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| author | Jonas Rabenstein <jonas.rabenstein@studium.uni-erlangen.de> | 2019-02-14 01:16:02 +0100 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2019-04-06 11:09:12 -0600 |
| commit | 285599590e2e1f067d56a5855244e95f6303b28f (patch) | |
| tree | 760eab99b46fd81951dd39f1582d6e36aa255f53 /block/sed-opal.c | |
| parent | b2f9c6eb3f5f44d2fded05856f69050d7170eeff (diff) | |
| download | lwn-285599590e2e1f067d56a5855244e95f6303b28f.tar.gz lwn-285599590e2e1f067d56a5855244e95f6303b28f.zip | |
block: sed-opal: split generation of bytestring header and content
Split the header generation from the (normal) memcpy part if a
bytestring is copied into the command buffer. This allows in-place
generation of the bytestring content. For example, copy_from_user may be
used without an intermediate buffer.
Signed-off-by: Jonas Rabenstein <jonas.rabenstein@studium.uni-erlangen.de>
Signed-off-by: David Kozub <zub@linux.fjfi.cvut.cz>
Reviewed-by: Scott Bauer <sbauer@plzdonthack.me>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jon Derrick <jonathan.derrick@intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/sed-opal.c')
| -rw-r--r-- | block/sed-opal.c | 22 |
1 files changed, 14 insertions, 8 deletions
diff --git a/block/sed-opal.c b/block/sed-opal.c index 1f246200b574..ad66d1dc725a 100644 --- a/block/sed-opal.c +++ b/block/sed-opal.c @@ -580,15 +580,11 @@ static void add_token_u64(int *err, struct opal_dev *cmd, u64 number) add_token_u8(err, cmd, number >> (len * 8)); } -static void add_token_bytestring(int *err, struct opal_dev *cmd, - const u8 *bytestring, size_t len) +static u8 *add_bytestring_header(int *err, struct opal_dev *cmd, size_t len) { size_t header_len = 1; bool is_short_atom = true; - if (*err) - return; - if (len & ~SHORT_ATOM_LEN_MASK) { header_len = 2; is_short_atom = false; @@ -596,7 +592,7 @@ static void add_token_bytestring(int *err, struct opal_dev *cmd, if (!can_add(err, cmd, header_len + len)) { pr_debug("Error adding bytestring: end of buffer.\n"); - return; + return NULL; } if (is_short_atom) @@ -604,9 +600,19 @@ static void add_token_bytestring(int *err, struct opal_dev *cmd, else add_medium_atom_header(cmd, true, false, len); - memcpy(&cmd->cmd[cmd->pos], bytestring, len); - cmd->pos += len; + return &cmd->cmd[cmd->pos]; +} +static void add_token_bytestring(int *err, struct opal_dev *cmd, + const u8 *bytestring, size_t len) +{ + u8 *start; + + start = add_bytestring_header(err, cmd, len); + if (!start) + return; + memcpy(start, bytestring, len); + cmd->pos += len; } static int build_locking_range(u8 *buffer, size_t length, u8 lr) |