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Diffstat (limited to 'fs/remap_range.c')
-rw-r--r--fs/remap_range.c52
1 files changed, 25 insertions, 27 deletions
diff --git a/fs/remap_range.c b/fs/remap_range.c
index 87ae4f0dc3..de07f978ce 100644
--- a/fs/remap_range.c
+++ b/fs/remap_range.c
@@ -102,7 +102,9 @@ static int generic_remap_checks(struct file *file_in, loff_t pos_in,
static int remap_verify_area(struct file *file, loff_t pos, loff_t len,
bool write)
{
+ int mask = write ? MAY_WRITE : MAY_READ;
loff_t tmp;
+ int ret;
if (unlikely(pos < 0 || len < 0))
return -EINVAL;
@@ -110,7 +112,11 @@ static int remap_verify_area(struct file *file, loff_t pos, loff_t len,
if (unlikely(check_add_overflow(pos, len, &tmp)))
return -EINVAL;
- return security_file_permission(file, write ? MAY_WRITE : MAY_READ);
+ ret = security_file_permission(file, mask);
+ if (ret)
+ return ret;
+
+ return fsnotify_file_area_perm(file, mask, &pos, len);
}
/*
@@ -367,9 +373,9 @@ int generic_remap_file_range_prep(struct file *file_in, loff_t pos_in,
}
EXPORT_SYMBOL(generic_remap_file_range_prep);
-loff_t do_clone_file_range(struct file *file_in, loff_t pos_in,
- struct file *file_out, loff_t pos_out,
- loff_t len, unsigned int remap_flags)
+loff_t vfs_clone_file_range(struct file *file_in, loff_t pos_in,
+ struct file *file_out, loff_t pos_out,
+ loff_t len, unsigned int remap_flags)
{
loff_t ret;
@@ -393,8 +399,10 @@ loff_t do_clone_file_range(struct file *file_in, loff_t pos_in,
if (ret)
return ret;
+ file_start_write(file_out);
ret = file_in->f_op->remap_file_range(file_in, pos_in,
file_out, pos_out, len, remap_flags);
+ file_end_write(file_out);
if (ret < 0)
return ret;
@@ -402,25 +410,10 @@ loff_t do_clone_file_range(struct file *file_in, loff_t pos_in,
fsnotify_modify(file_out);
return ret;
}
-EXPORT_SYMBOL(do_clone_file_range);
-
-loff_t vfs_clone_file_range(struct file *file_in, loff_t pos_in,
- struct file *file_out, loff_t pos_out,
- loff_t len, unsigned int remap_flags)
-{
- loff_t ret;
-
- file_start_write(file_out);
- ret = do_clone_file_range(file_in, pos_in, file_out, pos_out, len,
- remap_flags);
- file_end_write(file_out);
-
- return ret;
-}
EXPORT_SYMBOL(vfs_clone_file_range);
/* Check whether we are allowed to dedupe the destination file */
-static bool allow_file_dedupe(struct file *file)
+static bool may_dedupe_file(struct file *file)
{
struct mnt_idmap *idmap = file_mnt_idmap(file);
struct inode *inode = file_inode(file);
@@ -445,24 +438,29 @@ loff_t vfs_dedupe_file_range_one(struct file *src_file, loff_t src_pos,
WARN_ON_ONCE(remap_flags & ~(REMAP_FILE_DEDUP |
REMAP_FILE_CAN_SHORTEN));
- ret = mnt_want_write_file(dst_file);
- if (ret)
- return ret;
-
/*
* This is redundant if called from vfs_dedupe_file_range(), but other
* callers need it and it's not performance sesitive...
*/
ret = remap_verify_area(src_file, src_pos, len, false);
if (ret)
- goto out_drop_write;
+ return ret;
ret = remap_verify_area(dst_file, dst_pos, len, true);
if (ret)
- goto out_drop_write;
+ return ret;
+
+ /*
+ * This needs to be called after remap_verify_area() because of
+ * sb_start_write() and before may_dedupe_file() because the mount's
+ * MAY_WRITE need to be checked with mnt_get_write_access_file() held.
+ */
+ ret = mnt_want_write_file(dst_file);
+ if (ret)
+ return ret;
ret = -EPERM;
- if (!allow_file_dedupe(dst_file))
+ if (!may_dedupe_file(dst_file))
goto out_drop_write;
ret = -EXDEV;