diff options
| -rw-r--r-- | Documentation/powerpc/cxlflash.txt | 42 | ||||
| -rw-r--r-- | drivers/scsi/cxlflash/superpipe.c | 71 | ||||
| -rw-r--r-- | drivers/scsi/cxlflash/vlun.c | 13 | ||||
| -rw-r--r-- | include/uapi/scsi/cxlflash_ioctl.h | 19 |
4 files changed, 73 insertions, 72 deletions
diff --git a/Documentation/powerpc/cxlflash.txt b/Documentation/powerpc/cxlflash.txt index 4202d1b..f4c1190 100644 --- a/Documentation/powerpc/cxlflash.txt +++ b/Documentation/powerpc/cxlflash.txt @@ -171,11 +171,30 @@ DK_CXLFLASH_ATTACH destroyed, the tokens are to be considered stale and subsequent usage will result in errors. + - A valid adapter file descriptor (fd2 >= 0) is only returned on + the initial attach for a context. Subsequent attaches to an + existing context (DK_CXLFLASH_ATTACH_REUSE_CONTEXT flag present) + do not provide the adapter file descriptor as it was previously + made known to the application. + - When a context is no longer needed, the user shall detach from - the context via the DK_CXLFLASH_DETACH ioctl. + the context via the DK_CXLFLASH_DETACH ioctl. When this ioctl + returns with a valid adapter file descriptor and the return flag + DK_CXLFLASH_APP_CLOSE_ADAP_FD is present, the application _must_ + close the adapter file descriptor following a successful detach. + + - When this ioctl returns with a valid fd2 and the return flag + DK_CXLFLASH_APP_CLOSE_ADAP_FD is present, the application _must_ + close fd2 in the following circumstances: + + + Following a successful detach of the last user of the context + + Following a successful recovery on the context's original fd2 + + In the child process of a fork(), following a clone ioctl, + on the fd2 associated with the source context - - A close on fd2 will invalidate the tokens. This operation is not - required by the user. + - At any time, a close on fd2 will invalidate the tokens. Applications + should exercise caution to only close fd2 when appropriate (outlined + in the previous bullet) to avoid premature loss of I/O. DK_CXLFLASH_USER_DIRECT ----------------------- @@ -254,6 +273,10 @@ DK_CXLFLASH_DETACH success, all "tokens" which had been provided to the user from the DK_CXLFLASH_ATTACH onward are no longer valid. + When the DK_CXLFLASH_APP_CLOSE_ADAP_FD flag was returned on a successful + attach, the application _must_ close the fd2 associated with the context + following the detach of the final user of the context. + DK_CXLFLASH_VLUN_CLONE ---------------------- This ioctl is responsible for cloning a previously created @@ -261,7 +284,7 @@ DK_CXLFLASH_VLUN_CLONE support maintaining user space access to storage after a process forks. Upon success, the child process (which invoked the ioctl) will have access to the same LUNs via the same resource handle(s) - and fd2 as the parent, but under a different context. + as the parent, but under a different context. Context sharing across processes is not supported with CXL and therefore each fork must be met with establishing a new context @@ -275,6 +298,12 @@ DK_CXLFLASH_VLUN_CLONE translation tables are copied from the parent context to the child's and then synced with the AFU. + When the DK_CXLFLASH_APP_CLOSE_ADAP_FD flag was returned on a successful + attach, the application _must_ close the fd2 associated with the source + context (still resident/accessible in the parent process) following the + clone. This is to avoid a stale entry in the file descriptor table of the + child process. + DK_CXLFLASH_VERIFY ------------------ This ioctl is used to detect various changes such as the capacity of @@ -309,6 +338,11 @@ DK_CXLFLASH_RECOVER_AFU at which time the context/resources they held will be freed as part of the release fop. + When the DK_CXLFLASH_APP_CLOSE_ADAP_FD flag was returned on a successful + attach, the application _must_ unmap and close the fd2 associated with the + original context following this ioctl returning success and indicating that + the context was recovered (DK_CXLFLASH_RECOVER_AFU_CONTEXT_RESET). + DK_CXLFLASH_MANAGE_LUN ---------------------- This ioctl is used to switch a LUN from a mode where it is available diff --git a/drivers/scsi/cxlflash/superpipe.c b/drivers/scsi/cxlflash/superpipe.c index be7522a..b3bb90d 100644 --- a/drivers/scsi/cxlflash/superpipe.c +++ b/drivers/scsi/cxlflash/superpipe.c @@ -825,7 +825,6 @@ static void remove_context(struct kref *kref) { struct ctx_info *ctxi = container_of(kref, struct ctx_info, kref); struct cxlflash_cfg *cfg = ctxi->cfg; - int lfd; u64 ctxid = DECODE_CTXID(ctxi->ctxid); /* Remove context from table/error list */ @@ -842,19 +841,7 @@ static void remove_context(struct kref *kref) mutex_unlock(&ctxi->mutex); /* Context now completely uncoupled/unreachable */ - lfd = ctxi->lfd; destroy_context(cfg, ctxi); - - /* - * As a last step, clean up external resources when not - * already on an external cleanup thread, i.e.: close(adap_fd). - * - * NOTE: this will free up the context from the CXL services, - * allowing it to dole out the same context_id on a future - * (or even currently in-flight) disk_attach operation. - */ - if (lfd != -1) - sys_close(lfd); } /** @@ -949,34 +936,18 @@ static int cxlflash_disk_detach(struct scsi_device *sdev, * * This routine is the release handler for the fops registered with * the CXL services on an initial attach for a context. It is called - * when a close is performed on the adapter file descriptor returned - * to the user. Programmatically, the user is not required to perform - * the close, as it is handled internally via the detach ioctl when - * a context is being removed. Note that nothing prevents the user - * from performing a close, but the user should be aware that doing - * so is considered catastrophic and subsequent usage of the superpipe - * API with previously saved off tokens will fail. + * when a close (explicity by the user or as part of a process tear + * down) is performed on the adapter file descriptor returned to the + * user. The user should be aware that explicitly performing a close + * considered catastrophic and subsequent usage of the superpipe API + * with previously saved off tokens will fail. * - * When initiated from an external close (either by the user or via - * a process tear down), the routine derives the context reference - * and calls detach for each LUN associated with the context. The - * final detach operation will cause the context itself to be freed. - * Note that the saved off lfd is reset prior to calling detach to - * signify that the final detach should not perform a close. - * - * When initiated from a detach operation as part of the tear down - * of a context, the context is first completely freed and then the - * close is performed. This routine will fail to derive the context - * reference (due to the context having already been freed) and then - * call into the CXL release entry point. - * - * Thus, with exception to when the CXL process element (context id) - * lookup fails (a case that should theoretically never occur), every - * call into this routine results in a complete freeing of a context. - * - * As part of the detach, all per-context resources associated with the LUN - * are cleaned up. When detaching the last LUN for a context, the context - * itself is cleaned up and released. + * This routine derives the context reference and calls detach for + * each LUN associated with the context.The final detach operation + * causes the context itself to be freed. With exception to when the + * CXL process element (context id) lookup fails (a case that should + * theoretically never occur), every call into this routine results + * in a complete freeing of a context. * * Return: 0 on success */ @@ -1014,11 +985,8 @@ static int cxlflash_cxl_release(struct inode *inode, struct file *file) goto out; } - dev_dbg(dev, "%s: close(%d) for context %d\n", - __func__, ctxi->lfd, ctxid); + dev_dbg(dev, "%s: close for context %d\n", __func__, ctxid); - /* Reset the file descriptor to indicate we're on a close() thread */ - ctxi->lfd = -1; detach.context_id = ctxi->ctxid; list_for_each_entry_safe(lun_access, t, &ctxi->luns, list) _cxlflash_disk_detach(lun_access->sdev, ctxi, &detach); @@ -1391,7 +1359,6 @@ static int cxlflash_disk_attach(struct scsi_device *sdev, __func__, rctxid); kref_get(&ctxi->kref); list_add(&lun_access->list, &ctxi->luns); - fd = ctxi->lfd; goto out_attach; } @@ -1461,7 +1428,11 @@ static int cxlflash_disk_attach(struct scsi_device *sdev, fd_install(fd, file); out_attach: - attach->hdr.return_flags = 0; + if (fd != -1) + attach->hdr.return_flags = DK_CXLFLASH_APP_CLOSE_ADAP_FD; + else + attach->hdr.return_flags = 0; + attach->context_id = ctxi->ctxid; attach->block_size = gli->blk_len; attach->mmio_size = sizeof(afu->afu_map->hosts[0].harea); @@ -1526,7 +1497,7 @@ static int recover_context(struct cxlflash_cfg *cfg, struct ctx_info *ctxi) { struct device *dev = &cfg->dev->dev; int rc = 0; - int old_fd, fd = -1; + int fd = -1; int ctxid = -1; struct file *file; struct cxl_context *ctx; @@ -1574,7 +1545,6 @@ static int recover_context(struct cxlflash_cfg *cfg, struct ctx_info *ctxi) * No error paths after this point. Once the fd is installed it's * visible to user space and can't be undone safely on this thread. */ - old_fd = ctxi->lfd; ctxi->ctxid = ENCODE_CTXID(ctxi, ctxid); ctxi->lfd = fd; ctxi->ctx = ctx; @@ -1593,9 +1563,6 @@ static int recover_context(struct cxlflash_cfg *cfg, struct ctx_info *ctxi) cfg->ctx_tbl[ctxid] = ctxi; mutex_unlock(&cfg->ctx_tbl_list_mutex); fd_install(fd, file); - - /* Release the original adapter fd and associated CXL resources */ - sys_close(old_fd); out: dev_dbg(dev, "%s: returning ctxid=%d fd=%d rc=%d\n", __func__, ctxid, fd, rc); @@ -1707,7 +1674,7 @@ retry_recover: recover->context_id = ctxi->ctxid; recover->adap_fd = ctxi->lfd; recover->mmio_size = sizeof(afu->afu_map->hosts[0].harea); - recover->hdr.return_flags |= + recover->hdr.return_flags = DK_CXLFLASH_APP_CLOSE_ADAP_FD | DK_CXLFLASH_RECOVER_AFU_CONTEXT_RESET; goto out; } diff --git a/drivers/scsi/cxlflash/vlun.c b/drivers/scsi/cxlflash/vlun.c index 50f8e93..90c5d7f 100644 --- a/drivers/scsi/cxlflash/vlun.c +++ b/drivers/scsi/cxlflash/vlun.c @@ -1135,14 +1135,13 @@ int cxlflash_disk_clone(struct scsi_device *sdev, ctxid_dst = DECODE_CTXID(clone->context_id_dst), rctxid_src = clone->context_id_src, rctxid_dst = clone->context_id_dst; - int adap_fd_src = clone->adap_fd_src; int i, j; int rc = 0; bool found; LIST_HEAD(sidecar); - pr_debug("%s: ctxid_src=%llu ctxid_dst=%llu adap_fd_src=%d\n", - __func__, ctxid_src, ctxid_dst, adap_fd_src); + pr_debug("%s: ctxid_src=%llu ctxid_dst=%llu\n", + __func__, ctxid_src, ctxid_dst); /* Do not clone yourself */ if (unlikely(rctxid_src == rctxid_dst)) { @@ -1166,13 +1165,6 @@ int cxlflash_disk_clone(struct scsi_device *sdev, goto out; } - if (unlikely(adap_fd_src != ctxi_src->lfd)) { - pr_debug("%s: Invalid source adapter fd! (%d)\n", - __func__, adap_fd_src); - rc = -EINVAL; - goto out; - } - /* Verify there is no open resource handle in the destination context */ for (i = 0; i < MAX_RHT_PER_CONTEXT; i++) if (ctxi_dst->rht_start[i].nmask != 0) { @@ -1257,7 +1249,6 @@ int cxlflash_disk_clone(struct scsi_device *sdev, out_success: list_splice(&sidecar, &ctxi_dst->luns); - sys_close(adap_fd_src); /* fall through */ out: diff --git a/include/uapi/scsi/cxlflash_ioctl.h b/include/uapi/scsi/cxlflash_ioctl.h index 2302f3c..6bf1f8a 100644 --- a/include/uapi/scsi/cxlflash_ioctl.h +++ b/include/uapi/scsi/cxlflash_ioctl.h @@ -39,19 +39,28 @@ struct dk_cxlflash_hdr { * at this time, this provides future flexibility. */ #define DK_CXLFLASH_ALL_PORTS_ACTIVE 0x0000000000000001ULL +#define DK_CXLFLASH_APP_CLOSE_ADAP_FD 0x0000000000000002ULL /* - * Notes: - * ----- + * General Notes: + * ------------- * The 'context_id' field of all ioctl structures contains the context * identifier for a context in the lower 32-bits (upper 32-bits are not * to be used when identifying a context to the AFU). That said, the value * in its entirety (all 64-bits) is to be treated as an opaque cookie and * should be presented as such when issuing ioctls. + */ + +/* + * DK_CXLFLASH_ATTACH Notes: + * ------------------------ + * Read/write access permissions are specified via the O_RDONLY, O_WRONLY, + * and O_RDWR flags defined in the fcntl.h header file. * - * For DK_CXLFLASH_ATTACH ioctl, user specifies read/write access - * permissions via the O_RDONLY, O_WRONLY, and O_RDWR flags defined in - * the fcntl.h header file. + * A valid adapter file descriptor (fd >= 0) is only returned on the initial + * attach (successful) of a context. When a context is shared(reused), the user + * is expected to already 'know' the adapter file descriptor associated with the + * context. */ #define DK_CXLFLASH_ATTACH_REUSE_CONTEXT 0x8000000000000000ULL |
