From fe245c8fcdac339e6b42076c828a6bede3a5e948 Mon Sep 17 00:00:00 2001 From: David Howells Date: Wed, 18 Oct 2023 08:42:18 +0100 Subject: afs: Add comments on abort handling Add some comments on AFS abort code handling in the rotation algorithm and adjust the errors produced to match. Reported-by: Jeffrey E Altman Signed-off-by: David Howells Reviewed-by: Jeffrey Altman cc: Marc Dionne cc: linux-afs@lists.infradead.org --- fs/afs/rotate.c | 101 ++++++++++++++++++++++++++++++++++++++++++++++++++------ 1 file changed, 90 insertions(+), 11 deletions(-) (limited to 'fs/afs') diff --git a/fs/afs/rotate.c b/fs/afs/rotate.c index a840c3588ebb..a3d127953ac6 100644 --- a/fs/afs/rotate.c +++ b/fs/afs/rotate.c @@ -13,6 +13,7 @@ #include #include "internal.h" #include "afs_fs.h" +#include "protocol_uae.h" /* * Begin iteration through a server list, starting with the vnode's last used @@ -143,6 +144,11 @@ bool afs_select_fileserver(struct afs_operation *op) case -ECONNABORTED: /* The far side rejected the operation on some grounds. This * might involve the server being busy or the volume having been moved. + * + * Note that various V* errors should not be sent to a cache manager + * by a fileserver as they should be translated to more modern UAE* + * errors instead. IBM AFS and OpenAFS fileservers, however, do leak + * these abort codes. */ switch (op->ac.abort_code) { case VNOVOL: @@ -150,6 +156,11 @@ bool afs_select_fileserver(struct afs_operation *op) * - May indicate that the VL is wrong - retry once and compare * the results. * - May indicate that the fileserver couldn't attach to the vol. + * - The volume might have been temporarily removed so that it can + * be replaced by a volume restore. "vos" might have ended one + * transaction and has yet to create the next. + * - The volume might not be blessed or might not be in-service + * (administrative action). */ if (op->flags & AFS_OPERATION_VNOVOL) { op->error = -EREMOTEIO; @@ -183,16 +194,56 @@ bool afs_select_fileserver(struct afs_operation *op) _leave(" = t [vnovol]"); return true; - case VSALVAGE: /* TODO: Should this return an error or iterate? */ case VVOLEXISTS: - case VNOSERVICE: case VONLINE: - case VDISKFULL: - case VOVERQUOTA: - op->error = afs_abort_to_error(op->ac.abort_code); + /* These should not be returned from the fileserver. */ + pr_warn("Fileserver returned unexpected abort %d\n", + op->ac.abort_code); + op->error = -EREMOTEIO; + goto next_server; + + case VNOSERVICE: + /* Prior to AFS 3.2 VNOSERVICE was returned from the fileserver + * if the volume was neither in-service nor administratively + * blessed. All usage was replaced by VNOVOL because AFS 3.1 and + * earlier cache managers did not handle VNOSERVICE and assumed + * it was the client OSes errno 105. + * + * Starting with OpenAFS 1.4.8 VNOSERVICE was repurposed as the + * fileserver idle dead time error which was sent in place of + * RX_CALL_TIMEOUT (-3). The error was intended to be sent if the + * fileserver took too long to send a reply to the client. + * RX_CALL_TIMEOUT would have caused the cache manager to mark the + * server down whereas VNOSERVICE since AFS 3.2 would cause cache + * manager to temporarily (up to 15 minutes) mark the volume + * instance as unusable. + * + * The idle dead logic resulted in cache inconsistency since a + * state changing call that the cache manager assumed was dead + * could still be processed to completion by the fileserver. This + * logic was removed in OpenAFS 1.8.0 and VNOSERVICE is no longer + * returned. However, many 1.4.8 through 1.6.24 fileservers are + * still in existence. + * + * AuriStorFS fileservers have never returned VNOSERVICE. + * + * VNOSERVICE should be treated as an alias for RX_CALL_TIMEOUT. + */ + case RX_CALL_TIMEOUT: + op->error = -ETIMEDOUT; goto next_server; + case VSALVAGING: /* This error should not be leaked to cache managers + * but is from OpenAFS demand attach fileservers. + * It should be treated as an alias for VOFFLINE. + */ + case VSALVAGE: /* VSALVAGE should be treated as a synonym of VOFFLINE */ case VOFFLINE: + /* The volume is in use by the volserver or another volume utility + * for an operation that might alter the contents. The volume is + * expected to come back but it might take a long time (could be + * days). + */ if (!test_and_set_bit(AFS_VOLUME_OFFLINE, &op->volume->flags)) { afs_busy(op->volume, op->ac.abort_code); clear_bit(AFS_VOLUME_BUSY, &op->volume->flags); @@ -207,11 +258,20 @@ bool afs_select_fileserver(struct afs_operation *op) } goto busy; - case VSALVAGING: - case VRESTARTING: + case VRESTARTING: /* The fileserver is either shutting down or starting up. */ case VBUSY: - /* Retry after going round all the servers unless we - * have a file lock we need to maintain. + /* The volume is in use by the volserver or another volume + * utility for an operation that is not expected to alter the + * contents of the volume. VBUSY does not need to be returned + * for a ROVOL or BACKVOL bound to an ITBusy volserver + * transaction. The fileserver is permitted to continue serving + * content from ROVOLs and BACKVOLs during an ITBusy transaction + * because the content will not change. However, many fileserver + * releases do return VBUSY for ROVOL and BACKVOL instances under + * many circumstances. + * + * Retry after going round all the servers unless we have a file + * lock we need to maintain. */ if (op->flags & AFS_OPERATION_NO_VSLEEP) { op->error = -EBUSY; @@ -226,7 +286,7 @@ bool afs_select_fileserver(struct afs_operation *op) if (!afs_sleep_and_retry(op)) goto failed; - /* Retry with same server & address */ + /* Retry with same server & address */ _leave(" = t [vbusy]"); return true; } @@ -270,10 +330,29 @@ bool afs_select_fileserver(struct afs_operation *op) goto restart_from_beginning; + case VDISKFULL: + case UAENOSPC: + /* The partition is full. Only applies to RWVOLs. + * Translate locally and return ENOSPC. + * No replicas to failover to. + */ + op->error = -ENOSPC; + goto failed_but_online; + + case VOVERQUOTA: + case UAEDQUOT: + /* Volume is full. Only applies to RWVOLs. + * Translate locally and return EDQUOT. + * No replicas to failover to. + */ + op->error = -EDQUOT; + goto failed_but_online; + default: + op->error = afs_abort_to_error(op->ac.abort_code); + failed_but_online: clear_bit(AFS_VOLUME_OFFLINE, &op->volume->flags); clear_bit(AFS_VOLUME_BUSY, &op->volume->flags); - op->error = afs_abort_to_error(op->ac.abort_code); goto failed; } -- cgit v1.2.3