diff options
| -rw-r--r-- | fs/afs/Makefile | 1 | ||||
| -rw-r--r-- | fs/afs/rotate.c | 254 | ||||
| -rw-r--r-- | fs/afs/volume.c | 250 |
3 files changed, 255 insertions, 250 deletions
diff --git a/fs/afs/Makefile b/fs/afs/Makefile index 8493839..192d476 100644 --- a/fs/afs/Makefile +++ b/fs/afs/Makefile @@ -20,6 +20,7 @@ kafs-objs := \ misc.o \ mntpt.o \ proc.o \ + rotate.o \ rxrpc.o \ security.o \ server.o \ diff --git a/fs/afs/rotate.c b/fs/afs/rotate.c new file mode 100644 index 0000000..c7975b3 --- /dev/null +++ b/fs/afs/rotate.c @@ -0,0 +1,254 @@ +/* Handle fileserver selection and rotation. + * + * Copyright (C) 2017 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 Licence + * as published by the Free Software Foundation; either version + * 2 of the Licence, or (at your option) any later version. + */ + +#include <linux/kernel.h> +#include <linux/slab.h> +#include "internal.h" + +/* + * Initialise a filesystem server cursor for iterating over FS servers. + */ +void afs_init_fs_cursor(struct afs_fs_cursor *fc, struct afs_vnode *vnode) +{ + memset(fc, 0, sizeof(*fc)); +} + +/* + * Set a filesystem server cursor for using a specific FS server. + */ +int afs_set_fs_cursor(struct afs_fs_cursor *fc, struct afs_vnode *vnode) +{ + afs_init_fs_cursor(fc, vnode); + + read_seqlock_excl(&vnode->cb_lock); + if (vnode->cb_interest) { + if (vnode->cb_interest->server->fs_state == 0) + fc->server = afs_get_server(vnode->cb_interest->server); + else + fc->ac.error = vnode->cb_interest->server->fs_state; + } else { + fc->ac.error = -ESTALE; + } + read_sequnlock_excl(&vnode->cb_lock); + + return fc->ac.error; +} + +/* + * pick a server to use to try accessing this volume + * - returns with an elevated usage count on the server chosen + */ +bool afs_volume_pick_fileserver(struct afs_fs_cursor *fc, struct afs_vnode *vnode) +{ + struct afs_volume *volume = vnode->volume; + struct afs_server *server; + int ret, state, loop; + + _enter("%s", volume->vlocation->vldb.name); + + /* stick with the server we're already using if we can */ + if (vnode->cb_interest && vnode->cb_interest->server->fs_state == 0) { + fc->server = afs_get_server(vnode->cb_interest->server); + goto set_server; + } + + down_read(&volume->server_sem); + + /* handle the no-server case */ + if (volume->nservers == 0) { + fc->ac.error = volume->rjservers ? -ENOMEDIUM : -ESTALE; + up_read(&volume->server_sem); + _leave(" = f [no servers %d]", fc->ac.error); + return false; + } + + /* basically, just search the list for the first live server and use + * that */ + ret = 0; + for (loop = 0; loop < volume->nservers; loop++) { + server = volume->servers[loop]; + state = server->fs_state; + + _debug("consider %d [%d]", loop, state); + + switch (state) { + case 0: + goto picked_server; + + case -ENETUNREACH: + if (ret == 0) + ret = state; + break; + + case -EHOSTUNREACH: + if (ret == 0 || + ret == -ENETUNREACH) + ret = state; + break; + + case -ECONNREFUSED: + if (ret == 0 || + ret == -ENETUNREACH || + ret == -EHOSTUNREACH) + ret = state; + break; + + default: + case -EREMOTEIO: + if (ret == 0 || + ret == -ENETUNREACH || + ret == -EHOSTUNREACH || + ret == -ECONNREFUSED) + ret = state; + break; + } + } + +error: + fc->ac.error = ret; + + /* no available servers + * - TODO: handle the no active servers case better + */ + up_read(&volume->server_sem); + _leave(" = f [%d]", fc->ac.error); + return false; + +picked_server: + /* Found an apparently healthy server. We need to register an interest + * in receiving callbacks before we talk to it. + */ + ret = afs_register_server_cb_interest(vnode, + &volume->cb_interests[loop], server); + if (ret < 0) + goto error; + + fc->server = afs_get_server(server); + up_read(&volume->server_sem); +set_server: + fc->ac.alist = afs_get_addrlist(fc->server->addrs); + fc->ac.addr = &fc->ac.alist->addrs[0]; + _debug("USING SERVER: %pIS\n", &fc->ac.addr->transport); + _leave(" = t (picked %pIS)", &fc->ac.addr->transport); + return true; +} + +/* + * release a server after use + * - releases the ref on the server struct that was acquired by picking + * - records result of using a particular server to access a volume + * - return true to try again, false if okay or to issue error + * - the caller must release the server struct if result was false + */ +bool afs_iterate_fs_cursor(struct afs_fs_cursor *fc, + struct afs_vnode *vnode) +{ + struct afs_volume *volume = vnode->volume; + struct afs_server *server = fc->server; + unsigned loop; + + _enter("%s,%pIS,%d", + volume->vlocation->vldb.name, &fc->ac.addr->transport, + fc->ac.error); + + switch (fc->ac.error) { + /* success */ + case 0: + server->fs_state = 0; + _leave(" = f"); + return false; + + /* the fileserver denied all knowledge of the volume */ + case -ENOMEDIUM: + down_write(&volume->server_sem); + + /* firstly, find where the server is in the active list (if it + * is) */ + for (loop = 0; loop < volume->nservers; loop++) + if (volume->servers[loop] == server) + goto present; + + /* no longer there - may have been discarded by another op */ + goto try_next_server_upw; + + present: + volume->nservers--; + memmove(&volume->servers[loop], + &volume->servers[loop + 1], + sizeof(volume->servers[loop]) * + (volume->nservers - loop)); + volume->servers[volume->nservers] = NULL; + afs_put_server(afs_v2net(vnode), server); + volume->rjservers++; + + if (volume->nservers > 0) + /* another server might acknowledge its existence */ + goto try_next_server_upw; + + /* handle the case where all the fileservers have rejected the + * volume + * - TODO: try asking the fileservers for volume information + * - TODO: contact the VL server again to see if the volume is + * no longer registered + */ + up_write(&volume->server_sem); + afs_put_server(afs_v2net(vnode), server); + fc->server = NULL; + _leave(" = f [completely rejected]"); + return false; + + /* problem reaching the server */ + case -ENETUNREACH: + case -EHOSTUNREACH: + case -ECONNREFUSED: + case -ETIME: + case -ETIMEDOUT: + case -EREMOTEIO: + /* mark the server as dead + * TODO: vary dead timeout depending on error + */ + spin_lock(&server->fs_lock); + if (!server->fs_state) { + server->fs_state = fc->ac.error; + printk("kAFS: SERVER DEAD state=%d\n", fc->ac.error); + } + spin_unlock(&server->fs_lock); + goto try_next_server; + + /* miscellaneous error */ + default: + case -ENOMEM: + case -ENONET: + /* tell the caller to accept the result */ + afs_put_server(afs_v2net(vnode), server); + fc->server = NULL; + _leave(" = f [local failure]"); + return false; + } + + /* tell the caller to loop around and try the next server */ +try_next_server_upw: + up_write(&volume->server_sem); +try_next_server: + afs_put_server(afs_v2net(vnode), server); + _leave(" = t [try next server]"); + return true; +} + +/* + * Clean up a fileserver cursor. + */ +int afs_end_fs_cursor(struct afs_fs_cursor *fc, struct afs_net *net) +{ + afs_end_cursor(&fc->ac); + afs_put_server(net, fc->server); + return fc->ac.error; +} diff --git a/fs/afs/volume.c b/fs/afs/volume.c index d282cd0..3c5ad1c 100644 --- a/fs/afs/volume.c +++ b/fs/afs/volume.c @@ -10,12 +10,7 @@ */ #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 <linux/sched.h> #include "internal.h" static const char *afs_voltypes[] = { "R/W", "R/O", "BAK" }; @@ -208,248 +203,3 @@ void afs_put_volume(struct afs_cell *cell, struct afs_volume *volume) _leave(" [destroyed]"); } - -/* - * Initialise a filesystem server cursor for iterating over FS servers. - */ -void afs_init_fs_cursor(struct afs_fs_cursor *fc, struct afs_vnode *vnode) -{ - fc->ac.alist = NULL; - fc->ac.addr = NULL; - fc->ac.start = 0; - fc->ac.index = 0; - fc->ac.error = 0; - fc->server = NULL; -} - -/* - * Set a filesystem server cursor for using a specific FS server. - */ -int afs_set_fs_cursor(struct afs_fs_cursor *fc, struct afs_vnode *vnode) -{ - afs_init_fs_cursor(fc, vnode); - - read_seqlock_excl(&vnode->cb_lock); - if (vnode->cb_interest) { - if (vnode->cb_interest->server->fs_state == 0) - fc->server = afs_get_server(vnode->cb_interest->server); - else - fc->ac.error = vnode->cb_interest->server->fs_state; - } else { - fc->ac.error = -ESTALE; - } - read_sequnlock_excl(&vnode->cb_lock); - - return fc->ac.error; -} - -/* - * pick a server to use to try accessing this volume - * - returns with an elevated usage count on the server chosen - */ -bool afs_volume_pick_fileserver(struct afs_fs_cursor *fc, struct afs_vnode *vnode) -{ - struct afs_volume *volume = vnode->volume; - struct afs_server *server; - int ret, state, loop; - - _enter("%s", volume->vlocation->vldb.name); - - /* stick with the server we're already using if we can */ - if (vnode->cb_interest && vnode->cb_interest->server->fs_state == 0) { - fc->server = afs_get_server(vnode->cb_interest->server); - goto set_server; - } - - down_read(&volume->server_sem); - - /* handle the no-server case */ - if (volume->nservers == 0) { - fc->ac.error = volume->rjservers ? -ENOMEDIUM : -ESTALE; - up_read(&volume->server_sem); - _leave(" = f [no servers %d]", fc->ac.error); - return false; - } - - /* basically, just search the list for the first live server and use - * that */ - ret = 0; - for (loop = 0; loop < volume->nservers; loop++) { - server = volume->servers[loop]; - state = server->fs_state; - - _debug("consider %d [%d]", loop, state); - - switch (state) { - case 0: - goto picked_server; - - case -ENETUNREACH: - if (ret == 0) - ret = state; - break; - - case -EHOSTUNREACH: - if (ret == 0 || - ret == -ENETUNREACH) - ret = state; - break; - - case -ECONNREFUSED: - if (ret == 0 || - ret == -ENETUNREACH || - ret == -EHOSTUNREACH) - ret = state; - break; - - default: - case -EREMOTEIO: - if (ret == 0 || - ret == -ENETUNREACH || - ret == -EHOSTUNREACH || - ret == -ECONNREFUSED) - ret = state; - break; - } - } - -error: - fc->ac.error = ret; - - /* no available servers - * - TODO: handle the no active servers case better - */ - up_read(&volume->server_sem); - _leave(" = f [%d]", fc->ac.error); - return false; - -picked_server: - /* Found an apparently healthy server. We need to register an interest - * in receiving callbacks before we talk to it. - */ - ret = afs_register_server_cb_interest(vnode, - &volume->cb_interests[loop], server); - if (ret < 0) - goto error; - - fc->server = afs_get_server(server); - up_read(&volume->server_sem); -set_server: - fc->ac.alist = afs_get_addrlist(fc->server->addrs); - fc->ac.addr = &fc->ac.alist->addrs[0]; - _debug("USING SERVER: %pIS\n", &fc->ac.addr->transport); - _leave(" = t (picked %pIS)", &fc->ac.addr->transport); - return true; -} - -/* - * release a server after use - * - releases the ref on the server struct that was acquired by picking - * - records result of using a particular server to access a volume - * - return true to try again, false if okay or to issue error - * - the caller must release the server struct if result was false - */ -bool afs_iterate_fs_cursor(struct afs_fs_cursor *fc, - struct afs_vnode *vnode) -{ - struct afs_volume *volume = vnode->volume; - struct afs_server *server = fc->server; - unsigned loop; - - _enter("%s,%pIS,%d", - volume->vlocation->vldb.name, &fc->ac.addr->transport, - fc->ac.error); - - switch (fc->ac.error) { - /* success */ - case 0: - server->fs_state = 0; - _leave(" = f"); - return false; - - /* the fileserver denied all knowledge of the volume */ - case -ENOMEDIUM: - down_write(&volume->server_sem); - - /* firstly, find where the server is in the active list (if it - * is) */ - for (loop = 0; loop < volume->nservers; loop++) - if (volume->servers[loop] == server) - goto present; - - /* no longer there - may have been discarded by another op */ - goto try_next_server_upw; - - present: - volume->nservers--; - memmove(&volume->servers[loop], - &volume->servers[loop + 1], - sizeof(volume->servers[loop]) * - (volume->nservers - loop)); - volume->servers[volume->nservers] = NULL; - afs_put_server(afs_v2net(vnode), server); - volume->rjservers++; - - if (volume->nservers > 0) - /* another server might acknowledge its existence */ - goto try_next_server_upw; - - /* handle the case where all the fileservers have rejected the - * volume - * - TODO: try asking the fileservers for volume information - * - TODO: contact the VL server again to see if the volume is - * no longer registered - */ - up_write(&volume->server_sem); - afs_put_server(afs_v2net(vnode), server); - fc->server = NULL; - _leave(" = f [completely rejected]"); - return false; - - /* problem reaching the server */ - case -ENETUNREACH: - case -EHOSTUNREACH: - case -ECONNREFUSED: - case -ETIME: - case -ETIMEDOUT: - case -EREMOTEIO: - /* mark the server as dead - * TODO: vary dead timeout depending on error - */ - spin_lock(&server->fs_lock); - if (!server->fs_state) { - server->fs_state = fc->ac.error; - printk("kAFS: SERVER DEAD state=%d\n", fc->ac.error); - } - spin_unlock(&server->fs_lock); - goto try_next_server; - - /* miscellaneous error */ - default: - case -ENOMEM: - case -ENONET: - /* tell the caller to accept the result */ - afs_put_server(afs_v2net(vnode), server); - fc->server = NULL; - _leave(" = f [local failure]"); - return false; - } - - /* tell the caller to loop around and try the next server */ -try_next_server_upw: - up_write(&volume->server_sem); -try_next_server: - afs_put_server(afs_v2net(vnode), server); - _leave(" = t [try next server]"); - return true; -} - -/* - * Clean up a fileserver cursor. - */ -int afs_end_fs_cursor(struct afs_fs_cursor *fc, struct afs_net *net) -{ - afs_end_cursor(&fc->ac); - afs_put_server(net, fc->server); - return fc->ac.error; -} |
