diff options
Diffstat (limited to 'fs/aufs/dynop.c')
-rw-r--r-- | fs/aufs/dynop.c | 369 |
1 files changed, 0 insertions, 369 deletions
diff --git a/fs/aufs/dynop.c b/fs/aufs/dynop.c deleted file mode 100644 index a04d02f91..000000000 --- a/fs/aufs/dynop.c +++ /dev/null @@ -1,369 +0,0 @@ -/* - * Copyright (C) 2010-2015 Junjiro R. Okajima - * - * This program, aufs 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. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program. If not, see <http://www.gnu.org/licenses/>. - */ - -/* - * dynamically customizable operations for regular files - */ - -#include "aufs.h" - -#define DyPrSym(key) AuDbgSym(key->dk_op.dy_hop) - -/* - * How large will these lists be? - * Usually just a few elements, 20-30 at most for each, I guess. - */ -static struct au_splhead dynop[AuDyLast]; - -static struct au_dykey *dy_gfind_get(struct au_splhead *spl, const void *h_op) -{ - struct au_dykey *key, *tmp; - struct list_head *head; - - key = NULL; - head = &spl->head; - rcu_read_lock(); - list_for_each_entry_rcu(tmp, head, dk_list) - if (tmp->dk_op.dy_hop == h_op) { - key = tmp; - kref_get(&key->dk_kref); - break; - } - rcu_read_unlock(); - - return key; -} - -static struct au_dykey *dy_bradd(struct au_branch *br, struct au_dykey *key) -{ - struct au_dykey **k, *found; - const void *h_op = key->dk_op.dy_hop; - int i; - - found = NULL; - k = br->br_dykey; - for (i = 0; i < AuBrDynOp; i++) - if (k[i]) { - if (k[i]->dk_op.dy_hop == h_op) { - found = k[i]; - break; - } - } else - break; - if (!found) { - spin_lock(&br->br_dykey_lock); - for (; i < AuBrDynOp; i++) - if (k[i]) { - if (k[i]->dk_op.dy_hop == h_op) { - found = k[i]; - break; - } - } else { - k[i] = key; - break; - } - spin_unlock(&br->br_dykey_lock); - BUG_ON(i == AuBrDynOp); /* expand the array */ - } - - return found; -} - -/* kref_get() if @key is already added */ -static struct au_dykey *dy_gadd(struct au_splhead *spl, struct au_dykey *key) -{ - struct au_dykey *tmp, *found; - struct list_head *head; - const void *h_op = key->dk_op.dy_hop; - - found = NULL; - head = &spl->head; - spin_lock(&spl->spin); - list_for_each_entry(tmp, head, dk_list) - if (tmp->dk_op.dy_hop == h_op) { - kref_get(&tmp->dk_kref); - found = tmp; - break; - } - if (!found) - list_add_rcu(&key->dk_list, head); - spin_unlock(&spl->spin); - - if (!found) - DyPrSym(key); - return found; -} - -static void dy_free_rcu(struct rcu_head *rcu) -{ - struct au_dykey *key; - - key = container_of(rcu, struct au_dykey, dk_rcu); - DyPrSym(key); - kfree(key); -} - -static void dy_free(struct kref *kref) -{ - struct au_dykey *key; - struct au_splhead *spl; - - key = container_of(kref, struct au_dykey, dk_kref); - spl = dynop + key->dk_op.dy_type; - au_spl_del_rcu(&key->dk_list, spl); - call_rcu(&key->dk_rcu, dy_free_rcu); -} - -void au_dy_put(struct au_dykey *key) -{ - kref_put(&key->dk_kref, dy_free); -} - -/* ---------------------------------------------------------------------- */ - -#define DyDbgSize(cnt, op) AuDebugOn(cnt != sizeof(op)/sizeof(void *)) - -#ifdef CONFIG_AUFS_DEBUG -#define DyDbgDeclare(cnt) unsigned int cnt = 0 -#define DyDbgInc(cnt) do { cnt++; } while (0) -#else -#define DyDbgDeclare(cnt) do {} while (0) -#define DyDbgInc(cnt) do {} while (0) -#endif - -#define DySet(func, dst, src, h_op, h_sb) do { \ - DyDbgInc(cnt); \ - if (h_op->func) { \ - if (src.func) \ - dst.func = src.func; \ - else \ - AuDbg("%s %s\n", au_sbtype(h_sb), #func); \ - } \ -} while (0) - -#define DySetForce(func, dst, src) do { \ - AuDebugOn(!src.func); \ - DyDbgInc(cnt); \ - dst.func = src.func; \ -} while (0) - -#define DySetAop(func) \ - DySet(func, dyaop->da_op, aufs_aop, h_aop, h_sb) -#define DySetAopForce(func) \ - DySetForce(func, dyaop->da_op, aufs_aop) - -static void dy_aop(struct au_dykey *key, const void *h_op, - struct super_block *h_sb __maybe_unused) -{ - struct au_dyaop *dyaop = (void *)key; - const struct address_space_operations *h_aop = h_op; - DyDbgDeclare(cnt); - - AuDbg("%s\n", au_sbtype(h_sb)); - - DySetAop(writepage); - DySetAopForce(readpage); /* force */ - DySetAop(writepages); - DySetAop(set_page_dirty); - DySetAop(readpages); - DySetAop(write_begin); - DySetAop(write_end); - DySetAop(bmap); - DySetAop(invalidatepage); - DySetAop(releasepage); - DySetAop(freepage); - /* this one will be changed according to an aufs mount option */ - DySetAop(direct_IO); - DySetAop(migratepage); - DySetAop(launder_page); - DySetAop(is_partially_uptodate); - DySetAop(is_dirty_writeback); - DySetAop(error_remove_page); - DySetAop(swap_activate); - DySetAop(swap_deactivate); - - DyDbgSize(cnt, *h_aop); -} - -/* ---------------------------------------------------------------------- */ - -static void dy_bug(struct kref *kref) -{ - BUG(); -} - -static struct au_dykey *dy_get(struct au_dynop *op, struct au_branch *br) -{ - struct au_dykey *key, *old; - struct au_splhead *spl; - struct op { - unsigned int sz; - void (*set)(struct au_dykey *key, const void *h_op, - struct super_block *h_sb __maybe_unused); - }; - static const struct op a[] = { - [AuDy_AOP] = { - .sz = sizeof(struct au_dyaop), - .set = dy_aop - } - }; - const struct op *p; - - spl = dynop + op->dy_type; - key = dy_gfind_get(spl, op->dy_hop); - if (key) - goto out_add; /* success */ - - p = a + op->dy_type; - key = kzalloc(p->sz, GFP_NOFS); - if (unlikely(!key)) { - key = ERR_PTR(-ENOMEM); - goto out; - } - - key->dk_op.dy_hop = op->dy_hop; - kref_init(&key->dk_kref); - p->set(key, op->dy_hop, au_br_sb(br)); - old = dy_gadd(spl, key); - if (old) { - kfree(key); - key = old; - } - -out_add: - old = dy_bradd(br, key); - if (old) - /* its ref-count should never be zero here */ - kref_put(&key->dk_kref, dy_bug); -out: - return key; -} - -/* ---------------------------------------------------------------------- */ -/* - * Aufs prohibits O_DIRECT by defaut even if the branch supports it. - * This behaviour is necessary to return an error from open(O_DIRECT) instead - * of the succeeding I/O. The dio mount option enables O_DIRECT and makes - * open(O_DIRECT) always succeed, but the succeeding I/O may return an error. - * See the aufs manual in detail. - */ -static void dy_adx(struct au_dyaop *dyaop, int do_dx) -{ - if (!do_dx) - dyaop->da_op.direct_IO = NULL; - else - dyaop->da_op.direct_IO = aufs_aop.direct_IO; -} - -static struct au_dyaop *dy_aget(struct au_branch *br, - const struct address_space_operations *h_aop, - int do_dx) -{ - struct au_dyaop *dyaop; - struct au_dynop op; - - op.dy_type = AuDy_AOP; - op.dy_haop = h_aop; - dyaop = (void *)dy_get(&op, br); - if (IS_ERR(dyaop)) - goto out; - dy_adx(dyaop, do_dx); - -out: - return dyaop; -} - -int au_dy_iaop(struct inode *inode, aufs_bindex_t bindex, - struct inode *h_inode) -{ - int err, do_dx; - struct super_block *sb; - struct au_branch *br; - struct au_dyaop *dyaop; - - AuDebugOn(!S_ISREG(h_inode->i_mode)); - IiMustWriteLock(inode); - - sb = inode->i_sb; - br = au_sbr(sb, bindex); - do_dx = !!au_opt_test(au_mntflags(sb), DIO); - dyaop = dy_aget(br, h_inode->i_mapping->a_ops, do_dx); - err = PTR_ERR(dyaop); - if (IS_ERR(dyaop)) - /* unnecessary to call dy_fput() */ - goto out; - - err = 0; - inode->i_mapping->a_ops = &dyaop->da_op; - -out: - return err; -} - -/* - * Is it safe to replace a_ops during the inode/file is in operation? - * Yes, I hope so. - */ -int au_dy_irefresh(struct inode *inode) -{ - int err; - aufs_bindex_t bstart; - struct inode *h_inode; - - err = 0; - if (S_ISREG(inode->i_mode)) { - bstart = au_ibstart(inode); - h_inode = au_h_iptr(inode, bstart); - err = au_dy_iaop(inode, bstart, h_inode); - } - return err; -} - -void au_dy_arefresh(int do_dx) -{ - struct au_splhead *spl; - struct list_head *head; - struct au_dykey *key; - - spl = dynop + AuDy_AOP; - head = &spl->head; - spin_lock(&spl->spin); - list_for_each_entry(key, head, dk_list) - dy_adx((void *)key, do_dx); - spin_unlock(&spl->spin); -} - -/* ---------------------------------------------------------------------- */ - -void __init au_dy_init(void) -{ - int i; - - /* make sure that 'struct au_dykey *' can be any type */ - BUILD_BUG_ON(offsetof(struct au_dyaop, da_key)); - - for (i = 0; i < AuDyLast; i++) - au_spl_init(dynop + i); -} - -void au_dy_fin(void) -{ - int i; - - for (i = 0; i < AuDyLast; i++) - WARN_ON(!list_empty(&dynop[i].head)); -} |