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-rw-r--r--include/linux/backing-file.h42
-rw-r--r--include/linux/fs.h71
-rw-r--r--include/linux/fsnotify.h50
-rw-r--r--include/linux/splice.h51
4 files changed, 169 insertions, 45 deletions
diff --git a/include/linux/backing-file.h b/include/linux/backing-file.h
new file mode 100644
index 000000000000..3f1fe1774f1b
--- /dev/null
+++ b/include/linux/backing-file.h
@@ -0,0 +1,42 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Common helpers for stackable filesystems and backing files.
+ *
+ * Copyright (C) 2023 CTERA Networks.
+ */
+
+#ifndef _LINUX_BACKING_FILE_H
+#define _LINUX_BACKING_FILE_H
+
+#include <linux/file.h>
+#include <linux/uio.h>
+#include <linux/fs.h>
+
+struct backing_file_ctx {
+ const struct cred *cred;
+ struct file *user_file;
+ void (*accessed)(struct file *);
+ void (*end_write)(struct file *);
+};
+
+struct file *backing_file_open(const struct path *user_path, int flags,
+ const struct path *real_path,
+ const struct cred *cred);
+ssize_t backing_file_read_iter(struct file *file, struct iov_iter *iter,
+ struct kiocb *iocb, int flags,
+ struct backing_file_ctx *ctx);
+ssize_t backing_file_write_iter(struct file *file, struct iov_iter *iter,
+ struct kiocb *iocb, int flags,
+ struct backing_file_ctx *ctx);
+ssize_t backing_file_splice_read(struct file *in, loff_t *ppos,
+ struct pipe_inode_info *pipe, size_t len,
+ unsigned int flags,
+ struct backing_file_ctx *ctx);
+ssize_t backing_file_splice_write(struct pipe_inode_info *pipe,
+ struct file *out, loff_t *ppos, size_t len,
+ unsigned int flags,
+ struct backing_file_ctx *ctx);
+int backing_file_mmap(struct file *file, struct vm_area_struct *vma,
+ struct backing_file_ctx *ctx);
+
+#endif /* _LINUX_BACKING_FILE_H */
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 7e7399bd8bc5..cdbf43a8ea88 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1648,9 +1648,70 @@ static inline bool __sb_start_write_trylock(struct super_block *sb, int level)
#define __sb_writers_release(sb, lev) \
percpu_rwsem_release(&(sb)->s_writers.rw_sem[(lev)-1], 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 lockdep_is_held_type(sb->s_writers.rw_sem + SB_FREEZE_WRITE - 1, 1);
+ 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;
+}
+
+/**
+ * file_write_started - check if SB_FREEZE_WRITE is held
+ * @file: the file we write to
+ *
+ * May be false positive with !CONFIG_LOCKDEP/LOCK_STATE_UNKNOWN.
+ * May be false positive with !S_ISREG, because file_start_write() has
+ * no effect on !S_ISREG.
+ */
+static inline bool file_write_started(const struct file *file)
+{
+ if (!S_ISREG(file_inode(file)->i_mode))
+ return true;
+ return sb_write_started(file_inode(file)->i_sb);
+}
+
+/**
+ * file_write_not_started - check if SB_FREEZE_WRITE is not held
+ * @file: the file we write to
+ *
+ * May be false positive with !CONFIG_LOCKDEP/LOCK_STATE_UNKNOWN.
+ * May be false positive with !S_ISREG, because file_start_write() has
+ * no effect on !S_ISREG.
+ */
+static inline bool file_write_not_started(const struct file *file)
+{
+ if (!S_ISREG(file_inode(file)->i_mode))
+ return true;
+ return sb_write_not_started(file_inode(file)->i_sb);
}
/**
@@ -2032,9 +2093,6 @@ extern ssize_t vfs_read(struct file *, char __user *, size_t, loff_t *);
extern ssize_t vfs_write(struct file *, const char __user *, size_t, loff_t *);
extern ssize_t vfs_copy_file_range(struct file *, loff_t , struct file *,
loff_t, size_t, unsigned int);
-extern ssize_t generic_copy_file_range(struct file *file_in, loff_t pos_in,
- struct file *file_out, loff_t pos_out,
- size_t len, unsigned int flags);
int __generic_remap_file_range_prep(struct file *file_in, loff_t pos_in,
struct file *file_out, loff_t pos_out,
loff_t *len, unsigned int remap_flags,
@@ -2535,9 +2593,6 @@ struct file *dentry_open(const struct path *path, int flags,
const struct cred *creds);
struct file *dentry_create(const struct path *path, int flags, umode_t mode,
const struct cred *cred);
-struct file *backing_file_open(const struct path *user_path, int flags,
- const struct path *real_path,
- const struct cred *cred);
struct path *backing_file_user_path(struct file *f);
/*
@@ -3017,8 +3072,6 @@ ssize_t copy_splice_read(struct file *in, loff_t *ppos,
size_t len, unsigned int flags);
extern ssize_t iter_file_splice_write(struct pipe_inode_info *,
struct file *, loff_t *, size_t, unsigned int);
-extern long do_splice_direct(struct file *in, loff_t *ppos, struct file *out,
- loff_t *opos, size_t len, unsigned int flags);
extern void
diff --git a/include/linux/fsnotify.h b/include/linux/fsnotify.h
index bcb6609b54b3..11e6434b8e71 100644
--- a/include/linux/fsnotify.h
+++ b/include/linux/fsnotify.h
@@ -100,29 +100,49 @@ static inline int fsnotify_file(struct file *file, __u32 mask)
return fsnotify_parent(path->dentry, mask, path, FSNOTIFY_EVENT_PATH);
}
-/* Simple call site for access decisions */
-static inline int fsnotify_perm(struct file *file, int mask)
+/*
+ * fsnotify_file_area_perm - permission hook before access to file range
+ */
+static inline int fsnotify_file_area_perm(struct file *file, int perm_mask,
+ const loff_t *ppos, size_t count)
{
- int ret;
- __u32 fsnotify_mask = 0;
+ __u32 fsnotify_mask = FS_ACCESS_PERM;
+
+ /*
+ * filesystem may be modified in the context of permission events
+ * (e.g. by HSM filling a file on access), so sb freeze protection
+ * must not be held.
+ */
+ lockdep_assert_once(file_write_not_started(file));
- if (!(mask & (MAY_READ | MAY_OPEN)))
+ if (!(perm_mask & MAY_READ))
return 0;
- if (mask & MAY_OPEN) {
- fsnotify_mask = FS_OPEN_PERM;
+ return fsnotify_file(file, fsnotify_mask);
+}
+
+/*
+ * fsnotify_file_perm - permission hook before file access
+ */
+static inline int fsnotify_file_perm(struct file *file, int perm_mask)
+{
+ return fsnotify_file_area_perm(file, perm_mask, NULL, 0);
+}
- if (file->f_flags & __FMODE_EXEC) {
- ret = fsnotify_file(file, FS_OPEN_EXEC_PERM);
+/*
+ * fsnotify_open_perm - permission hook before file open
+ */
+static inline int fsnotify_open_perm(struct file *file)
+{
+ int ret;
- if (ret)
- return ret;
- }
- } else if (mask & MAY_READ) {
- fsnotify_mask = FS_ACCESS_PERM;
+ if (file->f_flags & __FMODE_EXEC) {
+ ret = fsnotify_file(file, FS_OPEN_EXEC_PERM);
+ if (ret)
+ return ret;
}
- return fsnotify_file(file, fsnotify_mask);
+ return fsnotify_file(file, FS_OPEN_PERM);
}
/*
diff --git a/include/linux/splice.h b/include/linux/splice.h
index 6c461573434d..9dec4861d09f 100644
--- a/include/linux/splice.h
+++ b/include/linux/splice.h
@@ -68,28 +68,37 @@ typedef int (splice_actor)(struct pipe_inode_info *, struct pipe_buffer *,
typedef int (splice_direct_actor)(struct pipe_inode_info *,
struct splice_desc *);
-extern ssize_t splice_from_pipe(struct pipe_inode_info *, struct file *,
- loff_t *, size_t, unsigned int,
- splice_actor *);
-extern ssize_t __splice_from_pipe(struct pipe_inode_info *,
- struct splice_desc *, splice_actor *);
-extern ssize_t splice_to_pipe(struct pipe_inode_info *,
- struct splice_pipe_desc *);
-extern ssize_t add_to_pipe(struct pipe_inode_info *,
- struct pipe_buffer *);
-long vfs_splice_read(struct file *in, loff_t *ppos,
- struct pipe_inode_info *pipe, size_t len,
- unsigned int flags);
-extern ssize_t splice_direct_to_actor(struct file *, struct splice_desc *,
- splice_direct_actor *);
-extern long do_splice(struct file *in, loff_t *off_in,
- struct file *out, loff_t *off_out,
- size_t len, unsigned int flags);
+ssize_t splice_from_pipe(struct pipe_inode_info *pipe, struct file *out,
+ loff_t *ppos, size_t len, unsigned int flags,
+ splice_actor *actor);
+ssize_t __splice_from_pipe(struct pipe_inode_info *pipe,
+ struct splice_desc *sd, splice_actor *actor);
+ssize_t splice_to_pipe(struct pipe_inode_info *pipe,
+ struct splice_pipe_desc *spd);
+ssize_t add_to_pipe(struct pipe_inode_info *pipe, struct pipe_buffer *buf);
+ssize_t vfs_splice_read(struct file *in, loff_t *ppos,
+ struct pipe_inode_info *pipe, size_t len,
+ unsigned int flags);
+ssize_t splice_direct_to_actor(struct file *file, struct splice_desc *sd,
+ splice_direct_actor *actor);
+ssize_t do_splice(struct file *in, loff_t *off_in, struct file *out,
+ loff_t *off_out, size_t len, unsigned int flags);
+ssize_t do_splice_direct(struct file *in, loff_t *ppos, struct file *out,
+ loff_t *opos, size_t len, unsigned int flags);
+ssize_t splice_file_range(struct file *in, loff_t *ppos, struct file *out,
+ loff_t *opos, size_t len);
-extern long do_tee(struct file *in, struct file *out, size_t len,
- unsigned int flags);
-extern ssize_t splice_to_socket(struct pipe_inode_info *pipe, struct file *out,
- loff_t *ppos, size_t len, unsigned int flags);
+static inline long splice_copy_file_range(struct file *in, loff_t pos_in,
+ struct file *out, loff_t pos_out,
+ size_t len)
+{
+ return splice_file_range(in, &pos_in, out, &pos_out, len);
+}
+
+ssize_t do_tee(struct file *in, struct file *out, size_t len,
+ unsigned int flags);
+ssize_t splice_to_socket(struct pipe_inode_info *pipe, struct file *out,
+ loff_t *ppos, size_t len, unsigned int flags);
/*
* for dynamic pipe sizing
generated by cgit v1.2.3 (git 2.39.0) at 2025-12-28 18:20:24 +0300