--- /dev/null
-int sb_min_blocksize(struct super_block *sb, int size);
+ /* SPDX-License-Identifier: GPL-2.0 */
+ #ifndef _LINUX_FS_SUPER_H
+ #define _LINUX_FS_SUPER_H
+
+ #include <linux/fs/super_types.h>
+ #include <linux/unicode.h>
+
+ /*
+ * These are internal functions, please use sb_start_{write,pagefault,intwrite}
+ * instead.
+ */
+ static inline void __sb_end_write(struct super_block *sb, int level)
+ {
+ percpu_up_read(sb->s_writers.rw_sem + level - 1);
+ }
+
+ static inline void __sb_start_write(struct super_block *sb, int level)
+ {
+ percpu_down_read_freezable(sb->s_writers.rw_sem + level - 1, true);
+ }
+
+ static inline bool __sb_start_write_trylock(struct super_block *sb, int level)
+ {
+ return percpu_down_read_trylock(sb->s_writers.rw_sem + level - 1);
+ }
+
+ #define __sb_writers_acquired(sb, lev) \
+ percpu_rwsem_acquire(&(sb)->s_writers.rw_sem[(lev) - 1], 1, _THIS_IP_)
+ #define __sb_writers_release(sb, lev) \
+ percpu_rwsem_release(&(sb)->s_writers.rw_sem[(lev) - 1], _THIS_IP_)
+
+ /**
+ * __sb_write_started - check if sb freeze level is held
+ * @sb: the super we write to
+ * @level: the freeze level
+ *
+ * * > 0 - sb freeze level is held
+ * * 0 - sb freeze level is not held
+ * * < 0 - !CONFIG_LOCKDEP/LOCK_STATE_UNKNOWN
+ */
+ static inline int __sb_write_started(const struct super_block *sb, int level)
+ {
+ return lockdep_is_held_type(sb->s_writers.rw_sem + level - 1, 1);
+ }
+
+ /**
+ * sb_write_started - check if SB_FREEZE_WRITE is held
+ * @sb: the super we write to
+ *
+ * May be false positive with !CONFIG_LOCKDEP/LOCK_STATE_UNKNOWN.
+ */
+ static inline bool sb_write_started(const struct super_block *sb)
+ {
+ return __sb_write_started(sb, SB_FREEZE_WRITE);
+ }
+
+ /**
+ * sb_write_not_started - check if SB_FREEZE_WRITE is not held
+ * @sb: the super we write to
+ *
+ * May be false positive with !CONFIG_LOCKDEP/LOCK_STATE_UNKNOWN.
+ */
+ static inline bool sb_write_not_started(const struct super_block *sb)
+ {
+ return __sb_write_started(sb, SB_FREEZE_WRITE) <= 0;
+ }
+
+ /**
+ * sb_end_write - drop write access to a superblock
+ * @sb: the super we wrote to
+ *
+ * Decrement number of writers to the filesystem. Wake up possible waiters
+ * wanting to freeze the filesystem.
+ */
+ static inline void sb_end_write(struct super_block *sb)
+ {
+ __sb_end_write(sb, SB_FREEZE_WRITE);
+ }
+
+ /**
+ * sb_end_pagefault - drop write access to a superblock from a page fault
+ * @sb: the super we wrote to
+ *
+ * Decrement number of processes handling write page fault to the filesystem.
+ * Wake up possible waiters wanting to freeze the filesystem.
+ */
+ static inline void sb_end_pagefault(struct super_block *sb)
+ {
+ __sb_end_write(sb, SB_FREEZE_PAGEFAULT);
+ }
+
+ /**
+ * sb_end_intwrite - drop write access to a superblock for internal fs purposes
+ * @sb: the super we wrote to
+ *
+ * Decrement fs-internal number of writers to the filesystem. Wake up possible
+ * waiters wanting to freeze the filesystem.
+ */
+ static inline void sb_end_intwrite(struct super_block *sb)
+ {
+ __sb_end_write(sb, SB_FREEZE_FS);
+ }
+
+ /**
+ * sb_start_write - get write access to a superblock
+ * @sb: the super we write to
+ *
+ * When a process wants to write data or metadata to a file system (i.e. dirty
+ * a page or an inode), it should embed the operation in a sb_start_write() -
+ * sb_end_write() pair to get exclusion against file system freezing. This
+ * function increments number of writers preventing freezing. If the file
+ * system is already frozen, the function waits until the file system is
+ * thawed.
+ *
+ * Since freeze protection behaves as a lock, users have to preserve
+ * ordering of freeze protection and other filesystem locks. Generally,
+ * freeze protection should be the outermost lock. In particular, we have:
+ *
+ * sb_start_write
+ * -> i_rwsem (write path, truncate, directory ops, ...)
+ * -> s_umount (freeze_super, thaw_super)
+ */
+ static inline void sb_start_write(struct super_block *sb)
+ {
+ __sb_start_write(sb, SB_FREEZE_WRITE);
+ }
+
+ static inline bool sb_start_write_trylock(struct super_block *sb)
+ {
+ return __sb_start_write_trylock(sb, SB_FREEZE_WRITE);
+ }
+
+ /**
+ * sb_start_pagefault - get write access to a superblock from a page fault
+ * @sb: the super we write to
+ *
+ * When a process starts handling write page fault, it should embed the
+ * operation into sb_start_pagefault() - sb_end_pagefault() pair to get
+ * exclusion against file system freezing. This is needed since the page fault
+ * is going to dirty a page. This function increments number of running page
+ * faults preventing freezing. If the file system is already frozen, the
+ * function waits until the file system is thawed.
+ *
+ * Since page fault freeze protection behaves as a lock, users have to preserve
+ * ordering of freeze protection and other filesystem locks. It is advised to
+ * put sb_start_pagefault() close to mmap_lock in lock ordering. Page fault
+ * handling code implies lock dependency:
+ *
+ * mmap_lock
+ * -> sb_start_pagefault
+ */
+ static inline void sb_start_pagefault(struct super_block *sb)
+ {
+ __sb_start_write(sb, SB_FREEZE_PAGEFAULT);
+ }
+
+ /**
+ * sb_start_intwrite - get write access to a superblock for internal fs purposes
+ * @sb: the super we write to
+ *
+ * This is the third level of protection against filesystem freezing. It is
+ * free for use by a filesystem. The only requirement is that it must rank
+ * below sb_start_pagefault.
+ *
+ * For example filesystem can call sb_start_intwrite() when starting a
+ * transaction which somewhat eases handling of freezing for internal sources
+ * of filesystem changes (internal fs threads, discarding preallocation on file
+ * close, etc.).
+ */
+ static inline void sb_start_intwrite(struct super_block *sb)
+ {
+ __sb_start_write(sb, SB_FREEZE_FS);
+ }
+
+ static inline bool sb_start_intwrite_trylock(struct super_block *sb)
+ {
+ return __sb_start_write_trylock(sb, SB_FREEZE_FS);
+ }
+
+ static inline bool sb_rdonly(const struct super_block *sb)
+ {
+ return sb->s_flags & SB_RDONLY;
+ }
+
+ static inline bool sb_is_blkdev_sb(struct super_block *sb)
+ {
+ return IS_ENABLED(CONFIG_BLOCK) && sb == blockdev_superblock;
+ }
+
+ #if IS_ENABLED(CONFIG_UNICODE)
+ static inline struct unicode_map *sb_encoding(const struct super_block *sb)
+ {
+ return sb->s_encoding;
+ }
+
+ /* Compare if two super blocks have the same encoding and flags */
+ static inline bool sb_same_encoding(const struct super_block *sb1,
+ const struct super_block *sb2)
+ {
+ if (sb1->s_encoding == sb2->s_encoding)
+ return true;
+
+ return (sb1->s_encoding && sb2->s_encoding &&
+ (sb1->s_encoding->version == sb2->s_encoding->version) &&
+ (sb1->s_encoding_flags == sb2->s_encoding_flags));
+ }
+ #else
+ static inline struct unicode_map *sb_encoding(const struct super_block *sb)
+ {
+ return NULL;
+ }
+
+ static inline bool sb_same_encoding(const struct super_block *sb1,
+ const struct super_block *sb2)
+ {
+ return true;
+ }
+ #endif
+
+ static inline bool sb_has_encoding(const struct super_block *sb)
+ {
+ return !!sb_encoding(sb);
+ }
+
+ int sb_set_blocksize(struct super_block *sb, int size);
++int __must_check sb_min_blocksize(struct super_block *sb, int size);
+
+ int freeze_super(struct super_block *super, enum freeze_holder who,
+ const void *freeze_owner);
+ int thaw_super(struct super_block *super, enum freeze_holder who,
+ const void *freeze_owner);
+
+ #endif /* _LINUX_FS_SUPER_H */
--- /dev/null
+ /* SPDX-License-Identifier: GPL-2.0 */
+ #ifndef _LINUX_FS_SUPER_TYPES_H
+ #define _LINUX_FS_SUPER_TYPES_H
+
+ #include <linux/fs_dirent.h>
+ #include <linux/errseq.h>
+ #include <linux/list_lru.h>
+ #include <linux/list.h>
+ #include <linux/list_bl.h>
+ #include <linux/llist.h>
+ #include <linux/uidgid.h>
+ #include <linux/uuid.h>
+ #include <linux/percpu-rwsem.h>
+ #include <linux/workqueue_types.h>
+ #include <linux/quota.h>
+
+ struct backing_dev_info;
+ struct block_device;
+ struct dentry;
+ struct dentry_operations;
+ struct dquot_operations;
+ struct export_operations;
+ struct file;
+ struct file_system_type;
+ struct fscrypt_operations;
+ struct fsnotify_sb_info;
+ struct fsverity_operations;
+ struct kstatfs;
+ struct mount;
+ struct mtd_info;
+ struct quotactl_ops;
+ struct shrinker;
+ struct unicode_map;
+ struct user_namespace;
+ struct workqueue_struct;
+ struct writeback_control;
+ struct xattr_handler;
+
+ extern struct super_block *blockdev_superblock;
+
+ /* Possible states of 'frozen' field */
+ enum {
+ SB_UNFROZEN = 0, /* FS is unfrozen */
+ SB_FREEZE_WRITE = 1, /* Writes, dir ops, ioctls frozen */
+ SB_FREEZE_PAGEFAULT = 2, /* Page faults stopped as well */
+ SB_FREEZE_FS = 3, /* For internal FS use (e.g. to stop internal threads if needed) */
+ SB_FREEZE_COMPLETE = 4, /* ->freeze_fs finished successfully */
+ };
+
+ #define SB_FREEZE_LEVELS (SB_FREEZE_COMPLETE - 1)
+
+ struct sb_writers {
+ unsigned short frozen; /* Is sb frozen? */
+ int freeze_kcount; /* How many kernel freeze requests? */
+ int freeze_ucount; /* How many userspace freeze requests? */
+ const void *freeze_owner; /* Owner of the freeze */
+ struct percpu_rw_semaphore rw_sem[SB_FREEZE_LEVELS];
+ };
+
+ /**
+ * enum freeze_holder - holder of the freeze
+ * @FREEZE_HOLDER_KERNEL: kernel wants to freeze or thaw filesystem
+ * @FREEZE_HOLDER_USERSPACE: userspace wants to freeze or thaw filesystem
+ * @FREEZE_MAY_NEST: whether nesting freeze and thaw requests is allowed
+ * @FREEZE_EXCL: a freeze that can only be undone by the owner
+ *
+ * Indicate who the owner of the freeze or thaw request is and whether
+ * the freeze needs to be exclusive or can nest.
+ * Without @FREEZE_MAY_NEST, multiple freeze and thaw requests from the
+ * same holder aren't allowed. It is however allowed to hold a single
+ * @FREEZE_HOLDER_USERSPACE and a single @FREEZE_HOLDER_KERNEL freeze at
+ * the same time. This is relied upon by some filesystems during online
+ * repair or similar.
+ */
+ enum freeze_holder {
+ FREEZE_HOLDER_KERNEL = (1U << 0),
+ FREEZE_HOLDER_USERSPACE = (1U << 1),
+ FREEZE_MAY_NEST = (1U << 2),
+ FREEZE_EXCL = (1U << 3),
+ };
+
+ struct super_operations {
+ struct inode *(*alloc_inode)(struct super_block *sb);
+ void (*destroy_inode)(struct inode *inode);
+ void (*free_inode)(struct inode *inode);
+ void (*dirty_inode)(struct inode *inode, int flags);
+ int (*write_inode)(struct inode *inode, struct writeback_control *wbc);
+ int (*drop_inode)(struct inode *inode);
+ void (*evict_inode)(struct inode *inode);
+ void (*put_super)(struct super_block *sb);
+ int (*sync_fs)(struct super_block *sb, int wait);
+ int (*freeze_super)(struct super_block *sb, enum freeze_holder who,
+ const void *owner);
+ int (*freeze_fs)(struct super_block *sb);
+ int (*thaw_super)(struct super_block *sb, enum freeze_holder who,
+ const void *owner);
+ int (*unfreeze_fs)(struct super_block *sb);
+ int (*statfs)(struct dentry *dentry, struct kstatfs *kstatfs);
+ int (*remount_fs) (struct super_block *, int *, char *);
+ void (*umount_begin)(struct super_block *sb);
+
+ int (*show_options)(struct seq_file *seq, struct dentry *dentry);
+ int (*show_devname)(struct seq_file *seq, struct dentry *dentry);
+ int (*show_path)(struct seq_file *seq, struct dentry *dentry);
+ int (*show_stats)(struct seq_file *seq, struct dentry *dentry);
+ #ifdef CONFIG_QUOTA
+ ssize_t (*quota_read)(struct super_block *sb, int type, char *data,
+ size_t len, loff_t off);
+ ssize_t (*quota_write)(struct super_block *sb, int type,
+ const char *data, size_t len, loff_t off);
+ struct dquot __rcu **(*get_dquots)(struct inode *inode);
+ #endif
+ long (*nr_cached_objects)(struct super_block *sb,
+ struct shrink_control *sc);
+ long (*free_cached_objects)(struct super_block *sb,
+ struct shrink_control *sc);
+ /*
+ * If a filesystem can support graceful removal of a device and
+ * continue read-write operations, implement this callback.
+ *
+ * Return 0 if the filesystem can continue read-write.
+ * Non-zero return value or no such callback means the fs will be shutdown
+ * as usual.
+ */
+ int (*remove_bdev)(struct super_block *sb, struct block_device *bdev);
+ void (*shutdown)(struct super_block *sb);
+ };
+
+ struct super_block {
+ struct list_head s_list; /* Keep this first */
+ dev_t s_dev; /* search index; _not_ kdev_t */
+ unsigned char s_blocksize_bits;
+ unsigned long s_blocksize;
+ loff_t s_maxbytes; /* Max file size */
+ struct file_system_type *s_type;
+ const struct super_operations *s_op;
+ const struct dquot_operations *dq_op;
+ const struct quotactl_ops *s_qcop;
+ const struct export_operations *s_export_op;
+ unsigned long s_flags;
+ unsigned long s_iflags; /* internal SB_I_* flags */
+ unsigned long s_magic;
+ struct dentry *s_root;
+ struct rw_semaphore s_umount;
+ int s_count;
+ atomic_t s_active;
+ #ifdef CONFIG_SECURITY
+ void *s_security;
+ #endif
+ const struct xattr_handler *const *s_xattr;
+ #ifdef CONFIG_FS_ENCRYPTION
+ const struct fscrypt_operations *s_cop;
+ struct fscrypt_keyring *s_master_keys; /* master crypto keys in use */
+ #endif
+ #ifdef CONFIG_FS_VERITY
+ const struct fsverity_operations *s_vop;
+ #endif
+ #if IS_ENABLED(CONFIG_UNICODE)
+ struct unicode_map *s_encoding;
+ __u16 s_encoding_flags;
+ #endif
+ struct hlist_bl_head s_roots; /* alternate root dentries for NFS */
+ struct mount *s_mounts; /* list of mounts; _not_ for fs use */
+ struct block_device *s_bdev; /* can go away once we use an accessor for @s_bdev_file */
+ struct file *s_bdev_file;
+ struct backing_dev_info *s_bdi;
+ struct mtd_info *s_mtd;
+ struct hlist_node s_instances;
+ unsigned int s_quota_types; /* Bitmask of supported quota types */
+ struct quota_info s_dquot; /* Diskquota specific options */
+
+ struct sb_writers s_writers;
+
+ /*
+ * Keep s_fs_info, s_time_gran, s_fsnotify_mask, and
+ * s_fsnotify_info together for cache efficiency. They are frequently
+ * accessed and rarely modified.
+ */
+ void *s_fs_info; /* Filesystem private info */
+
+ /* Granularity of c/m/atime in ns (cannot be worse than a second) */
+ u32 s_time_gran;
+ /* Time limits for c/m/atime in seconds */
+ time64_t s_time_min;
+ time64_t s_time_max;
+ #ifdef CONFIG_FSNOTIFY
+ u32 s_fsnotify_mask;
+ struct fsnotify_sb_info *s_fsnotify_info;
+ #endif
+
+ /*
+ * q: why are s_id and s_sysfs_name not the same? both are human
+ * readable strings that identify the filesystem
+ * a: s_id is allowed to change at runtime; it's used in log messages,
+ * and we want to when a device starts out as single device (s_id is dev
+ * name) but then a device is hot added and we have to switch to
+ * identifying it by UUID
+ * but s_sysfs_name is a handle for programmatic access, and can't
+ * change at runtime
+ */
+ char s_id[32]; /* Informational name */
+ uuid_t s_uuid; /* UUID */
+ u8 s_uuid_len; /* Default 16, possibly smaller for weird filesystems */
+
+ /* if set, fs shows up under sysfs at /sys/fs/$FSTYP/s_sysfs_name */
+ char s_sysfs_name[UUID_STRING_LEN + 1];
+
+ unsigned int s_max_links;
+ unsigned int s_d_flags; /* default d_flags for dentries */
+
+ /*
+ * The next field is for VFS *only*. No filesystems have any business
+ * even looking at it. You had been warned.
+ */
+ struct mutex s_vfs_rename_mutex; /* Kludge */
+
+ /*
+ * Filesystem subtype. If non-empty the filesystem type field
+ * in /proc/mounts will be "type.subtype"
+ */
+ const char *s_subtype;
+
+ const struct dentry_operations *__s_d_op; /* default d_op for dentries */
+
+ struct shrinker *s_shrink; /* per-sb shrinker handle */
+
+ /* Number of inodes with nlink == 0 but still referenced */
+ atomic_long_t s_remove_count;
+
+ /* Read-only state of the superblock is being changed */
+ int s_readonly_remount;
+
+ /* per-sb errseq_t for reporting writeback errors via syncfs */
+ errseq_t s_wb_err;
+
+ /* AIO completions deferred from interrupt context */
+ struct workqueue_struct *s_dio_done_wq;
+ struct hlist_head s_pins;
+
+ /*
+ * Owning user namespace and default context in which to
+ * interpret filesystem uids, gids, quotas, device nodes,
+ * xattrs and security labels.
+ */
+ struct user_namespace *s_user_ns;
+
+ /*
+ * The list_lru structure is essentially just a pointer to a table
+ * of per-node lru lists, each of which has its own spinlock.
+ * There is no need to put them into separate cachelines.
+ */
+ struct list_lru s_dentry_lru;
+ struct list_lru s_inode_lru;
+ struct rcu_head rcu;
+ struct work_struct destroy_work;
+
+ struct mutex s_sync_lock; /* sync serialisation lock */
+
+ /*
+ * Indicates how deep in a filesystem stack this SB is
+ */
+ int s_stack_depth;
+
+ /* s_inode_list_lock protects s_inodes */
+ spinlock_t s_inode_list_lock ____cacheline_aligned_in_smp;
+ struct list_head s_inodes; /* all inodes */
+
+ spinlock_t s_inode_wblist_lock;
+ struct list_head s_inodes_wb; /* writeback inodes */
++ long s_min_writeback_pages;
+ } __randomize_layout;
+
+ /*
+ * sb->s_flags. Note that these mirror the equivalent MS_* flags where
+ * represented in both.
+ */
+ #define SB_RDONLY BIT(0) /* Mount read-only */
+ #define SB_NOSUID BIT(1) /* Ignore suid and sgid bits */
+ #define SB_NODEV BIT(2) /* Disallow access to device special files */
+ #define SB_NOEXEC BIT(3) /* Disallow program execution */
+ #define SB_SYNCHRONOUS BIT(4) /* Writes are synced at once */
+ #define SB_MANDLOCK BIT(6) /* Allow mandatory locks on an FS */
+ #define SB_DIRSYNC BIT(7) /* Directory modifications are synchronous */
+ #define SB_NOATIME BIT(10) /* Do not update access times. */
+ #define SB_NODIRATIME BIT(11) /* Do not update directory access times */
+ #define SB_SILENT BIT(15)
+ #define SB_POSIXACL BIT(16) /* Supports POSIX ACLs */
+ #define SB_INLINECRYPT BIT(17) /* Use blk-crypto for encrypted files */
+ #define SB_KERNMOUNT BIT(22) /* this is a kern_mount call */
+ #define SB_I_VERSION BIT(23) /* Update inode I_version field */
+ #define SB_LAZYTIME BIT(25) /* Update the on-disk [acm]times lazily */
+
+ /* These sb flags are internal to the kernel */
+ #define SB_DEAD BIT(21)
+ #define SB_DYING BIT(24)
+ #define SB_FORCE BIT(27)
+ #define SB_NOSEC BIT(28)
+ #define SB_BORN BIT(29)
+ #define SB_ACTIVE BIT(30)
+ #define SB_NOUSER BIT(31)
+
+ /* These flags relate to encoding and casefolding */
+ #define SB_ENC_STRICT_MODE_FL (1 << 0)
+ #define SB_ENC_NO_COMPAT_FALLBACK_FL (1 << 1)
+
+ #define sb_has_strict_encoding(sb) \
+ (sb->s_encoding_flags & SB_ENC_STRICT_MODE_FL)
+
+ #if IS_ENABLED(CONFIG_UNICODE)
+ #define sb_no_casefold_compat_fallback(sb) \
+ (sb->s_encoding_flags & SB_ENC_NO_COMPAT_FALLBACK_FL)
+ #else
+ #define sb_no_casefold_compat_fallback(sb) (1)
+ #endif
+
+ /* sb->s_iflags */
+ #define SB_I_CGROUPWB 0x00000001 /* cgroup-aware writeback enabled */
+ #define SB_I_NOEXEC 0x00000002 /* Ignore executables on this fs */
+ #define SB_I_NODEV 0x00000004 /* Ignore devices on this fs */
+ #define SB_I_STABLE_WRITES 0x00000008 /* don't modify blks until WB is done */
+
+ /* sb->s_iflags to limit user namespace mounts */
+ #define SB_I_USERNS_VISIBLE 0x00000010 /* fstype already mounted */
+ #define SB_I_IMA_UNVERIFIABLE_SIGNATURE 0x00000020
+ #define SB_I_UNTRUSTED_MOUNTER 0x00000040
+ #define SB_I_EVM_HMAC_UNSUPPORTED 0x00000080
+
+ #define SB_I_SKIP_SYNC 0x00000100 /* Skip superblock at global sync */
+ #define SB_I_PERSB_BDI 0x00000200 /* has a per-sb bdi */
+ #define SB_I_TS_EXPIRY_WARNED 0x00000400 /* warned about timestamp range expiry */
+ #define SB_I_RETIRED 0x00000800 /* superblock shouldn't be reused */
+ #define SB_I_NOUMASK 0x00001000 /* VFS does not apply umask */
+ #define SB_I_NOIDMAP 0x00002000 /* No idmapped mounts on this superblock */
+ #define SB_I_ALLOW_HSM 0x00004000 /* Allow HSM events on this superblock */
+
+ #endif /* _LINUX_FS_SUPER_TYPES_H */
projects / thirdparty / linux.git / commitdiff
