block: introduce new block status code type

Currently we use nornal Linux errno values in the block layer, and while
we accept any error a few have overloaded magic meanings.  This patch
instead introduces a new  blk_status_t value that holds block layer specific
status codes and explicitly explains their meaning.  Helpers to convert from
and to the previous special meanings are provided for now, but I suspect
we want to get rid of them in the long run - those drivers that have a
errno input (e.g. networking) usually get errnos that don't know about
the special block layer overloads, and similarly returning them to userspace
will usually return somethings that strictly speaking isn't correct
for file system operations, but that's left as an exercise for later.

For now the set of errors is a very limited set that closely corresponds
to the previous overloaded errno values, but there is some low hanging
fruite to improve it.

blk_status_t (ab)uses the sparse __bitwise annotations to allow for sparse
typechecking, so that we can easily catch places passing the wrong values.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
This commit is contained in:
Christoph Hellwig 2017-06-03 09:38:04 +02:00 committed by Jens Axboe
parent 1be5690984
commit 2a842acab1
76 changed files with 474 additions and 428 deletions

View file

@ -671,7 +671,7 @@ struct ide_port_ops {
void (*init_dev)(ide_drive_t *);
void (*set_pio_mode)(struct hwif_s *, ide_drive_t *);
void (*set_dma_mode)(struct hwif_s *, ide_drive_t *);
int (*reset_poll)(ide_drive_t *);
blk_status_t (*reset_poll)(ide_drive_t *);
void (*pre_reset)(ide_drive_t *);
void (*resetproc)(ide_drive_t *);
void (*maskproc)(ide_drive_t *, int);
@ -1092,7 +1092,7 @@ int generic_ide_ioctl(ide_drive_t *, struct block_device *, unsigned, unsigned l
extern int ide_vlb_clk;
extern int ide_pci_clk;
int ide_end_rq(ide_drive_t *, struct request *, int, unsigned int);
int ide_end_rq(ide_drive_t *, struct request *, blk_status_t, unsigned int);
void ide_kill_rq(ide_drive_t *, struct request *);
void __ide_set_handler(ide_drive_t *, ide_handler_t *, unsigned int);
@ -1123,7 +1123,7 @@ extern int ide_devset_execute(ide_drive_t *drive,
const struct ide_devset *setting, int arg);
void ide_complete_cmd(ide_drive_t *, struct ide_cmd *, u8, u8);
int ide_complete_rq(ide_drive_t *, int, unsigned int);
int ide_complete_rq(ide_drive_t *, blk_status_t, unsigned int);
void ide_tf_readback(ide_drive_t *drive, struct ide_cmd *cmd);
void ide_tf_dump(const char *, struct ide_cmd *);