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-rw-r--r--fs/aufs/sbinfo.c356
1 files changed, 356 insertions, 0 deletions
diff --git a/fs/aufs/sbinfo.c b/fs/aufs/sbinfo.c
new file mode 100644
index 000000000..4e59efc08
--- /dev/null
+++ b/fs/aufs/sbinfo.c
@@ -0,0 +1,356 @@
+/*
+ * Copyright (C) 2005-2015 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/>.
+ */
+
+/*
+ * superblock private data
+ */
+
+#include "aufs.h"
+
+/*
+ * they are necessary regardless sysfs is disabled.
+ */
+void au_si_free(struct kobject *kobj)
+{
+ int i;
+ struct au_sbinfo *sbinfo;
+ char *locked __maybe_unused; /* debug only */
+
+ sbinfo = container_of(kobj, struct au_sbinfo, si_kobj);
+ for (i = 0; i < AuPlink_NHASH; i++)
+ AuDebugOn(!hlist_empty(&sbinfo->si_plink[i].head));
+ AuDebugOn(atomic_read(&sbinfo->si_nowait.nw_len));
+
+ au_rw_write_lock(&sbinfo->si_rwsem);
+ au_br_free(sbinfo);
+ au_rw_write_unlock(&sbinfo->si_rwsem);
+
+ AuDebugOn(radix_tree_gang_lookup
+ (&sbinfo->au_si_pid.tree, (void **)&locked,
+ /*first_index*/PID_MAX_DEFAULT - 1,
+ /*max_items*/sizeof(locked)/sizeof(*locked)));
+
+ kfree(sbinfo->si_branch);
+ kfree(sbinfo->au_si_pid.bitmap);
+ mutex_destroy(&sbinfo->si_xib_mtx);
+ AuRwDestroy(&sbinfo->si_rwsem);
+
+ kfree(sbinfo);
+}
+
+int au_si_alloc(struct super_block *sb)
+{
+ int err, i;
+ struct au_sbinfo *sbinfo;
+ static struct lock_class_key aufs_si;
+
+ err = -ENOMEM;
+ sbinfo = kzalloc(sizeof(*sbinfo), GFP_NOFS);
+ if (unlikely(!sbinfo))
+ goto out;
+
+ BUILD_BUG_ON(sizeof(unsigned long) !=
+ sizeof(*sbinfo->au_si_pid.bitmap));
+ sbinfo->au_si_pid.bitmap = kcalloc(BITS_TO_LONGS(PID_MAX_DEFAULT),
+ sizeof(*sbinfo->au_si_pid.bitmap),
+ GFP_NOFS);
+ if (unlikely(!sbinfo->au_si_pid.bitmap))
+ goto out_sbinfo;
+
+ /* will be reallocated separately */
+ sbinfo->si_branch = kzalloc(sizeof(*sbinfo->si_branch), GFP_NOFS);
+ if (unlikely(!sbinfo->si_branch))
+ goto out_pidmap;
+
+ err = sysaufs_si_init(sbinfo);
+ if (unlikely(err))
+ goto out_br;
+
+ au_nwt_init(&sbinfo->si_nowait);
+ au_rw_init_wlock(&sbinfo->si_rwsem);
+ au_rw_class(&sbinfo->si_rwsem, &aufs_si);
+ spin_lock_init(&sbinfo->au_si_pid.tree_lock);
+ INIT_RADIX_TREE(&sbinfo->au_si_pid.tree, GFP_ATOMIC | __GFP_NOFAIL);
+
+ atomic_long_set(&sbinfo->si_ninodes, 0);
+ atomic_long_set(&sbinfo->si_nfiles, 0);
+
+ sbinfo->si_bend = -1;
+ sbinfo->si_last_br_id = AUFS_BRANCH_MAX / 2;
+
+ sbinfo->si_wbr_copyup = AuWbrCopyup_Def;
+ sbinfo->si_wbr_create = AuWbrCreate_Def;
+ sbinfo->si_wbr_copyup_ops = au_wbr_copyup_ops + sbinfo->si_wbr_copyup;
+ sbinfo->si_wbr_create_ops = au_wbr_create_ops + sbinfo->si_wbr_create;
+
+ au_fhsm_init(sbinfo);
+
+ sbinfo->si_mntflags = au_opts_plink(AuOpt_Def);
+
+ sbinfo->si_xino_jiffy = jiffies;
+ sbinfo->si_xino_expire
+ = msecs_to_jiffies(AUFS_XINO_DEF_SEC * MSEC_PER_SEC);
+ mutex_init(&sbinfo->si_xib_mtx);
+ sbinfo->si_xino_brid = -1;
+ /* leave si_xib_last_pindex and si_xib_next_bit */
+
+ au_sphl_init(&sbinfo->si_aopen);
+
+ sbinfo->si_rdcache = msecs_to_jiffies(AUFS_RDCACHE_DEF * MSEC_PER_SEC);
+ sbinfo->si_rdblk = AUFS_RDBLK_DEF;
+ sbinfo->si_rdhash = AUFS_RDHASH_DEF;
+ sbinfo->si_dirwh = AUFS_DIRWH_DEF;
+
+ for (i = 0; i < AuPlink_NHASH; i++)
+ au_sphl_init(sbinfo->si_plink + i);
+ init_waitqueue_head(&sbinfo->si_plink_wq);
+ spin_lock_init(&sbinfo->si_plink_maint_lock);
+
+ au_sphl_init(&sbinfo->si_files);
+
+ /* leave other members for sysaufs and si_mnt. */
+ sbinfo->si_sb = sb;
+ sb->s_fs_info = sbinfo;
+ si_pid_set(sb);
+ return 0; /* success */
+
+out_br:
+ kfree(sbinfo->si_branch);
+out_pidmap:
+ kfree(sbinfo->au_si_pid.bitmap);
+out_sbinfo:
+ kfree(sbinfo);
+out:
+ return err;
+}
+
+int au_sbr_realloc(struct au_sbinfo *sbinfo, int nbr)
+{
+ int err, sz;
+ struct au_branch **brp;
+
+ AuRwMustWriteLock(&sbinfo->si_rwsem);
+
+ err = -ENOMEM;
+ sz = sizeof(*brp) * (sbinfo->si_bend + 1);
+ if (unlikely(!sz))
+ sz = sizeof(*brp);
+ brp = au_kzrealloc(sbinfo->si_branch, sz, sizeof(*brp) * nbr, GFP_NOFS);
+ if (brp) {
+ sbinfo->si_branch = brp;
+ err = 0;
+ }
+
+ return err;
+}
+
+/* ---------------------------------------------------------------------- */
+
+unsigned int au_sigen_inc(struct super_block *sb)
+{
+ unsigned int gen;
+ struct inode *inode;
+
+ SiMustWriteLock(sb);
+
+ gen = ++au_sbi(sb)->si_generation;
+ au_update_digen(sb->s_root);
+ inode = d_inode(sb->s_root);
+ au_update_iigen(inode, /*half*/0);
+ inode->i_version++;
+ return gen;
+}
+
+aufs_bindex_t au_new_br_id(struct super_block *sb)
+{
+ aufs_bindex_t br_id;
+ int i;
+ struct au_sbinfo *sbinfo;
+
+ SiMustWriteLock(sb);
+
+ sbinfo = au_sbi(sb);
+ for (i = 0; i <= AUFS_BRANCH_MAX; i++) {
+ br_id = ++sbinfo->si_last_br_id;
+ AuDebugOn(br_id < 0);
+ if (br_id && au_br_index(sb, br_id) < 0)
+ return br_id;
+ }
+
+ return -1;
+}
+
+/* ---------------------------------------------------------------------- */
+
+/* it is ok that new 'nwt' tasks are appended while we are sleeping */
+int si_read_lock(struct super_block *sb, int flags)
+{
+ int err;
+
+ err = 0;
+ if (au_ftest_lock(flags, FLUSH))
+ au_nwt_flush(&au_sbi(sb)->si_nowait);
+
+ si_noflush_read_lock(sb);
+ err = au_plink_maint(sb, flags);
+ if (unlikely(err))
+ si_read_unlock(sb);
+
+ return err;
+}
+
+int si_write_lock(struct super_block *sb, int flags)
+{
+ int err;
+
+ if (au_ftest_lock(flags, FLUSH))
+ au_nwt_flush(&au_sbi(sb)->si_nowait);
+
+ si_noflush_write_lock(sb);
+ err = au_plink_maint(sb, flags);
+ if (unlikely(err))
+ si_write_unlock(sb);
+
+ return err;
+}
+
+/* dentry and super_block lock. call at entry point */
+int aufs_read_lock(struct dentry *dentry, int flags)
+{
+ int err;
+ struct super_block *sb;
+
+ sb = dentry->d_sb;
+ err = si_read_lock(sb, flags);
+ if (unlikely(err))
+ goto out;
+
+ if (au_ftest_lock(flags, DW))
+ di_write_lock_child(dentry);
+ else
+ di_read_lock_child(dentry, flags);
+
+ if (au_ftest_lock(flags, GEN)) {
+ err = au_digen_test(dentry, au_sigen(sb));
+ AuDebugOn(!err && au_dbrange_test(dentry));
+ if (unlikely(err))
+ aufs_read_unlock(dentry, flags);
+ }
+
+out:
+ return err;
+}
+
+void aufs_read_unlock(struct dentry *dentry, int flags)
+{
+ if (au_ftest_lock(flags, DW))
+ di_write_unlock(dentry);
+ else
+ di_read_unlock(dentry, flags);
+ si_read_unlock(dentry->d_sb);
+}
+
+void aufs_write_lock(struct dentry *dentry)
+{
+ si_write_lock(dentry->d_sb, AuLock_FLUSH | AuLock_NOPLMW);
+ di_write_lock_child(dentry);
+}
+
+void aufs_write_unlock(struct dentry *dentry)
+{
+ di_write_unlock(dentry);
+ si_write_unlock(dentry->d_sb);
+}
+
+int aufs_read_and_write_lock2(struct dentry *d1, struct dentry *d2, int flags)
+{
+ int err;
+ unsigned int sigen;
+ struct super_block *sb;
+
+ sb = d1->d_sb;
+ err = si_read_lock(sb, flags);
+ if (unlikely(err))
+ goto out;
+
+ di_write_lock2_child(d1, d2, au_ftest_lock(flags, DIR));
+
+ if (au_ftest_lock(flags, GEN)) {
+ sigen = au_sigen(sb);
+ err = au_digen_test(d1, sigen);
+ AuDebugOn(!err && au_dbrange_test(d1));
+ if (!err) {
+ err = au_digen_test(d2, sigen);
+ AuDebugOn(!err && au_dbrange_test(d2));
+ }
+ if (unlikely(err))
+ aufs_read_and_write_unlock2(d1, d2);
+ }
+
+out:
+ return err;
+}
+
+void aufs_read_and_write_unlock2(struct dentry *d1, struct dentry *d2)
+{
+ di_write_unlock2(d1, d2);
+ si_read_unlock(d1->d_sb);
+}
+
+/* ---------------------------------------------------------------------- */
+
+int si_pid_test_slow(struct super_block *sb)
+{
+ void *p;
+
+ rcu_read_lock();
+ p = radix_tree_lookup(&au_sbi(sb)->au_si_pid.tree, current->pid);
+ rcu_read_unlock();
+
+ return (long)!!p;
+}
+
+void si_pid_set_slow(struct super_block *sb)
+{
+ int err;
+ struct au_sbinfo *sbinfo;
+
+ AuDebugOn(si_pid_test_slow(sb));
+
+ sbinfo = au_sbi(sb);
+ err = radix_tree_preload(GFP_NOFS | __GFP_NOFAIL);
+ AuDebugOn(err);
+ spin_lock(&sbinfo->au_si_pid.tree_lock);
+ err = radix_tree_insert(&sbinfo->au_si_pid.tree, current->pid,
+ /*any valid ptr*/sb);
+ spin_unlock(&sbinfo->au_si_pid.tree_lock);
+ AuDebugOn(err);
+ radix_tree_preload_end();
+}
+
+void si_pid_clr_slow(struct super_block *sb)
+{
+ void *p;
+ struct au_sbinfo *sbinfo;
+
+ AuDebugOn(!si_pid_test_slow(sb));
+
+ sbinfo = au_sbi(sb);
+ spin_lock(&sbinfo->au_si_pid.tree_lock);
+ p = radix_tree_delete(&sbinfo->au_si_pid.tree, current->pid);
+ spin_unlock(&sbinfo->au_si_pid.tree_lock);
+}