: err = z_erofs_vle_work_add_page(builder, page, page_type); /* should allocate an additional staging page for pagevec */ |