diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /fs/afs/vlocation.c | |
download | blackbird-op-linux-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.gz blackbird-op-linux-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.zip |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'fs/afs/vlocation.c')
-rw-r--r-- | fs/afs/vlocation.c | 954 |
1 files changed, 954 insertions, 0 deletions
diff --git a/fs/afs/vlocation.c b/fs/afs/vlocation.c new file mode 100644 index 000000000000..eced20618ecc --- /dev/null +++ b/fs/afs/vlocation.c @@ -0,0 +1,954 @@ +/* vlocation.c: volume location management + * + * Copyright (C) 2002 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/init.h> +#include <linux/slab.h> +#include <linux/fs.h> +#include <linux/pagemap.h> +#include "volume.h" +#include "cell.h" +#include "cmservice.h" +#include "fsclient.h" +#include "vlclient.h" +#include "kafstimod.h" +#include <rxrpc/connection.h> +#include "internal.h" + +#define AFS_VLDB_TIMEOUT HZ*1000 + +static void afs_vlocation_update_timer(struct afs_timer *timer); +static void afs_vlocation_update_attend(struct afs_async_op *op); +static void afs_vlocation_update_discard(struct afs_async_op *op); +static void __afs_put_vlocation(struct afs_vlocation *vlocation); + +static void __afs_vlocation_timeout(struct afs_timer *timer) +{ + struct afs_vlocation *vlocation = + list_entry(timer, struct afs_vlocation, timeout); + + _debug("VL TIMEOUT [%s{u=%d}]", + vlocation->vldb.name, atomic_read(&vlocation->usage)); + + afs_vlocation_do_timeout(vlocation); +} + +static const struct afs_timer_ops afs_vlocation_timer_ops = { + .timed_out = __afs_vlocation_timeout, +}; + +static const struct afs_timer_ops afs_vlocation_update_timer_ops = { + .timed_out = afs_vlocation_update_timer, +}; + +static const struct afs_async_op_ops afs_vlocation_update_op_ops = { + .attend = afs_vlocation_update_attend, + .discard = afs_vlocation_update_discard, +}; + +static LIST_HEAD(afs_vlocation_update_pendq); /* queue of VLs awaiting update */ +static struct afs_vlocation *afs_vlocation_update; /* VL currently being updated */ +static DEFINE_SPINLOCK(afs_vlocation_update_lock); /* lock guarding update queue */ + +#ifdef AFS_CACHING_SUPPORT +static cachefs_match_val_t afs_vlocation_cache_match(void *target, + const void *entry); +static void afs_vlocation_cache_update(void *source, void *entry); + +struct cachefs_index_def afs_vlocation_cache_index_def = { + .name = "vldb", + .data_size = sizeof(struct afs_cache_vlocation), + .keys[0] = { CACHEFS_INDEX_KEYS_ASCIIZ, 64 }, + .match = afs_vlocation_cache_match, + .update = afs_vlocation_cache_update, +}; +#endif + +/*****************************************************************************/ +/* + * iterate through the VL servers in a cell until one of them admits knowing + * about the volume in question + * - caller must have cell->vl_sem write-locked + */ +static int afs_vlocation_access_vl_by_name(struct afs_vlocation *vlocation, + const char *name, + unsigned namesz, + struct afs_cache_vlocation *vldb) +{ + struct afs_server *server = NULL; + struct afs_cell *cell = vlocation->cell; + int count, ret; + + _enter("%s,%*.*s,%u", cell->name, namesz, namesz, name, namesz); + + ret = -ENOMEDIUM; + for (count = cell->vl_naddrs; count > 0; count--) { + _debug("CellServ[%hu]: %08x", + cell->vl_curr_svix, + cell->vl_addrs[cell->vl_curr_svix].s_addr); + + /* try and create a server */ + ret = afs_server_lookup(cell, + &cell->vl_addrs[cell->vl_curr_svix], + &server); + switch (ret) { + case 0: + break; + case -ENOMEM: + case -ENONET: + goto out; + default: + goto rotate; + } + + /* attempt to access the VL server */ + ret = afs_rxvl_get_entry_by_name(server, name, namesz, vldb); + switch (ret) { + case 0: + afs_put_server(server); + goto out; + case -ENOMEM: + case -ENONET: + case -ENETUNREACH: + case -EHOSTUNREACH: + case -ECONNREFUSED: + down_write(&server->sem); + if (server->vlserver) { + rxrpc_put_connection(server->vlserver); + server->vlserver = NULL; + } + up_write(&server->sem); + afs_put_server(server); + if (ret == -ENOMEM || ret == -ENONET) + goto out; + goto rotate; + case -ENOMEDIUM: + afs_put_server(server); + goto out; + default: + afs_put_server(server); + ret = -ENOMEDIUM; + goto rotate; + } + + /* rotate the server records upon lookup failure */ + rotate: + cell->vl_curr_svix++; + cell->vl_curr_svix %= cell->vl_naddrs; + } + + out: + _leave(" = %d", ret); + return ret; + +} /* end afs_vlocation_access_vl_by_name() */ + +/*****************************************************************************/ +/* + * iterate through the VL servers in a cell until one of them admits knowing + * about the volume in question + * - caller must have cell->vl_sem write-locked + */ +static int afs_vlocation_access_vl_by_id(struct afs_vlocation *vlocation, + afs_volid_t volid, + afs_voltype_t voltype, + struct afs_cache_vlocation *vldb) +{ + struct afs_server *server = NULL; + struct afs_cell *cell = vlocation->cell; + int count, ret; + + _enter("%s,%x,%d,", cell->name, volid, voltype); + + ret = -ENOMEDIUM; + for (count = cell->vl_naddrs; count > 0; count--) { + _debug("CellServ[%hu]: %08x", + cell->vl_curr_svix, + cell->vl_addrs[cell->vl_curr_svix].s_addr); + + /* try and create a server */ + ret = afs_server_lookup(cell, + &cell->vl_addrs[cell->vl_curr_svix], + &server); + switch (ret) { + case 0: + break; + case -ENOMEM: + case -ENONET: + goto out; + default: + goto rotate; + } + + /* attempt to access the VL server */ + ret = afs_rxvl_get_entry_by_id(server, volid, voltype, vldb); + switch (ret) { + case 0: + afs_put_server(server); + goto out; + case -ENOMEM: + case -ENONET: + case -ENETUNREACH: + case -EHOSTUNREACH: + case -ECONNREFUSED: + down_write(&server->sem); + if (server->vlserver) { + rxrpc_put_connection(server->vlserver); + server->vlserver = NULL; + } + up_write(&server->sem); + afs_put_server(server); + if (ret == -ENOMEM || ret == -ENONET) + goto out; + goto rotate; + case -ENOMEDIUM: + afs_put_server(server); + goto out; + default: + afs_put_server(server); + ret = -ENOMEDIUM; + goto rotate; + } + + /* rotate the server records upon lookup failure */ + rotate: + cell->vl_curr_svix++; + cell->vl_curr_svix %= cell->vl_naddrs; + } + + out: + _leave(" = %d", ret); + return ret; + +} /* end afs_vlocation_access_vl_by_id() */ + +/*****************************************************************************/ +/* + * lookup volume location + * - caller must have cell->vol_sem write-locked + * - iterate through the VL servers in a cell until one of them admits knowing + * about the volume in question + * - lookup in the local cache if not able to find on the VL server + * - insert/update in the local cache if did get a VL response + */ +int afs_vlocation_lookup(struct afs_cell *cell, + const char *name, + unsigned namesz, + struct afs_vlocation **_vlocation) +{ + struct afs_cache_vlocation vldb; + struct afs_vlocation *vlocation; + afs_voltype_t voltype; + afs_volid_t vid; + int active = 0, ret; + + _enter("{%s},%*.*s,%u,", cell->name, namesz, namesz, name, namesz); + + if (namesz > sizeof(vlocation->vldb.name)) { + _leave(" = -ENAMETOOLONG"); + return -ENAMETOOLONG; + } + + /* search the cell's active list first */ + list_for_each_entry(vlocation, &cell->vl_list, link) { + if (namesz < sizeof(vlocation->vldb.name) && + vlocation->vldb.name[namesz] != '\0') + continue; + + if (memcmp(vlocation->vldb.name, name, namesz) == 0) + goto found_in_memory; + } + + /* search the cell's graveyard list second */ + spin_lock(&cell->vl_gylock); + list_for_each_entry(vlocation, &cell->vl_graveyard, link) { + if (namesz < sizeof(vlocation->vldb.name) && + vlocation->vldb.name[namesz] != '\0') + continue; + + if (memcmp(vlocation->vldb.name, name, namesz) == 0) + goto found_in_graveyard; + } + spin_unlock(&cell->vl_gylock); + + /* not in the cell's in-memory lists - create a new record */ + vlocation = kmalloc(sizeof(struct afs_vlocation), GFP_KERNEL); + if (!vlocation) + return -ENOMEM; + + memset(vlocation, 0, sizeof(struct afs_vlocation)); + atomic_set(&vlocation->usage, 1); + INIT_LIST_HEAD(&vlocation->link); + rwlock_init(&vlocation->lock); + memcpy(vlocation->vldb.name, name, namesz); + + afs_timer_init(&vlocation->timeout, &afs_vlocation_timer_ops); + afs_timer_init(&vlocation->upd_timer, &afs_vlocation_update_timer_ops); + afs_async_op_init(&vlocation->upd_op, &afs_vlocation_update_op_ops); + + afs_get_cell(cell); + vlocation->cell = cell; + + list_add_tail(&vlocation->link, &cell->vl_list); + +#ifdef AFS_CACHING_SUPPORT + /* we want to store it in the cache, plus it might already be + * encached */ + cachefs_acquire_cookie(cell->cache, + &afs_volume_cache_index_def, + vlocation, + &vlocation->cache); + + if (vlocation->valid) + goto found_in_cache; +#endif + + /* try to look up an unknown volume in the cell VL databases by name */ + ret = afs_vlocation_access_vl_by_name(vlocation, name, namesz, &vldb); + if (ret < 0) { + printk("kAFS: failed to locate '%*.*s' in cell '%s'\n", + namesz, namesz, name, cell->name); + goto error; + } + + goto found_on_vlserver; + + found_in_graveyard: + /* found in the graveyard - resurrect */ + _debug("found in graveyard"); + atomic_inc(&vlocation->usage); + list_del(&vlocation->link); + list_add_tail(&vlocation->link, &cell->vl_list); + spin_unlock(&cell->vl_gylock); + + afs_kafstimod_del_timer(&vlocation->timeout); + goto active; + + found_in_memory: + /* found in memory - check to see if it's active */ + _debug("found in memory"); + atomic_inc(&vlocation->usage); + + active: + active = 1; + +#ifdef AFS_CACHING_SUPPORT + found_in_cache: +#endif + /* try to look up a cached volume in the cell VL databases by ID */ + _debug("found in cache"); + + _debug("Locally Cached: %s %02x { %08x(%x) %08x(%x) %08x(%x) }", + vlocation->vldb.name, + vlocation->vldb.vidmask, + ntohl(vlocation->vldb.servers[0].s_addr), + vlocation->vldb.srvtmask[0], + ntohl(vlocation->vldb.servers[1].s_addr), + vlocation->vldb.srvtmask[1], + ntohl(vlocation->vldb.servers[2].s_addr), + vlocation->vldb.srvtmask[2] + ); + + _debug("Vids: %08x %08x %08x", + vlocation->vldb.vid[0], + vlocation->vldb.vid[1], + vlocation->vldb.vid[2]); + + if (vlocation->vldb.vidmask & AFS_VOL_VTM_RW) { + vid = vlocation->vldb.vid[0]; + voltype = AFSVL_RWVOL; + } + else if (vlocation->vldb.vidmask & AFS_VOL_VTM_RO) { + vid = vlocation->vldb.vid[1]; + voltype = AFSVL_ROVOL; + } + else if (vlocation->vldb.vidmask & AFS_VOL_VTM_BAK) { + vid = vlocation->vldb.vid[2]; + voltype = AFSVL_BACKVOL; + } + else { + BUG(); + vid = 0; + voltype = 0; + } + + ret = afs_vlocation_access_vl_by_id(vlocation, vid, voltype, &vldb); + switch (ret) { + /* net error */ + default: + printk("kAFS: failed to volume '%*.*s' (%x) up in '%s': %d\n", + namesz, namesz, name, vid, cell->name, ret); + goto error; + + /* pulled from local cache into memory */ + case 0: + goto found_on_vlserver; + + /* uh oh... looks like the volume got deleted */ + case -ENOMEDIUM: + printk("kAFS: volume '%*.*s' (%x) does not exist '%s'\n", + namesz, namesz, name, vid, cell->name); + + /* TODO: make existing record unavailable */ + goto error; + } + + found_on_vlserver: + _debug("Done VL Lookup: %*.*s %02x { %08x(%x) %08x(%x) %08x(%x) }", + namesz, namesz, name, + vldb.vidmask, + ntohl(vldb.servers[0].s_addr), vldb.srvtmask[0], + ntohl(vldb.servers[1].s_addr), vldb.srvtmask[1], + ntohl(vldb.servers[2].s_addr), vldb.srvtmask[2] + ); + + _debug("Vids: %08x %08x %08x", vldb.vid[0], vldb.vid[1], vldb.vid[2]); + + if ((namesz < sizeof(vlocation->vldb.name) && + vlocation->vldb.name[namesz] != '\0') || + memcmp(vldb.name, name, namesz) != 0) + printk("kAFS: name of volume '%*.*s' changed to '%s' on server\n", + namesz, namesz, name, vldb.name); + + memcpy(&vlocation->vldb, &vldb, sizeof(vlocation->vldb)); + + afs_kafstimod_add_timer(&vlocation->upd_timer, 10 * HZ); + +#ifdef AFS_CACHING_SUPPORT + /* update volume entry in local cache */ + cachefs_update_cookie(vlocation->cache); +#endif + + *_vlocation = vlocation; + _leave(" = 0 (%p)",vlocation); + return 0; + + error: + if (vlocation) { + if (active) { + __afs_put_vlocation(vlocation); + } + else { + list_del(&vlocation->link); +#ifdef AFS_CACHING_SUPPORT + cachefs_relinquish_cookie(vlocation->cache, 0); +#endif + afs_put_cell(vlocation->cell); + kfree(vlocation); + } + } + + _leave(" = %d", ret); + return ret; +} /* end afs_vlocation_lookup() */ + +/*****************************************************************************/ +/* + * finish using a volume location record + * - caller must have cell->vol_sem write-locked + */ +static void __afs_put_vlocation(struct afs_vlocation *vlocation) +{ + struct afs_cell *cell; + + if (!vlocation) + return; + + _enter("%s", vlocation->vldb.name); + + cell = vlocation->cell; + + /* sanity check */ + BUG_ON(atomic_read(&vlocation->usage) <= 0); + + spin_lock(&cell->vl_gylock); + if (likely(!atomic_dec_and_test(&vlocation->usage))) { + spin_unlock(&cell->vl_gylock); + _leave(""); + return; + } + + /* move to graveyard queue */ + list_del(&vlocation->link); + list_add_tail(&vlocation->link,&cell->vl_graveyard); + + /* remove from pending timeout queue (refcounted if actually being + * updated) */ + list_del_init(&vlocation->upd_op.link); + + /* time out in 10 secs */ + afs_kafstimod_del_timer(&vlocation->upd_timer); + afs_kafstimod_add_timer(&vlocation->timeout, 10 * HZ); + + spin_unlock(&cell->vl_gylock); + + _leave(" [killed]"); +} /* end __afs_put_vlocation() */ + +/*****************************************************************************/ +/* + * finish using a volume location record + */ +void afs_put_vlocation(struct afs_vlocation *vlocation) +{ + if (vlocation) { + struct afs_cell *cell = vlocation->cell; + + down_write(&cell->vl_sem); + __afs_put_vlocation(vlocation); + up_write(&cell->vl_sem); + } +} /* end afs_put_vlocation() */ + +/*****************************************************************************/ +/* + * timeout vlocation record + * - removes from the cell's graveyard if the usage count is zero + */ +void afs_vlocation_do_timeout(struct afs_vlocation *vlocation) +{ + struct afs_cell *cell; + + _enter("%s", vlocation->vldb.name); + + cell = vlocation->cell; + + BUG_ON(atomic_read(&vlocation->usage) < 0); + + /* remove from graveyard if still dead */ + spin_lock(&cell->vl_gylock); + if (atomic_read(&vlocation->usage) == 0) + list_del_init(&vlocation->link); + else + vlocation = NULL; + spin_unlock(&cell->vl_gylock); + + if (!vlocation) { + _leave(""); + return; /* resurrected */ + } + + /* we can now destroy it properly */ +#ifdef AFS_CACHING_SUPPORT + cachefs_relinquish_cookie(vlocation->cache, 0); +#endif + afs_put_cell(cell); + + kfree(vlocation); + + _leave(" [destroyed]"); +} /* end afs_vlocation_do_timeout() */ + +/*****************************************************************************/ +/* + * send an update operation to the currently selected server + */ +static int afs_vlocation_update_begin(struct afs_vlocation *vlocation) +{ + afs_voltype_t voltype; + afs_volid_t vid; + int ret; + + _enter("%s{ufs=%u ucs=%u}", + vlocation->vldb.name, + vlocation->upd_first_svix, + vlocation->upd_curr_svix); + + /* try to look up a cached volume in the cell VL databases by ID */ + if (vlocation->vldb.vidmask & AFS_VOL_VTM_RW) { + vid = vlocation->vldb.vid[0]; + voltype = AFSVL_RWVOL; + } + else if (vlocation->vldb.vidmask & AFS_VOL_VTM_RO) { + vid = vlocation->vldb.vid[1]; + voltype = AFSVL_ROVOL; + } + else if (vlocation->vldb.vidmask & AFS_VOL_VTM_BAK) { + vid = vlocation->vldb.vid[2]; + voltype = AFSVL_BACKVOL; + } + else { + BUG(); + vid = 0; + voltype = 0; + } + + /* contact the chosen server */ + ret = afs_server_lookup( + vlocation->cell, + &vlocation->cell->vl_addrs[vlocation->upd_curr_svix], + &vlocation->upd_op.server); + + switch (ret) { + case 0: + break; + case -ENOMEM: + case -ENONET: + default: + _leave(" = %d", ret); + return ret; + } + + /* initiate the update operation */ + ret = afs_rxvl_get_entry_by_id_async(&vlocation->upd_op, vid, voltype); + if (ret < 0) { + _leave(" = %d", ret); + return ret; + } + + _leave(" = %d", ret); + return ret; +} /* end afs_vlocation_update_begin() */ + +/*****************************************************************************/ +/* + * abandon updating a VL record + * - does not restart the update timer + */ +static void afs_vlocation_update_abandon(struct afs_vlocation *vlocation, + afs_vlocation_upd_t state, + int ret) +{ + _enter("%s,%u", vlocation->vldb.name, state); + + if (ret < 0) + printk("kAFS: Abandoning VL update '%s': %d\n", + vlocation->vldb.name, ret); + + /* discard the server record */ + afs_put_server(vlocation->upd_op.server); + vlocation->upd_op.server = NULL; + + spin_lock(&afs_vlocation_update_lock); + afs_vlocation_update = NULL; + vlocation->upd_state = state; + + /* TODO: start updating next VL record on pending list */ + + spin_unlock(&afs_vlocation_update_lock); + + _leave(""); +} /* end afs_vlocation_update_abandon() */ + +/*****************************************************************************/ +/* + * handle periodic update timeouts and busy retry timeouts + * - called from kafstimod + */ +static void afs_vlocation_update_timer(struct afs_timer *timer) +{ + struct afs_vlocation *vlocation = + list_entry(timer, struct afs_vlocation, upd_timer); + int ret; + + _enter("%s", vlocation->vldb.name); + + /* only update if not in the graveyard (defend against putting too) */ + spin_lock(&vlocation->cell->vl_gylock); + + if (!atomic_read(&vlocation->usage)) + goto out_unlock1; + + spin_lock(&afs_vlocation_update_lock); + + /* if we were woken up due to EBUSY sleep then restart immediately if + * possible or else jump to front of pending queue */ + if (vlocation->upd_state == AFS_VLUPD_BUSYSLEEP) { + if (afs_vlocation_update) { + list_add(&vlocation->upd_op.link, + &afs_vlocation_update_pendq); + } + else { + afs_get_vlocation(vlocation); + afs_vlocation_update = vlocation; + vlocation->upd_state = AFS_VLUPD_INPROGRESS; + } + goto out_unlock2; + } + + /* put on pending queue if there's already another update in progress */ + if (afs_vlocation_update) { + vlocation->upd_state = AFS_VLUPD_PENDING; + list_add_tail(&vlocation->upd_op.link, + &afs_vlocation_update_pendq); + goto out_unlock2; + } + + /* hold a ref on it while actually updating */ + afs_get_vlocation(vlocation); + afs_vlocation_update = vlocation; + vlocation->upd_state = AFS_VLUPD_INPROGRESS; + + spin_unlock(&afs_vlocation_update_lock); + spin_unlock(&vlocation->cell->vl_gylock); + + /* okay... we can start the update */ + _debug("BEGIN VL UPDATE [%s]", vlocation->vldb.name); + vlocation->upd_first_svix = vlocation->cell->vl_curr_svix; + vlocation->upd_curr_svix = vlocation->upd_first_svix; + vlocation->upd_rej_cnt = 0; + vlocation->upd_busy_cnt = 0; + + ret = afs_vlocation_update_begin(vlocation); + if (ret < 0) { + afs_vlocation_update_abandon(vlocation, AFS_VLUPD_SLEEP, ret); + afs_kafstimod_add_timer(&vlocation->upd_timer, + AFS_VLDB_TIMEOUT); + afs_put_vlocation(vlocation); + } + + _leave(""); + return; + + out_unlock2: + spin_unlock(&afs_vlocation_update_lock); + out_unlock1: + spin_unlock(&vlocation->cell->vl_gylock); + _leave(""); + return; + +} /* end afs_vlocation_update_timer() */ + +/*****************************************************************************/ +/* + * attend to an update operation upon which an event happened + * - called in kafsasyncd context + */ +static void afs_vlocation_update_attend(struct afs_async_op *op) +{ + struct afs_cache_vlocation vldb; + struct afs_vlocation *vlocation = + list_entry(op, struct afs_vlocation, upd_op); + unsigned tmp; + int ret; + + _enter("%s", vlocation->vldb.name); + + ret = afs_rxvl_get_entry_by_id_async2(op, &vldb); + switch (ret) { + case -EAGAIN: + _leave(" [unfinished]"); + return; + + case 0: + _debug("END VL UPDATE: %d\n", ret); + vlocation->valid = 1; + + _debug("Done VL Lookup: %02x { %08x(%x) %08x(%x) %08x(%x) }", + vldb.vidmask, + ntohl(vldb.servers[0].s_addr), vldb.srvtmask[0], + ntohl(vldb.servers[1].s_addr), vldb.srvtmask[1], + ntohl(vldb.servers[2].s_addr), vldb.srvtmask[2] + ); + + _debug("Vids: %08x %08x %08x", + vldb.vid[0], vldb.vid[1], vldb.vid[2]); + + afs_vlocation_update_abandon(vlocation, AFS_VLUPD_SLEEP, 0); + + down_write(&vlocation->cell->vl_sem); + + /* actually update the cache */ + if (strncmp(vldb.name, vlocation->vldb.name, + sizeof(vlocation->vldb.name)) != 0) + printk("kAFS: name of volume '%s'" + " changed to '%s' on server\n", + vlocation->vldb.name, vldb.name); + + memcpy(&vlocation->vldb, &vldb, sizeof(vlocation->vldb)); + +#if 0 + /* TODO update volume entry in local cache */ +#endif + + up_write(&vlocation->cell->vl_sem); + + if (ret < 0) + printk("kAFS: failed to update local cache: %d\n", ret); + + afs_kafstimod_add_timer(&vlocation->upd_timer, + AFS_VLDB_TIMEOUT); + afs_put_vlocation(vlocation); + _leave(" [found]"); + return; + + case -ENOMEDIUM: + vlocation->upd_rej_cnt++; + goto try_next; + + /* the server is locked - retry in a very short while */ + case -EBUSY: + vlocation->upd_busy_cnt++; + if (vlocation->upd_busy_cnt > 3) + goto try_next; /* too many retries */ + + afs_vlocation_update_abandon(vlocation, + AFS_VLUPD_BUSYSLEEP, 0); + afs_kafstimod_add_timer(&vlocation->upd_timer, HZ / 2); + afs_put_vlocation(vlocation); + _leave(" [busy]"); + return; + + case -ENETUNREACH: + case -EHOSTUNREACH: + case -ECONNREFUSED: + case -EREMOTEIO: + /* record bad vlserver info in the cell too + * - TODO: use down_write_trylock() if available + */ + if (vlocation->upd_curr_svix == vlocation->cell->vl_curr_svix) + vlocation->cell->vl_curr_svix = + vlocation->cell->vl_curr_svix % + vlocation->cell->vl_naddrs; + + case -EBADRQC: + case -EINVAL: + case -EACCES: + case -EBADMSG: + goto try_next; + + default: + goto abandon; + } + + /* try contacting the next server */ + try_next: + vlocation->upd_busy_cnt = 0; + + /* discard the server record */ + afs_put_server(vlocation->upd_op.server); + vlocation->upd_op.server = NULL; + + tmp = vlocation->cell->vl_naddrs; + if (tmp == 0) + goto abandon; + + vlocation->upd_curr_svix++; + if (vlocation->upd_curr_svix >= tmp) + vlocation->upd_curr_svix = 0; + if (vlocation->upd_first_svix >= tmp) + vlocation->upd_first_svix = tmp - 1; + + /* move to the next server */ + if (vlocation->upd_curr_svix != vlocation->upd_first_svix) { + afs_vlocation_update_begin(vlocation); + _leave(" [next]"); + return; + } + + /* run out of servers to try - was the volume rejected? */ + if (vlocation->upd_rej_cnt > 0) { + printk("kAFS: Active volume no longer valid '%s'\n", + vlocation->vldb.name); + vlocation->valid = 0; + afs_vlocation_update_abandon(vlocation, AFS_VLUPD_SLEEP, 0); + afs_kafstimod_add_timer(&vlocation->upd_timer, + AFS_VLDB_TIMEOUT); + afs_put_vlocation(vlocation); + _leave(" [invalidated]"); + return; + } + + /* abandon the update */ + abandon: + afs_vlocation_update_abandon(vlocation, AFS_VLUPD_SLEEP, ret); + afs_kafstimod_add_timer(&vlocation->upd_timer, HZ * 10); + afs_put_vlocation(vlocation); + _leave(" [abandoned]"); + +} /* end afs_vlocation_update_attend() */ + +/*****************************************************************************/ +/* + * deal with an update operation being discarded + * - called in kafsasyncd context when it's dying due to rmmod + * - the call has already been aborted and put()'d + */ +static void afs_vlocation_update_discard(struct afs_async_op *op) +{ + struct afs_vlocation *vlocation = + list_entry(op, struct afs_vlocation, upd_op); + + _enter("%s", vlocation->vldb.name); + + afs_put_server(op->server); + op->server = NULL; + + afs_put_vlocation(vlocation); + + _leave(""); +} /* end afs_vlocation_update_discard() */ + +/*****************************************************************************/ +/* + * match a VLDB record stored in the cache + * - may also load target from entry + */ +#ifdef AFS_CACHING_SUPPORT +static cachefs_match_val_t afs_vlocation_cache_match(void *target, + const void *entry) +{ + const struct afs_cache_vlocation *vldb = entry; + struct afs_vlocation *vlocation = target; + + _enter("{%s},{%s}", vlocation->vldb.name, vldb->name); + + if (strncmp(vlocation->vldb.name, vldb->name, sizeof(vldb->name)) == 0 + ) { + if (!vlocation->valid || + vlocation->vldb.rtime == vldb->rtime + ) { + vlocation->vldb = *vldb; + vlocation->valid = 1; + _leave(" = SUCCESS [c->m]"); + return CACHEFS_MATCH_SUCCESS; + } + /* need to update cache if cached info differs */ + else if (memcmp(&vlocation->vldb, vldb, sizeof(*vldb)) != 0) { + /* delete if VIDs for this name differ */ + if (memcmp(&vlocation->vldb.vid, + &vldb->vid, + sizeof(vldb->vid)) != 0) { + _leave(" = DELETE"); + return CACHEFS_MATCH_SUCCESS_DELETE; + } + + _leave(" = UPDATE"); + return CACHEFS_MATCH_SUCCESS_UPDATE; + } + else { + _leave(" = SUCCESS"); + return CACHEFS_MATCH_SUCCESS; + } + } + + _leave(" = FAILED"); + return CACHEFS_MATCH_FAILED; +} /* end afs_vlocation_cache_match() */ +#endif + +/*****************************************************************************/ +/* + * update a VLDB record stored in the cache + */ +#ifdef AFS_CACHING_SUPPORT +static void afs_vlocation_cache_update(void *source, void *entry) +{ + struct afs_cache_vlocation *vldb = entry; + struct afs_vlocation *vlocation = source; + + _enter(""); + + *vldb = vlocation->vldb; + +} /* end afs_vlocation_cache_update() */ +#endif |