Stop using struct fd to return a real file from ovl_real_fdget_path(),
because we no longer return a temporary file object and the callers
always get a borrowed file reference.
Rename the helper to ovl_real_file_path(), return a borrowed reference
of the real file that is referenced from the overlayfs file or an error.
Signed-off-by: Amir Goldstein <amir73il@xxxxxxxxx>
---
fs/overlayfs/file.c | 70 +++++++++++++++++++++++++--------------------
1 file changed, 39 insertions(+), 31 deletions(-)
diff --git a/fs/overlayfs/file.c b/fs/overlayfs/file.c
index 42f9bbdd65b4..ead805e9f2d6 100644
--- a/fs/overlayfs/file.c
+++ b/fs/overlayfs/file.c
@@ -97,16 +97,14 @@ static bool ovl_is_real_file(const struct file *realfile,
return file_inode(realfile) == d_inode(realpath->dentry);
}
-static int ovl_real_fdget_path(const struct file *file, struct fd *real,
- struct path *realpath)
+static struct file *ovl_real_file_path(const struct file *file,
+ struct path *realpath)
{
struct file *realfile = file->private_data;
struct file *upperfile = backing_file_private(realfile);
- real->word = 0;
-
if (WARN_ON_ONCE(!realpath->dentry))
- return -EIO;
+ return ERR_PTR(-EIO);
/*
* Usually, if we operated on a stashed upperfile once, all following
@@ -129,11 +127,11 @@ static int ovl_real_fdget_path(const struct file *file, struct fd *real,
/* Either stashed realfile or upperfile must match realinode */
if (WARN_ON_ONCE(upperfile))
- return -EIO;
+ return ERR_PTR(-EIO);
upperfile = ovl_open_realfile(file, realpath);
if (IS_ERR(upperfile))
- return PTR_ERR(upperfile);
+ return upperfile;
old = cmpxchg_release(backing_file_private_ptr(realfile), NULL,
upperfile);
@@ -144,21 +142,24 @@ static int ovl_real_fdget_path(const struct file *file, struct fd *real,
/* Stashed upperfile that won the race must match realinode */
if (WARN_ON_ONCE(!ovl_is_real_file(upperfile, realpath)))
- return -EIO;
+ return ERR_PTR(-EIO);
realfile = upperfile;
}
checkflags:
/* Did the flags change since open? */
- if (unlikely((file->f_flags ^ realfile->f_flags) & ~OVL_OPEN_FLAGS))
- return ovl_change_flags(realfile, file->f_flags);
+ if (unlikely((file->f_flags ^ realfile->f_flags) & ~OVL_OPEN_FLAGS)) {
+ int err = ovl_change_flags(realfile, file->f_flags);
- real->word = (unsigned long)realfile;
- return 0;
+ if (err)
+ return ERR_PTR(err);
+ }
+
+ return realfile;
}
-static int ovl_real_fdget(const struct file *file, struct fd *real)
+static struct file *ovl_real_file(const struct file *file)
{
struct dentry *dentry = file_dentry(file);
struct path realpath;
@@ -166,23 +167,33 @@ static int ovl_real_fdget(const struct file *file, struct fd *real)
if (d_is_dir(dentry)) {
struct file *f = ovl_dir_real_file(file, false);
- if (IS_ERR(f))
- return PTR_ERR(f);
- real->word = (unsigned long)f;
- return 0;
+
+ if (WARN_ON_ONCE(!f))
+ return ERR_PTR(-EIO);
+ return f;
}
/* lazy lookup and verify of lowerdata */
err = ovl_verify_lowerdata(dentry);
if (err)
- return err;
+ return ERR_PTR(err);
ovl_path_realdata(dentry, &realpath);
- return ovl_real_fdget_path(file, real, &realpath);
+ return ovl_real_file_path(file, &realpath);
+}
+
+static int ovl_real_fdget(const struct file *file, struct fd *real)
+{
+ struct file *f = ovl_real_file(file);
+
+ if (IS_ERR(f))
+ return PTR_ERR(f);
+ real->word = (unsigned long)f;
+ return 0;
}
-static int ovl_upper_fdget(const struct file *file, struct fd *real, bool data)
+static struct file *ovl_upper_file(const struct file *file, bool data)
{
struct dentry *dentry = file_dentry(file);
struct path realpath;
@@ -193,12 +204,11 @@ static int ovl_upper_fdget(const struct file *file, struct fd *real, bool data)
else
type = ovl_path_real(dentry, &realpath);
- real->word = 0;
/* Not interested in lower nor in upper meta if data was requested */
if (!OVL_TYPE_UPPER(type) || (data && OVL_TYPE_MERGE(type)))
- return 0;
+ return NULL;
- return ovl_real_fdget_path(file, real, &realpath);
+ return ovl_real_file_path(file, &realpath);
}
static int ovl_open(struct inode *inode, struct file *file)
@@ -455,7 +465,7 @@ static ssize_t ovl_splice_write(struct pipe_inode_info *pipe, struct file *out,
static int ovl_fsync(struct file *file, loff_t start, loff_t end, int datasync)
{
- struct fd real;
+ struct file *realfile;
const struct cred *old_cred;
int ret;
@@ -463,19 +473,17 @@ static int ovl_fsync(struct file *file, loff_t start, loff_t end, int datasync)
if (ret <= 0)
return ret;
- ret = ovl_upper_fdget(file, &real, datasync);
- if (ret || fd_empty(real))
- return ret;
+ realfile = ovl_upper_file(file, datasync);
+ if (IS_ERR_OR_NULL(realfile))
+ return PTR_ERR(realfile);
/* Don't sync lower file for fear of receiving EROFS error */
- if (file_inode(fd_file(real)) == ovl_inode_upper(file_inode(file))) {
+ if (file_inode(realfile) == ovl_inode_upper(file_inode(file))) {
old_cred = ovl_override_creds(file_inode(file)->i_sb);
- ret = vfs_fsync_range(fd_file(real), start, end, datasync);
+ ret = vfs_fsync_range(realfile, start, end, datasync);
revert_creds(old_cred);
}
- fdput(real);
-
return ret;
}
--
2.34.1
