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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [PATCH v3 7/7] Mini-OS: add read and write support to 9pfsfront
Juergen Gross, le lun. 13 févr. 2023 09:44:12 +0100, a ecrit:
> Add support to read from and write to a file handled by 9pfsfront.
>
> Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
Reviewed-by: Samuel Thibault <samuel.thibault@xxxxxxxxxxxx>
> ---
> V2:
> - add check for max message size
> - return EAGAIN in case no free request got (Samuel Thibault)
> - loop until all data read/written (Samuel Thibault)
> V3:
> - use an exact limit for read/write (Samuel Thibault)
> - log read(write errors (Samuel Thibault)
> ---
> 9pfront.c | 216 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 216 insertions(+)
>
> diff --git a/9pfront.c b/9pfront.c
> index fb2e5669..5da8a365 100644
> --- a/9pfront.c
> +++ b/9pfront.c
> @@ -72,7 +72,10 @@ struct file_9pfs {
> #define P9_CMD_WALK 110
> #define P9_CMD_OPEN 112
> #define P9_CMD_CREATE 114
> +#define P9_CMD_READ 116
> +#define P9_CMD_WRITE 118
> #define P9_CMD_CLUNK 120
> +#define P9_CMD_STAT 124
>
> /* P9 protocol open flags. */
> #define P9_OREAD 0 /* read */
> @@ -88,11 +91,39 @@ struct p9_header {
> uint16_t tag;
> } __attribute__((packed));
>
> +struct p9_stat {
> + uint16_t size;
> + uint16_t type;
> + uint32_t dev;
> + uint8_t qid[P9_QID_SIZE];
> + uint32_t mode;
> + uint32_t atime;
> + uint32_t mtime;
> + uint64_t length;
> + char *name;
> + char *uid;
> + char *gid;
> + char *muid;
> + char *extension;
> + uint32_t n_uid;
> + uint32_t n_gid;
> + uint32_t n_muid;
> +};
> +
> #define P9_VERSION "9P2000.u"
> #define P9_ROOT_FID 0
>
> static unsigned int ftype_9pfs;
>
> +static void free_stat(struct p9_stat *stat)
> +{
> + free(stat->name);
> + free(stat->uid);
> + free(stat->gid);
> + free(stat->muid);
> + free(stat->extension);
> +}
> +
> static unsigned int get_fid(struct dev_9pfs *dev)
> {
> unsigned int fid;
> @@ -181,9 +212,12 @@ static void copy_from_ring(struct dev_9pfs *dev, void
> *data, unsigned int len)
> * Only valid for sending.
> * u: 2 byte unsigned integer (uint16_t)
> * U: 4 byte unsigned integer (uint32_t)
> + * L: 8 byte unsigned integer (uint64_t)
> * S: String (2 byte length + <length> characters)
> * in the rcv_9p() case the data for string is allocated (length omitted,
> * string terminated by a NUL character)
> + * D: Binary data (4 byte length + <length> bytes of data), requires a length
> + * and a buffer pointer parameter.
> * Q: A 13 byte "qid", consisting of 1 byte file type, 4 byte file version
> * and 8 bytes unique file id. Only valid for receiving.
> */
> @@ -192,10 +226,12 @@ static void send_9p(struct dev_9pfs *dev, struct req
> *req, const char *fmt, ...)
> struct p9_header hdr;
> va_list ap, aq;
> const char *f;
> + uint64_t longval;
> uint32_t intval;
> uint16_t shortval;
> uint16_t len;
> uint8_t byte;
> + uint8_t *data;
> char *strval;
>
> hdr.size = sizeof(hdr);
> @@ -221,11 +257,21 @@ static void send_9p(struct dev_9pfs *dev, struct req
> *req, const char *fmt, ...)
> hdr.size += 4;
> intval = va_arg(aq, unsigned int);
> break;
> + case 'L':
> + hdr.size += 8;
> + longval = va_arg(aq, uint64_t);
> + break;
> case 'S':
> hdr.size += 2;
> strval = va_arg(aq, char *);
> hdr.size += strlen(strval);
> break;
> + case 'D':
> + hdr.size += 4;
> + intval = va_arg(aq, unsigned int);
> + hdr.size += intval;
> + data = va_arg(aq, uint8_t *);
> + break;
> default:
> printk("send_9p: unknown format character %c\n", *f);
> break;
> @@ -258,12 +304,22 @@ static void send_9p(struct dev_9pfs *dev, struct req
> *req, const char *fmt, ...)
> intval = va_arg(ap, unsigned int);
> copy_to_ring(dev, &intval, sizeof(intval));
> break;
> + case 'L':
> + longval = va_arg(ap, uint64_t);
> + copy_to_ring(dev, &longval, sizeof(longval));
> + break;
> case 'S':
> strval = va_arg(ap, char *);
> len = strlen(strval);
> copy_to_ring(dev, &len, sizeof(len));
> copy_to_ring(dev, strval, len);
> break;
> + case 'D':
> + intval = va_arg(ap, unsigned int);
> + copy_to_ring(dev, &intval, sizeof(intval));
> + data = va_arg(ap, uint8_t *);
> + copy_to_ring(dev, data, intval);
> + break;
> }
> }
>
> @@ -348,6 +404,8 @@ static void rcv_9p_copy(struct dev_9pfs *dev, struct req
> *req,
> uint32_t err;
> uint16_t *shortval;
> uint32_t *val;
> + uint64_t *longval;
> + uint8_t *data;
> char **strval;
> uint8_t *qval;
>
> @@ -412,6 +470,10 @@ static void rcv_9p_copy(struct dev_9pfs *dev, struct req
> *req,
> val = va_arg(ap, uint32_t *);
> copy_bufs(&buf1, &buf2, &len1, &len2, val, sizeof(*val));
> break;
> + case 'L':
> + longval = va_arg(ap, uint64_t *);
> + copy_bufs(&buf1, &buf2, &len1, &len2, longval, sizeof(*longval));
> + break;
> case 'S':
> strval = va_arg(ap, char **);
> copy_bufs(&buf1, &buf2, &len1, &len2, &len, sizeof(len));
> @@ -419,6 +481,12 @@ static void rcv_9p_copy(struct dev_9pfs *dev, struct req
> *req,
> copy_bufs(&buf1, &buf2, &len1, &len2, *strval, len);
> (*strval)[len] = 0;
> break;
> + case 'D':
> + val = va_arg(ap, uint32_t *);
> + data = va_arg(ap, uint8_t *);
> + copy_bufs(&buf1, &buf2, &len1, &len2, val, sizeof(*val));
> + copy_bufs(&buf1, &buf2, &len1, &len2, data, *val);
> + break;
> case 'Q':
> qval = va_arg(ap, uint8_t *);
> copy_bufs(&buf1, &buf2, &len1, &len2, qval, P9_QID_SIZE);
> @@ -640,6 +708,115 @@ static int p9_create(struct dev_9pfs *dev, uint32_t
> fid, char *path,
> return ret;
> }
>
> +static int p9_stat(struct dev_9pfs *dev, uint32_t fid, struct p9_stat *stat)
> +{
> + struct req *req = get_free_req(dev);
> + int ret;
> +
> + if ( !req )
> + return EAGAIN;
> +
> + memset(stat, 0, sizeof(*stat));
> + req->cmd = P9_CMD_STAT;
> + send_9p(dev, req, "U", fid);
> + rcv_9p(dev, req, "uuUQUUULSSSSSUUU", &stat->size, &stat->type,
> &stat->dev,
> + stat->qid, &stat->mode, &stat->atime, &stat->mtime, &stat->length,
> + &stat->name, &stat->uid, &stat->gid, &stat->muid,
> &stat->extension,
> + &stat->n_uid, &stat->n_gid, &stat->n_muid);
> +
> + ret = req->result;
> +
> + put_free_req(dev, req);
> +
> + return ret;
> +}
> +
> +static int p9_read(struct dev_9pfs *dev, uint32_t fid, uint64_t offset,
> + uint8_t *data, uint32_t len)
> +{
> + struct req *req = get_free_req(dev);
> + int ret = 0;
> + uint32_t count, count_max;
> +
> + if ( !req )
> + {
> + errno = EAGAIN;
> + return -1;
> + }
> + req->cmd = P9_CMD_READ;
> + count_max = dev->msize_max - (sizeof(struct p9_header) +
> sizeof(uint32_t));
> +
> + while ( len )
> + {
> + count = len;
> + if ( count > count_max )
> + count = count_max;
> +
> + send_9p(dev, req, "ULU", fid, offset, count);
> + rcv_9p(dev, req, "D", &count, data);
> +
> + if ( !count )
> + break;
> + if ( req->result )
> + {
> + ret = -1;
> + errno = EIO;
> + printk("9pfs: read got error %d\n", req->result);
> + break;
> + }
> + ret += count;
> + offset += count;
> + data += count;
> + len -= count;
> + }
> +
> + put_free_req(dev, req);
> +
> + return ret;
> +}
> +
> +static int p9_write(struct dev_9pfs *dev, uint32_t fid, uint64_t offset,
> + const uint8_t *data, uint32_t len)
> +{
> + struct req *req = get_free_req(dev);
> + int ret = 0;
> + uint32_t count, count_max;
> +
> + if ( !req )
> + {
> + errno = EAGAIN;
> + return -1;
> + }
> + req->cmd = P9_CMD_WRITE;
> + count_max = dev->msize_max - (sizeof(struct p9_header) +
> sizeof(uint32_t) +
> + sizeof(uint64_t) + sizeof(uint32_t));
> +
> + while ( len )
> + {
> + count = len;
> + if ( count > count_max )
> + count = count_max;
> +
> + send_9p(dev, req, "ULD", fid, offset, count, data);
> + rcv_9p(dev, req, "U", &count);
> + if ( req->result )
> + {
> + ret = -1;
> + errno = EIO;
> + printk("9pfs: write got error %d\n", req->result);
> + break;
> + }
> + ret += count;
> + offset += count;
> + data += count;
> + len -= count;
> + }
> +
> + put_free_req(dev, req);
> +
> + return ret;
> +}
> +
> /*
> * Walk from root <steps> levels with the levels listed in <*paths> as a
> * sequence of names. Returns the number of steps not having been able to
> @@ -731,6 +908,43 @@ static void intr_9pfs(evtchn_port_t port, struct pt_regs
> *regs, void *data)
> wake_up(&dev->waitq);
> }
>
> +static int read_9pfs(struct file *file, void *buf, size_t nbytes)
> +{
> + struct file_9pfs *f9pfs = file->filedata;
> + int ret;
> +
> + ret = p9_read(f9pfs->dev, f9pfs->fid, file->offset, buf, nbytes);
> + if ( ret >= 0 )
> + file->offset += ret;
> +
> + return ret;
> +}
> +
> +static int write_9pfs(struct file *file, const void *buf, size_t nbytes)
> +{
> + struct file_9pfs *f9pfs = file->filedata;
> + struct p9_stat stat;
> + int ret;
> +
> + if ( f9pfs->append )
> + {
> + ret = p9_stat(f9pfs->dev, f9pfs->fid, &stat);
> + free_stat(&stat);
> + if ( ret )
> + {
> + errno = EIO;
> + return -1;
> + }
> + file->offset = stat.length;
> + }
> +
> + ret = p9_write(f9pfs->dev, f9pfs->fid, file->offset, buf, nbytes);
> + if ( ret >= 0 )
> + file->offset += ret;
> +
> + return ret;
> +}
> +
> static int close_9pfs(struct file *file)
> {
> struct file_9pfs *f9pfs = file->filedata;
> @@ -1072,6 +1286,8 @@ void shutdown_9pfront(void *dev)
>
> static const struct file_ops ops_9pfs = {
> .name = "9pfs",
> + .read = read_9pfs,
> + .write = write_9pfs,
> .close = close_9pfs,
> };
>
> --
> 2.35.3
>
--
Samuel
---
Pour une évaluation indépendante, transparente et rigoureuse !
Je soutiens la Commission d'Évaluation de l'Inria.
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