Before calling write f_ops, call file_start_write() instead
of sb_start_write().
This ensures freeze protection for both overlay and upper fs
when file is open from an overlayfs mount.
Replace {sb,file}_start_write() for {copy,clone}_file_range() and
for fallocate().
For dedup_file_range() there is no need for mnt_want_write_file().
File is already open for write, so we already have mnt_want_write()
and we only need file_start_write().
Signed-off-by: Amir Goldstein <amir73il@xxxxxxxxx>
---
fs/open.c | 4 ++--
fs/read_write.c | 12 ++++--------
include/linux/fs.h | 26 +++++++++++++-------------
3 files changed, 19 insertions(+), 23 deletions(-)
diff --git a/fs/open.c b/fs/open.c
index 9921f70..d3fe1a1 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -316,7 +316,7 @@ int vfs_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
if (!file->f_op->fallocate)
return -EOPNOTSUPP;
- sb_start_write(inode->i_sb);
+ file_start_write(file);
ret = file->f_op->fallocate(file, mode, offset, len);
/*
@@ -329,7 +329,7 @@ int vfs_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
if (ret == 0)
fsnotify_modify(file);
- sb_end_write(inode->i_sb);
+ file_end_write(file);
return ret;
}
EXPORT_SYMBOL_GPL(vfs_fallocate);
diff --git a/fs/read_write.c b/fs/read_write.c
index 5816d4c..1e42487 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -1538,7 +1538,7 @@ ssize_t vfs_copy_file_range(struct file *file_in, loff_t pos_in,
if (len == 0)
return 0;
- sb_start_write(inode_out->i_sb);
+ file_start_write(file_out);
/*
* Try cloning first, this is supported by more file systems, and
@@ -1574,7 +1574,7 @@ ssize_t vfs_copy_file_range(struct file *file_in, loff_t pos_in,
inc_syscr(current);
inc_syscw(current);
- sb_end_write(inode_out->i_sb);
+ file_end_write(file_out);
return ret;
}
@@ -1976,11 +1976,7 @@ int vfs_dedupe_file_range(struct file *file, struct file_dedupe_range *same)
}
dst = file_inode(dst_file);
- ret = mnt_want_write_file(dst_file);
- if (ret) {
- info->status = ret;
- goto next_loop;
- }
+ file_start_write(dst_file);
dst_off = info->dest_offset;
ret = clone_verify_area(dst_file, dst_off, len, true);
@@ -2013,7 +2009,7 @@ int vfs_dedupe_file_range(struct file *file, struct file_dedupe_range *same)
}
next_file:
- mnt_drop_write_file(dst_file);
+ file_end_write(dst_file);
next_loop:
fdput(dst_fd);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 71811be..8a4dbc6 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1741,19 +1741,6 @@ extern int vfs_dedupe_file_range_compare(struct inode *src, loff_t srcoff,
extern int vfs_dedupe_file_range(struct file *file,
struct file_dedupe_range *same);
-static inline int do_clone_file_range(struct file *file_in, loff_t pos_in,
- struct file *file_out, loff_t pos_out,
- u64 len)
-{
- int ret;
-
- sb_start_write(file_inode(file_out)->i_sb);
- ret = vfs_clone_file_range(file_in, pos_in, file_out, pos_out, len);
- sb_end_write(file_inode(file_out)->i_sb);
-
- return ret;
-}
-
struct super_operations {
struct inode *(*alloc_inode)(struct super_block *sb);
void (*destroy_inode)(struct inode *);
@@ -2579,6 +2566,19 @@ static inline void file_end_write(struct file *file)
__sb_end_write(locks_inode(file)->i_sb, SB_FREEZE_WRITE);
}
+static inline int do_clone_file_range(struct file *file_in, loff_t pos_in,
+ struct file *file_out, loff_t pos_out,
+ u64 len)
+{
+ int ret;
+
+ file_start_write(file_out);
+ ret = vfs_clone_file_range(file_in, pos_in, file_out, pos_out, len);
+ file_end_write(file_out);
+
+ return ret;
+}
+
/*
* get_write_access() gets write permission for a file.
* put_write_access() releases this write permission.
--
2.7.4
--
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