* [PATCH v2 1/2] ovl: support [S|G]ETFLAGS and FS[S|G]ETXATTR ioctls for directories
@ 2020-09-29 7:28 Xiao Yang
2020-09-29 7:28 ` [PATCH v2 2/2] ovl: use generic vfs_ioc_setflags_prepare() helper Xiao Yang
0 siblings, 1 reply; 2+ messages in thread
From: Xiao Yang @ 2020-09-29 7:28 UTC (permalink / raw)
To: linux-unionfs; +Cc: miklos, amir73il, hch, darrick.wong, fstests, Xiao Yang
From: Amir Goldstein <amir73il@gmail.com>
[S|G]ETFLAGS and FS[S|G]ETXATTR ioctls are applicable to both files and
directories, so add ioctl operations to dir as well.
We teach ovl_real_fdget() to get the realfile of directories which use
a different type of file->private_data.
ifdef away compat ioctl implementation to conform to standard practice.
With this change, xfstest generic/079 which tests these ioctls on files
and directories passes.
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Xiao Yang <yangx.jy@cn.fujitsu.com>
Reviewed-by: Xiao Yang <yangx.jy@cn.fujitsu.com>
---
V1->v2:
1) Rename subject
2) Rebase on top of the following branch:
git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs.git overlayfs-next
fs/overlayfs/file.c | 16 +++++++++++++---
fs/overlayfs/overlayfs.h | 3 +++
fs/overlayfs/readdir.c | 33 ++++++++++++++++++++++++++++-----
3 files changed, 44 insertions(+), 8 deletions(-)
diff --git a/fs/overlayfs/file.c b/fs/overlayfs/file.c
index 3582c3ae819c..90b9aaebdf57 100644
--- a/fs/overlayfs/file.c
+++ b/fs/overlayfs/file.c
@@ -136,6 +136,13 @@ static int ovl_real_fdget_meta(const struct file *file, struct fd *real,
static int ovl_real_fdget(const struct file *file, struct fd *real)
{
+ if (d_is_dir(file_dentry(file))) {
+ real->flags = 0;
+ real->file = ovl_dir_real_file(file, false);
+
+ return PTR_ERR_OR_ZERO(real->file);
+ }
+
return ovl_real_fdget_meta(file, real, false);
}
@@ -648,7 +655,7 @@ static long ovl_ioctl_set_fsxflags(struct file *file, unsigned int cmd,
ovl_fsxflags_to_iflags(fa.fsx_xflags));
}
-static long ovl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+long ovl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
long ret;
@@ -673,8 +680,8 @@ static long ovl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
return ret;
}
-static long ovl_compat_ioctl(struct file *file, unsigned int cmd,
- unsigned long arg)
+#ifdef CONFIG_COMPAT
+long ovl_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
switch (cmd) {
case FS_IOC32_GETFLAGS:
@@ -691,6 +698,7 @@ static long ovl_compat_ioctl(struct file *file, unsigned int cmd,
return ovl_ioctl(file, cmd, arg);
}
+#endif
enum ovl_copyop {
OVL_COPY,
@@ -792,7 +800,9 @@ const struct file_operations ovl_file_operations = {
.fallocate = ovl_fallocate,
.fadvise = ovl_fadvise,
.unlocked_ioctl = ovl_ioctl,
+#ifdef CONFIG_COMPAT
.compat_ioctl = ovl_compat_ioctl,
+#endif
.splice_read = ovl_splice_read,
.splice_write = ovl_splice_write,
diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h
index 7bce2469fe55..f8880aa2ba0e 100644
--- a/fs/overlayfs/overlayfs.h
+++ b/fs/overlayfs/overlayfs.h
@@ -416,6 +416,7 @@ static inline int ovl_verify_upper(struct ovl_fs *ofs, struct dentry *index,
/* readdir.c */
extern const struct file_operations ovl_dir_operations;
+struct file *ovl_dir_real_file(const struct file *file, bool want_upper);
int ovl_check_empty_dir(struct dentry *dentry, struct list_head *list);
void ovl_cleanup_whiteouts(struct dentry *upper, struct list_head *list);
void ovl_cache_free(struct list_head *list);
@@ -503,6 +504,8 @@ struct dentry *ovl_create_temp(struct dentry *workdir, struct ovl_cattr *attr);
extern const struct file_operations ovl_file_operations;
int __init ovl_aio_request_cache_init(void);
void ovl_aio_request_cache_destroy(void);
+long ovl_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
+long ovl_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
/* copy_up.c */
int ovl_copy_up(struct dentry *dentry);
diff --git a/fs/overlayfs/readdir.c b/fs/overlayfs/readdir.c
index 596002054ac6..392efbbe9242 100644
--- a/fs/overlayfs/readdir.c
+++ b/fs/overlayfs/readdir.c
@@ -853,16 +853,22 @@ static struct file *ovl_dir_open_realfile(struct file *file,
return res;
}
-static int ovl_dir_fsync(struct file *file, loff_t start, loff_t end,
- int datasync)
+/*
+ * Like ovl_real_fdget(), returns upperfile if dir was copied up since open.
+ * Unlike ovl_real_fdget(), this caches upperfile in file->private_data.
+ *
+ * TODO: use same abstract type for file->private_data of dir and file so
+ * upperfile could also be cached for files as well.
+ */
+struct file *ovl_dir_real_file(const struct file *file, bool want_upper)
{
+
struct ovl_dir_file *od = file->private_data;
struct dentry *dentry = file->f_path.dentry;
struct file *realfile = od->realfile;
- /* Nothing to sync for lower */
if (!OVL_TYPE_UPPER(ovl_path_type(dentry)))
- return 0;
+ return want_upper ? NULL : realfile;
if (!ovl_should_sync(OVL_FS(dentry->d_sb)))
return 0;
@@ -884,7 +890,7 @@ static int ovl_dir_fsync(struct file *file, loff_t start, loff_t end,
if (!od->upperfile) {
if (IS_ERR(realfile)) {
inode_unlock(inode);
- return PTR_ERR(realfile);
+ return realfile;
}
smp_store_release(&od->upperfile, realfile);
} else {
@@ -897,6 +903,19 @@ static int ovl_dir_fsync(struct file *file, loff_t start, loff_t end,
}
}
+ return realfile;
+}
+
+static int ovl_dir_fsync(struct file *file, loff_t start, loff_t end,
+ int datasync)
+{
+ struct file *realfile = ovl_dir_real_file(file, true);
+ int err = PTR_ERR_OR_ZERO(realfile);
+
+ /* Nothing to sync for lower */
+ if (!realfile || err)
+ return err;
+
return vfs_fsync_range(realfile, start, end, datasync);
}
@@ -949,6 +968,10 @@ const struct file_operations ovl_dir_operations = {
.llseek = ovl_dir_llseek,
.fsync = ovl_dir_fsync,
.release = ovl_dir_release,
+ .unlocked_ioctl = ovl_ioctl,
+#ifdef CONFIG_COMPAT
+ .compat_ioctl = ovl_compat_ioctl,
+#endif
};
int ovl_check_empty_dir(struct dentry *dentry, struct list_head *list)
--
2.25.1
^ permalink raw reply related [flat|nested] 2+ messages in thread
* [PATCH v2 2/2] ovl: use generic vfs_ioc_setflags_prepare() helper
2020-09-29 7:28 [PATCH v2 1/2] ovl: support [S|G]ETFLAGS and FS[S|G]ETXATTR ioctls for directories Xiao Yang
@ 2020-09-29 7:28 ` Xiao Yang
0 siblings, 0 replies; 2+ messages in thread
From: Xiao Yang @ 2020-09-29 7:28 UTC (permalink / raw)
To: linux-unionfs; +Cc: miklos, amir73il, hch, darrick.wong, fstests, Xiao Yang
From: Amir Goldstein <amir73il@gmail.com>
Canonalize to ioctl FS_* flags instead of inode S_* flags.
Note that we do not call the helper vfs_ioc_fssetxattr_check()
for FS_IOC_FSSETXATTR ioctl. The reason is that underlying filesystem
will perform all the checks. We only need to perform the capability
check before overriding credentials.
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Xiao Yang <yangx.jy@cn.fujitsu.com>
Reviewed-by: Xiao Yang <yangx.jy@cn.fujitsu.com>
---
V1->v2:
1) Rebase on top of the following branch:
git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs.git overlayfs-nex
fs/overlayfs/file.c | 62 ++++++++++++++++++++++-----------------------
1 file changed, 30 insertions(+), 32 deletions(-)
diff --git a/fs/overlayfs/file.c b/fs/overlayfs/file.c
index 90b9aaebdf57..7f82c9fc9d9a 100644
--- a/fs/overlayfs/file.c
+++ b/fs/overlayfs/file.c
@@ -559,12 +559,28 @@ static long ovl_real_ioctl(struct file *file, unsigned int cmd,
return ret;
}
+static unsigned int ovl_iflags_to_fsflags(unsigned int iflags)
+{
+ unsigned int flags = 0;
+
+ if (iflags & S_SYNC)
+ flags |= FS_SYNC_FL;
+ if (iflags & S_APPEND)
+ flags |= FS_APPEND_FL;
+ if (iflags & S_IMMUTABLE)
+ flags |= FS_IMMUTABLE_FL;
+ if (iflags & S_NOATIME)
+ flags |= FS_NOATIME_FL;
+
+ return flags;
+}
+
static long ovl_ioctl_set_flags(struct file *file, unsigned int cmd,
- unsigned long arg, unsigned int iflags)
+ unsigned long arg, unsigned int flags)
{
long ret;
struct inode *inode = file_inode(file);
- unsigned int old_iflags;
+ unsigned int oldflags;
if (!inode_owner_or_capable(inode))
return -EACCES;
@@ -576,10 +592,9 @@ static long ovl_ioctl_set_flags(struct file *file, unsigned int cmd,
inode_lock(inode);
/* Check the capability before cred override */
- ret = -EPERM;
- old_iflags = READ_ONCE(inode->i_flags);
- if (((iflags ^ old_iflags) & (S_APPEND | S_IMMUTABLE)) &&
- !capable(CAP_LINUX_IMMUTABLE))
+ oldflags = ovl_iflags_to_fsflags(READ_ONCE(inode->i_flags));
+ ret = vfs_ioc_setflags_prepare(inode, oldflags, flags);
+ if (ret)
goto unlock;
ret = ovl_maybe_copy_up(file_dentry(file), O_WRONLY);
@@ -598,22 +613,6 @@ static long ovl_ioctl_set_flags(struct file *file, unsigned int cmd,
}
-static unsigned int ovl_fsflags_to_iflags(unsigned int flags)
-{
- unsigned int iflags = 0;
-
- if (flags & FS_SYNC_FL)
- iflags |= S_SYNC;
- if (flags & FS_APPEND_FL)
- iflags |= S_APPEND;
- if (flags & FS_IMMUTABLE_FL)
- iflags |= S_IMMUTABLE;
- if (flags & FS_NOATIME_FL)
- iflags |= S_NOATIME;
-
- return iflags;
-}
-
static long ovl_ioctl_set_fsflags(struct file *file, unsigned int cmd,
unsigned long arg)
{
@@ -622,24 +621,23 @@ static long ovl_ioctl_set_fsflags(struct file *file, unsigned int cmd,
if (get_user(flags, (int __user *) arg))
return -EFAULT;
- return ovl_ioctl_set_flags(file, cmd, arg,
- ovl_fsflags_to_iflags(flags));
+ return ovl_ioctl_set_flags(file, cmd, arg, flags);
}
-static unsigned int ovl_fsxflags_to_iflags(unsigned int xflags)
+static unsigned int ovl_fsxflags_to_fsflags(unsigned int xflags)
{
- unsigned int iflags = 0;
+ unsigned int flags = 0;
if (xflags & FS_XFLAG_SYNC)
- iflags |= S_SYNC;
+ flags |= FS_SYNC_FL;
if (xflags & FS_XFLAG_APPEND)
- iflags |= S_APPEND;
+ flags |= FS_APPEND_FL;
if (xflags & FS_XFLAG_IMMUTABLE)
- iflags |= S_IMMUTABLE;
+ flags |= FS_IMMUTABLE_FL;
if (xflags & FS_XFLAG_NOATIME)
- iflags |= S_NOATIME;
+ flags |= FS_NOATIME_FL;
- return iflags;
+ return flags;
}
static long ovl_ioctl_set_fsxflags(struct file *file, unsigned int cmd,
@@ -652,7 +650,7 @@ static long ovl_ioctl_set_fsxflags(struct file *file, unsigned int cmd,
return -EFAULT;
return ovl_ioctl_set_flags(file, cmd, arg,
- ovl_fsxflags_to_iflags(fa.fsx_xflags));
+ ovl_fsxflags_to_fsflags(fa.fsx_xflags));
}
long ovl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
--
2.25.1
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