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-rw-r--r--fs/aufs/super.h589
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diff --git a/fs/aufs/super.h b/fs/aufs/super.h
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+++ b/fs/aufs/super.h
@@ -0,0 +1,589 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2005-2020 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/>.
+ */
+
+/*
+ * super_block operations
+ */
+
+#ifndef __AUFS_SUPER_H__
+#define __AUFS_SUPER_H__
+
+#ifdef __KERNEL__
+
+#include <linux/fs.h>
+#include <linux/kobject.h>
+#include "hbl.h"
+#include "lcnt.h"
+#include "rwsem.h"
+#include "wkq.h"
+
+/* policies to select one among multiple writable branches */
+struct au_wbr_copyup_operations {
+ int (*copyup)(struct dentry *dentry);
+};
+
+#define AuWbr_DIR 1 /* target is a dir */
+#define AuWbr_PARENT (1 << 1) /* always require a parent */
+
+#define au_ftest_wbr(flags, name) ((flags) & AuWbr_##name)
+#define au_fset_wbr(flags, name) { (flags) |= AuWbr_##name; }
+#define au_fclr_wbr(flags, name) { (flags) &= ~AuWbr_##name; }
+
+struct au_wbr_create_operations {
+ int (*create)(struct dentry *dentry, unsigned int flags);
+ int (*init)(struct super_block *sb);
+ int (*fin)(struct super_block *sb);
+};
+
+struct au_wbr_mfs {
+ struct mutex mfs_lock; /* protect this structure */
+ unsigned long mfs_jiffy;
+ unsigned long mfs_expire;
+ aufs_bindex_t mfs_bindex;
+
+ unsigned long long mfsrr_bytes;
+ unsigned long long mfsrr_watermark;
+};
+
+#define AuPlink_NHASH 100
+static inline int au_plink_hash(ino_t ino)
+{
+ return ino % AuPlink_NHASH;
+}
+
+/* File-based Hierarchical Storage Management */
+struct au_fhsm {
+#ifdef CONFIG_AUFS_FHSM
+ /* allow only one process who can receive the notification */
+ spinlock_t fhsm_spin;
+ pid_t fhsm_pid;
+ wait_queue_head_t fhsm_wqh;
+ atomic_t fhsm_readable;
+
+ /* these are protected by si_rwsem */
+ unsigned long fhsm_expire;
+ aufs_bindex_t fhsm_bottom;
+#endif
+};
+
+struct au_branch;
+struct au_sbinfo {
+ /* nowait tasks in the system-wide workqueue */
+ struct au_nowait_tasks si_nowait;
+
+ /*
+ * tried sb->s_umount, but failed due to the dependency between i_mutex.
+ * rwsem for au_sbinfo is necessary.
+ */
+ struct au_rwsem si_rwsem;
+
+ /*
+ * dirty approach to protect sb->sb_inodes and ->s_files (gone) from
+ * remount.
+ */
+ au_lcnt_t si_ninodes, si_nfiles;
+
+ /* branch management */
+ unsigned int si_generation;
+
+ /* see AuSi_ flags */
+ unsigned char au_si_status;
+
+ aufs_bindex_t si_bbot;
+
+ /* dirty trick to keep br_id plus */
+ unsigned int si_last_br_id :
+ sizeof(aufs_bindex_t) * BITS_PER_BYTE - 1;
+ struct au_branch **si_branch;
+
+ /* policy to select a writable branch */
+ unsigned char si_wbr_copyup;
+ unsigned char si_wbr_create;
+ struct au_wbr_copyup_operations *si_wbr_copyup_ops;
+ struct au_wbr_create_operations *si_wbr_create_ops;
+
+ /* round robin */
+ atomic_t si_wbr_rr_next;
+
+ /* most free space */
+ struct au_wbr_mfs si_wbr_mfs;
+
+ /* File-based Hierarchical Storage Management */
+ struct au_fhsm si_fhsm;
+
+ /* mount flags */
+ /* include/asm-ia64/siginfo.h defines a macro named si_flags */
+ unsigned int si_mntflags;
+
+ /* external inode number (bitmap and translation table) */
+ vfs_readf_t si_xread;
+ vfs_writef_t si_xwrite;
+ loff_t si_ximaxent; /* max entries in a xino */
+
+ struct file *si_xib;
+ struct mutex si_xib_mtx; /* protect xib members */
+ unsigned long *si_xib_buf;
+ unsigned long si_xib_last_pindex;
+ int si_xib_next_bit;
+
+ unsigned long si_xino_jiffy;
+ unsigned long si_xino_expire;
+ /* reserved for future use */
+ /* unsigned long long si_xib_limit; */ /* Max xib file size */
+
+#ifdef CONFIG_AUFS_EXPORT
+ /* i_generation */
+ /* todo: make xigen file an array to support many inode numbers */
+ struct file *si_xigen;
+ atomic_t si_xigen_next;
+#endif
+
+ /* dirty trick to support atomic_open */
+ struct hlist_bl_head si_aopen;
+
+ /* vdir parameters */
+ unsigned long si_rdcache; /* max cache time in jiffies */
+ unsigned int si_rdblk; /* deblk size */
+ unsigned int si_rdhash; /* hash size */
+
+ /*
+ * If the number of whiteouts are larger than si_dirwh, leave all of
+ * them after au_whtmp_ren to reduce the cost of rmdir(2).
+ * future fsck.aufs or kernel thread will remove them later.
+ * Otherwise, remove all whiteouts and the dir in rmdir(2).
+ */
+ unsigned int si_dirwh;
+
+ /* pseudo_link list */
+ struct hlist_bl_head si_plink[AuPlink_NHASH];
+ wait_queue_head_t si_plink_wq;
+ spinlock_t si_plink_maint_lock;
+ pid_t si_plink_maint_pid;
+
+ /* file list */
+ struct hlist_bl_head si_files;
+
+ /* with/without getattr, brother of sb->s_d_op */
+ const struct inode_operations *si_iop_array;
+
+ /*
+ * sysfs and lifetime management.
+ * this is not a small structure and it may be a waste of memory in case
+ * of sysfs is disabled, particularly when many aufs-es are mounted.
+ * but using sysfs is majority.
+ */
+ struct kobject si_kobj;
+#ifdef CONFIG_DEBUG_FS
+ struct dentry *si_dbgaufs;
+ struct dentry *si_dbgaufs_plink;
+ struct dentry *si_dbgaufs_xib;
+#ifdef CONFIG_AUFS_EXPORT
+ struct dentry *si_dbgaufs_xigen;
+#endif
+#endif
+
+#ifdef CONFIG_AUFS_SBILIST
+ struct hlist_bl_node si_list;
+#endif
+
+ /* dirty, necessary for unmounting, sysfs and sysrq */
+ struct super_block *si_sb;
+};
+
+/* sbinfo status flags */
+/*
+ * set true when refresh_dirs() failed at remount time.
+ * then try refreshing dirs at access time again.
+ * if it is false, refreshing dirs at access time is unnecessary
+ */
+#define AuSi_FAILED_REFRESH_DIR 1
+#define AuSi_FHSM (1 << 1) /* fhsm is active now */
+#define AuSi_NO_DREVAL (1 << 2) /* disable all d_revalidate */
+
+#ifndef CONFIG_AUFS_FHSM
+#undef AuSi_FHSM
+#define AuSi_FHSM 0
+#endif
+
+static inline unsigned char au_do_ftest_si(struct au_sbinfo *sbi,
+ unsigned int flag)
+{
+ AuRwMustAnyLock(&sbi->si_rwsem);
+ return sbi->au_si_status & flag;
+}
+#define au_ftest_si(sbinfo, name) au_do_ftest_si(sbinfo, AuSi_##name)
+#define au_fset_si(sbinfo, name) do { \
+ AuRwMustWriteLock(&(sbinfo)->si_rwsem); \
+ (sbinfo)->au_si_status |= AuSi_##name; \
+} while (0)
+#define au_fclr_si(sbinfo, name) do { \
+ AuRwMustWriteLock(&(sbinfo)->si_rwsem); \
+ (sbinfo)->au_si_status &= ~AuSi_##name; \
+} while (0)
+
+/* ---------------------------------------------------------------------- */
+
+/* policy to select one among writable branches */
+#define AuWbrCopyup(sbinfo, ...) \
+ ((sbinfo)->si_wbr_copyup_ops->copyup(__VA_ARGS__))
+#define AuWbrCreate(sbinfo, ...) \
+ ((sbinfo)->si_wbr_create_ops->create(__VA_ARGS__))
+
+/* flags for si_read_lock()/aufs_read_lock()/di_read_lock() */
+#define AuLock_DW 1 /* write-lock dentry */
+#define AuLock_IR (1 << 1) /* read-lock inode */
+#define AuLock_IW (1 << 2) /* write-lock inode */
+#define AuLock_FLUSH (1 << 3) /* wait for 'nowait' tasks */
+#define AuLock_DIRS (1 << 4) /* target is a pair of dirs */
+ /* except RENAME_EXCHANGE */
+#define AuLock_NOPLM (1 << 5) /* return err in plm mode */
+#define AuLock_NOPLMW (1 << 6) /* wait for plm mode ends */
+#define AuLock_GEN (1 << 7) /* test digen/iigen */
+#define au_ftest_lock(flags, name) ((flags) & AuLock_##name)
+#define au_fset_lock(flags, name) \
+ do { (flags) |= AuLock_##name; } while (0)
+#define au_fclr_lock(flags, name) \
+ do { (flags) &= ~AuLock_##name; } while (0)
+
+/* ---------------------------------------------------------------------- */
+
+/* super.c */
+extern struct file_system_type aufs_fs_type;
+struct inode *au_iget_locked(struct super_block *sb, ino_t ino);
+typedef unsigned long long (*au_arraycb_t)(struct super_block *sb, void *array,
+ unsigned long long max, void *arg);
+void *au_array_alloc(unsigned long long *hint, au_arraycb_t cb,
+ struct super_block *sb, void *arg);
+struct inode **au_iarray_alloc(struct super_block *sb, unsigned long long *max);
+void au_iarray_free(struct inode **a, unsigned long long max);
+
+/* sbinfo.c */
+void au_si_free(struct kobject *kobj);
+int au_si_alloc(struct super_block *sb);
+int au_sbr_realloc(struct au_sbinfo *sbinfo, int nbr, int may_shrink);
+
+unsigned int au_sigen_inc(struct super_block *sb);
+aufs_bindex_t au_new_br_id(struct super_block *sb);
+
+int si_read_lock(struct super_block *sb, int flags);
+int si_write_lock(struct super_block *sb, int flags);
+int aufs_read_lock(struct dentry *dentry, int flags);
+void aufs_read_unlock(struct dentry *dentry, int flags);
+void aufs_write_lock(struct dentry *dentry);
+void aufs_write_unlock(struct dentry *dentry);
+int aufs_read_and_write_lock2(struct dentry *d1, struct dentry *d2, int flags);
+void aufs_read_and_write_unlock2(struct dentry *d1, struct dentry *d2);
+
+/* wbr_policy.c */
+extern struct au_wbr_copyup_operations au_wbr_copyup_ops[];
+extern struct au_wbr_create_operations au_wbr_create_ops[];
+int au_cpdown_dirs(struct dentry *dentry, aufs_bindex_t bdst);
+int au_wbr_nonopq(struct dentry *dentry, aufs_bindex_t bindex);
+int au_wbr_do_copyup_bu(struct dentry *dentry, aufs_bindex_t btop);
+
+/* mvdown.c */
+int au_mvdown(struct dentry *dentry, struct aufs_mvdown __user *arg);
+
+#ifdef CONFIG_AUFS_FHSM
+/* fhsm.c */
+
+static inline pid_t au_fhsm_pid(struct au_fhsm *fhsm)
+{
+ pid_t pid;
+
+ spin_lock(&fhsm->fhsm_spin);
+ pid = fhsm->fhsm_pid;
+ spin_unlock(&fhsm->fhsm_spin);
+
+ return pid;
+}
+
+void au_fhsm_wrote(struct super_block *sb, aufs_bindex_t bindex, int force);
+void au_fhsm_wrote_all(struct super_block *sb, int force);
+int au_fhsm_fd(struct super_block *sb, int oflags);
+int au_fhsm_br_alloc(struct au_branch *br);
+void au_fhsm_set_bottom(struct super_block *sb, aufs_bindex_t bindex);
+void au_fhsm_fin(struct super_block *sb);
+void au_fhsm_init(struct au_sbinfo *sbinfo);
+void au_fhsm_set(struct au_sbinfo *sbinfo, unsigned int sec);
+void au_fhsm_show(struct seq_file *seq, struct au_sbinfo *sbinfo);
+#else
+AuStubVoid(au_fhsm_wrote, struct super_block *sb, aufs_bindex_t bindex,
+ int force)
+AuStubVoid(au_fhsm_wrote_all, struct super_block *sb, int force)
+AuStub(int, au_fhsm_fd, return -EOPNOTSUPP, struct super_block *sb, int oflags)
+AuStub(pid_t, au_fhsm_pid, return 0, struct au_fhsm *fhsm)
+AuStubInt0(au_fhsm_br_alloc, struct au_branch *br)
+AuStubVoid(au_fhsm_set_bottom, struct super_block *sb, aufs_bindex_t bindex)
+AuStubVoid(au_fhsm_fin, struct super_block *sb)
+AuStubVoid(au_fhsm_init, struct au_sbinfo *sbinfo)
+AuStubVoid(au_fhsm_set, struct au_sbinfo *sbinfo, unsigned int sec)
+AuStubVoid(au_fhsm_show, struct seq_file *seq, struct au_sbinfo *sbinfo)
+#endif
+
+/* ---------------------------------------------------------------------- */
+
+static inline struct au_sbinfo *au_sbi(struct super_block *sb)
+{
+ return sb->s_fs_info;
+}
+
+/* ---------------------------------------------------------------------- */
+
+#ifdef CONFIG_AUFS_EXPORT
+int au_test_nfsd(void);
+void au_export_init(struct super_block *sb);
+void au_xigen_inc(struct inode *inode);
+int au_xigen_new(struct inode *inode);
+int au_xigen_set(struct super_block *sb, struct path *path);
+void au_xigen_clr(struct super_block *sb);
+
+static inline int au_busy_or_stale(void)
+{
+ if (!au_test_nfsd())
+ return -EBUSY;
+ return -ESTALE;
+}
+#else
+AuStubInt0(au_test_nfsd, void)
+AuStubVoid(au_export_init, struct super_block *sb)
+AuStubVoid(au_xigen_inc, struct inode *inode)
+AuStubInt0(au_xigen_new, struct inode *inode)
+AuStubInt0(au_xigen_set, struct super_block *sb, struct path *path)
+AuStubVoid(au_xigen_clr, struct super_block *sb)
+AuStub(int, au_busy_or_stale, return -EBUSY, void)
+#endif /* CONFIG_AUFS_EXPORT */
+
+/* ---------------------------------------------------------------------- */
+
+#ifdef CONFIG_AUFS_SBILIST
+/* module.c */
+extern struct hlist_bl_head au_sbilist;
+
+static inline void au_sbilist_init(void)
+{
+ INIT_HLIST_BL_HEAD(&au_sbilist);
+}
+
+static inline void au_sbilist_add(struct super_block *sb)
+{
+ au_hbl_add(&au_sbi(sb)->si_list, &au_sbilist);
+}
+
+static inline void au_sbilist_del(struct super_block *sb)
+{
+ au_hbl_del(&au_sbi(sb)->si_list, &au_sbilist);
+}
+
+#ifdef CONFIG_AUFS_MAGIC_SYSRQ
+static inline void au_sbilist_lock(void)
+{
+ hlist_bl_lock(&au_sbilist);
+}
+
+static inline void au_sbilist_unlock(void)
+{
+ hlist_bl_unlock(&au_sbilist);
+}
+#define AuGFP_SBILIST GFP_ATOMIC
+#else
+AuStubVoid(au_sbilist_lock, void)
+AuStubVoid(au_sbilist_unlock, void)
+#define AuGFP_SBILIST GFP_NOFS
+#endif /* CONFIG_AUFS_MAGIC_SYSRQ */
+#else
+AuStubVoid(au_sbilist_init, void)
+AuStubVoid(au_sbilist_add, struct super_block *sb)
+AuStubVoid(au_sbilist_del, struct super_block *sb)
+AuStubVoid(au_sbilist_lock, void)
+AuStubVoid(au_sbilist_unlock, void)
+#define AuGFP_SBILIST GFP_NOFS
+#endif
+
+/* ---------------------------------------------------------------------- */
+
+static inline void dbgaufs_si_null(struct au_sbinfo *sbinfo)
+{
+ /*
+ * This function is a dynamic '__init' function actually,
+ * so the tiny check for si_rwsem is unnecessary.
+ */
+ /* AuRwMustWriteLock(&sbinfo->si_rwsem); */
+#ifdef CONFIG_DEBUG_FS
+ sbinfo->si_dbgaufs = NULL;
+ sbinfo->si_dbgaufs_plink = NULL;
+ sbinfo->si_dbgaufs_xib = NULL;
+#ifdef CONFIG_AUFS_EXPORT
+ sbinfo->si_dbgaufs_xigen = NULL;
+#endif
+#endif
+}
+
+/* ---------------------------------------------------------------------- */
+
+/* current->atomic_flags */
+/* this value should never corrupt the ones defined in linux/sched.h */
+#define PFA_AUFS 0x10
+
+TASK_PFA_TEST(AUFS, test_aufs) /* task_test_aufs */
+TASK_PFA_SET(AUFS, aufs) /* task_set_aufs */
+TASK_PFA_CLEAR(AUFS, aufs) /* task_clear_aufs */
+
+static inline int si_pid_test(struct super_block *sb)
+{
+ return !!task_test_aufs(current);
+}
+
+static inline void si_pid_clr(struct super_block *sb)
+{
+ AuDebugOn(!task_test_aufs(current));
+ task_clear_aufs(current);
+}
+
+static inline void si_pid_set(struct super_block *sb)
+{
+ AuDebugOn(task_test_aufs(current));
+ task_set_aufs(current);
+}
+
+/* ---------------------------------------------------------------------- */
+
+/* lock superblock. mainly for entry point functions */
+#define __si_read_lock(sb) au_rw_read_lock(&au_sbi(sb)->si_rwsem)
+#define __si_write_lock(sb) au_rw_write_lock(&au_sbi(sb)->si_rwsem)
+#define __si_read_trylock(sb) au_rw_read_trylock(&au_sbi(sb)->si_rwsem)
+#define __si_write_trylock(sb) au_rw_write_trylock(&au_sbi(sb)->si_rwsem)
+/*
+#define __si_read_trylock_nested(sb) \
+ au_rw_read_trylock_nested(&au_sbi(sb)->si_rwsem)
+#define __si_write_trylock_nested(sb) \
+ au_rw_write_trylock_nested(&au_sbi(sb)->si_rwsem)
+*/
+
+#define __si_read_unlock(sb) au_rw_read_unlock(&au_sbi(sb)->si_rwsem)
+#define __si_write_unlock(sb) au_rw_write_unlock(&au_sbi(sb)->si_rwsem)
+#define __si_downgrade_lock(sb) au_rw_dgrade_lock(&au_sbi(sb)->si_rwsem)
+
+#define SiMustNoWaiters(sb) AuRwMustNoWaiters(&au_sbi(sb)->si_rwsem)
+#define SiMustAnyLock(sb) AuRwMustAnyLock(&au_sbi(sb)->si_rwsem)
+#define SiMustWriteLock(sb) AuRwMustWriteLock(&au_sbi(sb)->si_rwsem)
+
+static inline void si_noflush_read_lock(struct super_block *sb)
+{
+ __si_read_lock(sb);
+ si_pid_set(sb);
+}
+
+static inline int si_noflush_read_trylock(struct super_block *sb)
+{
+ int locked;
+
+ locked = __si_read_trylock(sb);
+ if (locked)
+ si_pid_set(sb);
+ return locked;
+}
+
+static inline void si_noflush_write_lock(struct super_block *sb)
+{
+ __si_write_lock(sb);
+ si_pid_set(sb);
+}
+
+static inline int si_noflush_write_trylock(struct super_block *sb)
+{
+ int locked;
+
+ locked = __si_write_trylock(sb);
+ if (locked)
+ si_pid_set(sb);
+ return locked;
+}
+
+#if 0 /* reserved */
+static inline int si_read_trylock(struct super_block *sb, int flags)
+{
+ if (au_ftest_lock(flags, FLUSH))
+ au_nwt_flush(&au_sbi(sb)->si_nowait);
+ return si_noflush_read_trylock(sb);
+}
+#endif
+
+static inline void si_read_unlock(struct super_block *sb)
+{
+ si_pid_clr(sb);
+ __si_read_unlock(sb);
+}
+
+#if 0 /* reserved */
+static inline int si_write_trylock(struct super_block *sb, int flags)
+{
+ if (au_ftest_lock(flags, FLUSH))
+ au_nwt_flush(&au_sbi(sb)->si_nowait);
+ return si_noflush_write_trylock(sb);
+}
+#endif
+
+static inline void si_write_unlock(struct super_block *sb)
+{
+ si_pid_clr(sb);
+ __si_write_unlock(sb);
+}
+
+#if 0 /* reserved */
+static inline void si_downgrade_lock(struct super_block *sb)
+{
+ __si_downgrade_lock(sb);
+}
+#endif
+
+/* ---------------------------------------------------------------------- */
+
+static inline aufs_bindex_t au_sbbot(struct super_block *sb)
+{
+ SiMustAnyLock(sb);
+ return au_sbi(sb)->si_bbot;
+}
+
+static inline unsigned int au_mntflags(struct super_block *sb)
+{
+ SiMustAnyLock(sb);
+ return au_sbi(sb)->si_mntflags;
+}
+
+static inline unsigned int au_sigen(struct super_block *sb)
+{
+ SiMustAnyLock(sb);
+ return au_sbi(sb)->si_generation;
+}
+
+static inline struct au_branch *au_sbr(struct super_block *sb,
+ aufs_bindex_t bindex)
+{
+ SiMustAnyLock(sb);
+ return au_sbi(sb)->si_branch[0 + bindex];
+}
+
+static inline loff_t au_xi_maxent(struct super_block *sb)
+{
+ SiMustAnyLock(sb);
+ return au_sbi(sb)->si_ximaxent;
+}
+
+#endif /* __KERNEL__ */
+#endif /* __AUFS_SUPER_H__ */
generated by cgit 1.2.3-korg (git 2.39.0) at 2024-04-27 16:13:16 +0000