diff options
Diffstat (limited to 'drivers/md')
| -rw-r--r-- | drivers/md/dm-exception-store.c | 102 |
1 files changed, 68 insertions, 34 deletions
diff --git a/drivers/md/dm-exception-store.c b/drivers/md/dm-exception-store.c index 769ab677f8e..fe6cef8df20 100644 --- a/drivers/md/dm-exception-store.c +++ b/drivers/md/dm-exception-store.c @@ -105,6 +105,11 @@ struct pstore { void *area; /* + * An area of zeros used to clear the next area. + */ + void *zero_area; + + /* * Used to keep track of which metadata area the data in * 'chunk' refers to. */ @@ -149,6 +154,13 @@ static int alloc_area(struct pstore *ps) if (!ps->area) return r; + ps->zero_area = vmalloc(len); + if (!ps->zero_area) { + vfree(ps->area); + return r; + } + memset(ps->zero_area, 0, len); + return 0; } @@ -156,6 +168,8 @@ static void free_area(struct pstore *ps) { vfree(ps->area); ps->area = NULL; + vfree(ps->zero_area); + ps->zero_area = NULL; } struct mdata_req { @@ -220,25 +234,41 @@ static chunk_t area_location(struct pstore *ps, chunk_t area) * Read or write a metadata area. Remembering to skip the first * chunk which holds the header. */ -static int area_io(struct pstore *ps, chunk_t area, int rw) +static int area_io(struct pstore *ps, int rw) { int r; chunk_t chunk; - chunk = area_location(ps, area); + chunk = area_location(ps, ps->current_area); r = chunk_io(ps, chunk, rw, 0); if (r) return r; - ps->current_area = area; return 0; } -static int zero_area(struct pstore *ps, chunk_t area) +static void zero_memory_area(struct pstore *ps) { memset(ps->area, 0, ps->snap->chunk_size << SECTOR_SHIFT); - return area_io(ps, area, WRITE); +} + +static int zero_disk_area(struct pstore *ps, chunk_t area) +{ + struct dm_io_region where = { + .bdev = ps->snap->cow->bdev, + .sector = ps->snap->chunk_size * area_location(ps, area), + .count = ps->snap->chunk_size, + }; + struct dm_io_request io_req = { + .bi_rw = WRITE, + .mem.type = DM_IO_VMA, + .mem.ptr.vma = ps->zero_area, + .client = ps->io_client, + .notify.fn = NULL, + }; + + return dm_io(&io_req, 1, &where, NULL); } static int read_header(struct pstore *ps, int *new_snapshot) @@ -411,15 +441,14 @@ static int insert_exceptions(struct pstore *ps, int *full) static int read_exceptions(struct pstore *ps) { - chunk_t area; int r, full = 1; /* * Keeping reading chunks and inserting exceptions until * we find a partially full area. */ - for (area = 0; full; area++) { - r = area_io(ps, area, READ); + for (ps->current_area = 0; full; ps->current_area++) { + r = area_io(ps, READ); if (r) return r; @@ -428,6 +457,8 @@ static int read_exceptions(struct pstore *ps) return r; } + ps->current_area--; + return 0; } @@ -486,12 +517,13 @@ static int persistent_read_metadata(struct exception_store *store) return r; } - r = zero_area(ps, 0); + ps->current_area = 0; + zero_memory_area(ps); + r = zero_disk_area(ps, 0); if (r) { - DMWARN("zero_area(0) failed"); + DMWARN("zero_disk_area(0) failed"); return r; } - } else { /* * Sanity checks. @@ -551,7 +583,6 @@ static void persistent_commit(struct exception_store *store, void (*callback) (void *, int success), void *callback_context) { - int r; unsigned int i; struct pstore *ps = get_info(store); struct disk_exception de; @@ -572,33 +603,36 @@ static void persistent_commit(struct exception_store *store, cb->context = callback_context; /* - * If there are no more exceptions in flight, or we have - * filled this metadata area we commit the exceptions to - * disk. + * If there are exceptions in flight and we have not yet + * filled this metadata area there's nothing more to do. */ - if (atomic_dec_and_test(&ps->pending_count) || - (ps->current_committed == ps->exceptions_per_area)) { - r = area_io(ps, ps->current_area, WRITE); - if (r) - ps->valid = 0; + if (!atomic_dec_and_test(&ps->pending_count) && + (ps->current_committed != ps->exceptions_per_area)) + return; - /* - * Have we completely filled the current area ? - */ - if (ps->current_committed == ps->exceptions_per_area) { - ps->current_committed = 0; - r = zero_area(ps, ps->current_area + 1); - if (r) - ps->valid = 0; - } + /* + * Commit exceptions to disk. + */ + if (area_io(ps, WRITE)) + ps->valid = 0; - for (i = 0; i < ps->callback_count; i++) { - cb = ps->callbacks + i; - cb->callback(cb->context, r == 0 ? 1 : 0); - } + /* + * Advance to the next area if this one is full. + */ + if (ps->current_committed == ps->exceptions_per_area) { + if (zero_disk_area(ps, ps->current_area + 1)) + ps->valid = 0; + ps->current_committed = 0; + ps->current_area++; + zero_memory_area(ps); + } - ps->callback_count = 0; + for (i = 0; i < ps->callback_count; i++) { + cb = ps->callbacks + i; + cb->callback(cb->context, ps->valid); } + + ps->callback_count = 0; } static void persistent_drop(struct exception_store *store) |