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-rw-r--r--include/linux/fs.h100
1 files changed, 94 insertions, 6 deletions
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 562f2623c9c9..0e50f0316e0c 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -642,7 +642,7 @@ struct inode {
loff_t i_size;
struct timespec64 i_atime;
struct timespec64 i_mtime;
- struct timespec64 i_ctime;
+ struct timespec64 __i_ctime; /* use inode_*_ctime accessors! */
spinlock_t i_lock; /* i_blocks, i_bytes, maybe i_size */
unsigned short i_bytes;
u8 i_blkbits;
@@ -1474,7 +1474,79 @@ static inline bool fsuidgid_has_mapping(struct super_block *sb,
kgid_has_mapping(fs_userns, kgid);
}
-extern struct timespec64 current_time(struct inode *inode);
+struct timespec64 current_mgtime(struct inode *inode);
+struct timespec64 current_time(struct inode *inode);
+struct timespec64 inode_set_ctime_current(struct inode *inode);
+
+/*
+ * Multigrain timestamps
+ *
+ * Conditionally use fine-grained ctime and mtime timestamps when there
+ * are users actively observing them via getattr. The primary use-case
+ * for this is NFS clients that use the ctime to distinguish between
+ * different states of the file, and that are often fooled by multiple
+ * operations that occur in the same coarse-grained timer tick.
+ *
+ * The kernel always keeps normalized struct timespec64 values in the ctime,
+ * which means that only the first 30 bits of the value are used. Use the
+ * 31st bit of the ctime's tv_nsec field as a flag to indicate that the value
+ * has been queried since it was last updated.
+ */
+#define I_CTIME_QUERIED (1L<<30)
+
+/**
+ * inode_get_ctime - fetch the current ctime from the inode
+ * @inode: inode from which to fetch ctime
+ *
+ * Grab the current ctime tv_nsec field from the inode, mask off the
+ * I_CTIME_QUERIED flag and return it. This is mostly intended for use by
+ * internal consumers of the ctime that aren't concerned with ensuring a
+ * fine-grained update on the next change (e.g. when preparing to store
+ * the value in the backing store for later retrieval).
+ *
+ * This is safe to call regardless of whether the underlying filesystem
+ * is using multigrain timestamps.
+ */
+static inline struct timespec64 inode_get_ctime(const struct inode *inode)
+{
+ struct timespec64 ctime;
+
+ ctime.tv_sec = inode->__i_ctime.tv_sec;
+ ctime.tv_nsec = inode->__i_ctime.tv_nsec & ~I_CTIME_QUERIED;
+
+ return ctime;
+}
+
+/**
+ * inode_set_ctime_to_ts - set the ctime in the inode
+ * @inode: inode in which to set the ctime
+ * @ts: value to set in the ctime field
+ *
+ * Set the ctime in @inode to @ts
+ */
+static inline struct timespec64 inode_set_ctime_to_ts(struct inode *inode,
+ struct timespec64 ts)
+{
+ inode->__i_ctime = ts;
+ return ts;
+}
+
+/**
+ * inode_set_ctime - set the ctime in the inode
+ * @inode: inode in which to set the ctime
+ * @sec: tv_sec value to set
+ * @nsec: tv_nsec value to set
+ *
+ * Set the ctime in @inode to { @sec, @nsec }
+ */
+static inline struct timespec64 inode_set_ctime(struct inode *inode,
+ time64_t sec, long nsec)
+{
+ struct timespec64 ts = { .tv_sec = sec,
+ .tv_nsec = nsec };
+
+ return inode_set_ctime_to_ts(inode, ts);
+}
/*
* Snapshotting support.
@@ -1850,7 +1922,7 @@ struct inode_operations {
ssize_t (*listxattr) (struct dentry *, char *, size_t);
int (*fiemap)(struct inode *, struct fiemap_extent_info *, u64 start,
u64 len);
- int (*update_time)(struct inode *, struct timespec64 *, int);
+ int (*update_time)(struct inode *, int);
int (*atomic_open)(struct inode *, struct dentry *,
struct file *, unsigned open_flag,
umode_t create_mode);
@@ -2200,7 +2272,7 @@ enum file_time_flags {
extern bool atime_needs_update(const struct path *, struct inode *);
extern void touch_atime(const struct path *);
-int inode_update_time(struct inode *inode, struct timespec64 *time, int flags);
+int inode_update_time(struct inode *inode, int flags);
static inline void file_accessed(struct file *file)
{
@@ -2222,6 +2294,7 @@ struct file_system_type {
#define FS_USERNS_MOUNT 8 /* Can be mounted by userns root */
#define FS_DISALLOW_NOTIFY_PERM 16 /* Disable fanotify permission events */
#define FS_ALLOW_IDMAP 32 /* FS has been updated to handle vfs idmappings. */
+#define FS_MGTIME 64 /* FS uses multigrain timestamps */
#define FS_RENAME_DOES_D_MOVE 32768 /* FS will handle d_move() during rename() internally. */
int (*init_fs_context)(struct fs_context *);
const struct fs_parameter_spec *parameters;
@@ -2245,6 +2318,17 @@ struct file_system_type {
#define MODULE_ALIAS_FS(NAME) MODULE_ALIAS("fs-" NAME)
+/**
+ * is_mgtime: is this inode using multigrain timestamps
+ * @inode: inode to test for multigrain timestamps
+ *
+ * Return true if the inode uses multigrain timestamps, false otherwise.
+ */
+static inline bool is_mgtime(const struct inode *inode)
+{
+ return inode->i_sb->s_type->fs_flags & FS_MGTIME;
+}
+
extern struct dentry *mount_bdev(struct file_system_type *fs_type,
int flags, const char *dev_name, void *data,
int (*fill_super)(struct super_block *, void *, int));
@@ -2306,7 +2390,8 @@ extern int current_umask(void);
extern void ihold(struct inode * inode);
extern void iput(struct inode *);
-extern int generic_update_time(struct inode *, struct timespec64 *, int);
+int inode_update_timestamps(struct inode *inode, int flags);
+int generic_update_time(struct inode *, int);
/* /sys/fs */
extern struct kobject *fs_kobj;
@@ -2880,7 +2965,8 @@ extern void page_put_link(void *);
extern int page_symlink(struct inode *inode, const char *symname, int len);
extern const struct inode_operations page_symlink_inode_operations;
extern void kfree_link(void *);
-void generic_fillattr(struct mnt_idmap *, struct inode *, struct kstat *);
+void fill_mg_cmtime(struct kstat *stat, u32 request_mask, struct inode *inode);
+void generic_fillattr(struct mnt_idmap *, u32, struct inode *, struct kstat *);
void generic_fill_statx_attr(struct inode *inode, struct kstat *stat);
extern int vfs_getattr_nosec(const struct path *, struct kstat *, u32, unsigned int);
extern int vfs_getattr(const struct path *, struct kstat *, u32, unsigned int);
@@ -2940,6 +3026,8 @@ extern int simple_open(struct inode *inode, struct file *file);
extern int simple_link(struct dentry *, struct inode *, struct dentry *);
extern int simple_unlink(struct inode *, struct dentry *);
extern int simple_rmdir(struct inode *, struct dentry *);
+void simple_rename_timestamp(struct inode *old_dir, struct dentry *old_dentry,
+ struct inode *new_dir, struct dentry *new_dentry);
extern int simple_rename_exchange(struct inode *old_dir, struct dentry *old_dentry,
struct inode *new_dir, struct dentry *new_dentry);
extern int simple_rename(struct mnt_idmap *, struct inode *,