From 3e8e2e0c8da1f1701a8014543c951c41751791cc Mon Sep 17 00:00:00 2001 From: Artem Bityutskiy Date: Sun, 30 Jan 2011 18:58:32 +0200 Subject: [PATCH] UBIFS: incorporate maximum write size Incorporate maximum write size into the UBIFS description data structure. This patch just introduces new 'c->max_write_size' and 'c->max_write_shift' fields as a preparation for the following patches. Signed-off-by: Artem Bityutskiy --- fs/ubifs/super.c | 19 +++++++++++++++++++ fs/ubifs/ubifs.h | 5 +++++ 2 files changed, 24 insertions(+) diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c index 703a62109cf2..efc327b92f98 100644 --- a/fs/ubifs/super.c +++ b/fs/ubifs/super.c @@ -507,6 +507,8 @@ static int init_constants_early(struct ubifs_info *c) c->half_leb_size = c->leb_size / 2; c->min_io_size = c->di.min_io_size; c->min_io_shift = fls(c->min_io_size) - 1; + c->max_write_size = c->di.max_write_size; + c->max_write_shift = fls(c->max_write_size) - 1; if (c->leb_size < UBIFS_MIN_LEB_SZ) { ubifs_err("too small LEBs (%d bytes), min. is %d bytes", @@ -525,6 +527,18 @@ static int init_constants_early(struct ubifs_info *c) return -EINVAL; } + /* + * Maximum write size has to be greater or equivalent to min. I/O + * size, and be multiple of min. I/O size. + */ + if (c->max_write_size < c->min_io_size || + c->max_write_size % c->min_io_size || + !is_power_of_2(c->max_write_size)) { + ubifs_err("bad write buffer size %d for %d min. I/O unit", + c->max_write_size, c->min_io_size); + return -EINVAL; + } + /* * UBIFS aligns all node to 8-byte boundary, so to make function in * io.c simpler, assume minimum I/O unit size to be 8 bytes if it is @@ -533,6 +547,10 @@ static int init_constants_early(struct ubifs_info *c) if (c->min_io_size < 8) { c->min_io_size = 8; c->min_io_shift = 3; + if (c->max_write_size < c->min_io_size) { + c->max_write_size = c->min_io_size; + c->max_write_shift = c->min_io_shift; + } } c->ref_node_alsz = ALIGN(UBIFS_REF_NODE_SZ, c->min_io_size); @@ -1391,6 +1409,7 @@ static int mount_ubifs(struct ubifs_info *c) dbg_msg("compiled on: " __DATE__ " at " __TIME__); dbg_msg("min. I/O unit size: %d bytes", c->min_io_size); + dbg_msg("max. write size: %d bytes", c->max_write_size); dbg_msg("LEB size: %d bytes (%d KiB)", c->leb_size, c->leb_size >> 10); dbg_msg("data journal heads: %d", diff --git a/fs/ubifs/ubifs.h b/fs/ubifs/ubifs.h index d1823541f987..8b519499f14a 100644 --- a/fs/ubifs/ubifs.h +++ b/fs/ubifs/ubifs.h @@ -1024,6 +1024,9 @@ struct ubifs_debug_info; * * @min_io_size: minimal input/output unit size * @min_io_shift: number of bits in @min_io_size minus one + * @max_write_size: maximum amount of bytes the underlying flash can write at a + * time (MTD write buffer size) + * @max_write_shift: number of bits in @max_write_size minus one * @leb_size: logical eraseblock size in bytes * @half_leb_size: half LEB size * @idx_leb_size: how many bytes of an LEB are effectively available when it is @@ -1270,6 +1273,8 @@ struct ubifs_info { int min_io_size; int min_io_shift; + int max_write_size; + int max_write_shift; int leb_size; int half_leb_size; int idx_leb_size; -- 2.45.2