mount.h 3.9 KB

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  1. /* SPDX-License-Identifier: GPL-2.0 */
  2. /*
  3. *
  4. * Definitions for mount interface. This describes the in the kernel build
  5. * linkedlist with mounted filesystems.
  6. *
  7. * Author: Marco van Wieringen <mvw@planets.elm.net>
  8. *
  9. */
  10. #ifndef _LINUX_MOUNT_H
  11. #define _LINUX_MOUNT_H
  12. #include <linux/types.h>
  13. #include <linux/list.h>
  14. #include <linux/nodemask.h>
  15. #include <linux/spinlock.h>
  16. #include <linux/seqlock.h>
  17. #include <linux/atomic.h>
  18. #include <linux/android_kabi.h>
  19. struct super_block;
  20. struct vfsmount;
  21. struct dentry;
  22. struct mnt_namespace;
  23. struct fs_context;
  24. #define MNT_NOSUID 0x01
  25. #define MNT_NODEV 0x02
  26. #define MNT_NOEXEC 0x04
  27. #define MNT_NOATIME 0x08
  28. #define MNT_NODIRATIME 0x10
  29. #define MNT_RELATIME 0x20
  30. #define MNT_READONLY 0x40 /* does the user want this to be r/o? */
  31. #define MNT_NOSYMFOLLOW 0x80
  32. #define MNT_SHRINKABLE 0x100
  33. #define MNT_WRITE_HOLD 0x200
  34. #define MNT_SHARED 0x1000 /* if the vfsmount is a shared mount */
  35. #define MNT_UNBINDABLE 0x2000 /* if the vfsmount is a unbindable mount */
  36. /*
  37. * MNT_SHARED_MASK is the set of flags that should be cleared when a
  38. * mount becomes shared. Currently, this is only the flag that says a
  39. * mount cannot be bind mounted, since this is how we create a mount
  40. * that shares events with another mount. If you add a new MNT_*
  41. * flag, consider how it interacts with shared mounts.
  42. */
  43. #define MNT_SHARED_MASK (MNT_UNBINDABLE)
  44. #define MNT_USER_SETTABLE_MASK (MNT_NOSUID | MNT_NODEV | MNT_NOEXEC \
  45. | MNT_NOATIME | MNT_NODIRATIME | MNT_RELATIME \
  46. | MNT_READONLY | MNT_NOSYMFOLLOW)
  47. #define MNT_ATIME_MASK (MNT_NOATIME | MNT_NODIRATIME | MNT_RELATIME )
  48. #define MNT_INTERNAL_FLAGS (MNT_SHARED | MNT_WRITE_HOLD | MNT_INTERNAL | \
  49. MNT_DOOMED | MNT_SYNC_UMOUNT | MNT_MARKED | \
  50. MNT_CURSOR)
  51. #define MNT_INTERNAL 0x4000
  52. #define MNT_LOCK_ATIME 0x040000
  53. #define MNT_LOCK_NOEXEC 0x080000
  54. #define MNT_LOCK_NOSUID 0x100000
  55. #define MNT_LOCK_NODEV 0x200000
  56. #define MNT_LOCK_READONLY 0x400000
  57. #define MNT_LOCKED 0x800000
  58. #define MNT_DOOMED 0x1000000
  59. #define MNT_SYNC_UMOUNT 0x2000000
  60. #define MNT_MARKED 0x4000000
  61. #define MNT_UMOUNT 0x8000000
  62. #define MNT_CURSOR 0x10000000
  63. struct vfsmount {
  64. struct dentry *mnt_root; /* root of the mounted tree */
  65. struct super_block *mnt_sb; /* pointer to superblock */
  66. int mnt_flags;
  67. ANDROID_KABI_RESERVE(1);
  68. ANDROID_KABI_RESERVE(2);
  69. ANDROID_KABI_RESERVE(3);
  70. ANDROID_KABI_RESERVE(4);
  71. } __randomize_layout;
  72. struct file; /* forward dec */
  73. struct path;
  74. extern int mnt_want_write(struct vfsmount *mnt);
  75. extern int mnt_want_write_file(struct file *file);
  76. extern int mnt_clone_write(struct vfsmount *mnt);
  77. extern void mnt_drop_write(struct vfsmount *mnt);
  78. extern void mnt_drop_write_file(struct file *file);
  79. extern void mntput(struct vfsmount *mnt);
  80. extern struct vfsmount *mntget(struct vfsmount *mnt);
  81. extern struct vfsmount *mnt_clone_internal(const struct path *path);
  82. extern bool __mnt_is_readonly(struct vfsmount *mnt);
  83. extern bool mnt_may_suid(struct vfsmount *mnt);
  84. struct path;
  85. extern struct vfsmount *clone_private_mount(const struct path *path);
  86. extern int __mnt_want_write(struct vfsmount *);
  87. extern void __mnt_drop_write(struct vfsmount *);
  88. struct file_system_type;
  89. extern struct vfsmount *fc_mount(struct fs_context *fc);
  90. extern struct vfsmount *vfs_create_mount(struct fs_context *fc);
  91. extern struct vfsmount *vfs_kern_mount(struct file_system_type *type,
  92. int flags, const char *name,
  93. void *data);
  94. extern struct vfsmount *vfs_submount(const struct dentry *mountpoint,
  95. struct file_system_type *type,
  96. const char *name, void *data);
  97. extern void mnt_set_expiry(struct vfsmount *mnt, struct list_head *expiry_list);
  98. extern void mark_mounts_for_expiry(struct list_head *mounts);
  99. extern dev_t name_to_dev_t(const char *name);
  100. extern unsigned int sysctl_mount_max;
  101. extern bool path_is_mountpoint(const struct path *path);
  102. extern void kern_unmount_array(struct vfsmount *mnt[], unsigned int num);
  103. #endif /* _LINUX_MOUNT_H */