From 0dca705f7cdf251059de077ee334d14c4c05507b Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Mon, 1 Jul 2019 13:26:29 -0700 Subject: [PATCH] f2fs: use generic checking function for FS_IOC_FSSETXATTR Make the f2fs implementation of FS_IOC_FSSETXATTR use the new VFS helper function vfs_ioc_fssetxattr_check(), and remove the project quota check since it's now done by the helper function. This is based on a patch from Darrick Wong, but reworked to apply after commit 360985573b55 ("f2fs: separate f2fs i_flags from fs_flags and ext4 i_flags"). Originally-from: Darrick J. Wong Signed-off-by: Eric Biggers Reviewed-by: Chao Yu Reviewed-by: Darrick J. Wong Signed-off-by: Jaegeuk Kim --- fs/f2fs/file.c | 45 +++++++++++---------------------- fs/inode.c | 62 ++++++++++++++++++++++++++++++++++++++++++++++ include/linux/fs.h | 9 +++++++ 3 files changed, 85 insertions(+), 31 deletions(-) diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c index 4d2665ec5be3..4cdb11eb2607 100644 --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -2862,52 +2862,32 @@ static inline u32 f2fs_xflags_to_iflags(u32 xflags) return iflags; } -static int f2fs_ioc_fsgetxattr(struct file *filp, unsigned long arg) +static void f2fs_fill_fsxattr(struct inode *inode, struct fsxattr *fa) { - struct inode *inode = file_inode(filp); struct f2fs_inode_info *fi = F2FS_I(inode); - struct fsxattr fa; - memset(&fa, 0, sizeof(struct fsxattr)); - fa.fsx_xflags = f2fs_iflags_to_xflags(fi->i_flags); + simple_fill_fsxattr(fa, f2fs_iflags_to_xflags(fi->i_flags)); if (f2fs_sb_has_project_quota(F2FS_I_SB(inode))) - fa.fsx_projid = (__u32)from_kprojid(&init_user_ns, - fi->i_projid); - - if (copy_to_user((struct fsxattr __user *)arg, &fa, sizeof(fa))) - return -EFAULT; - return 0; + fa->fsx_projid = from_kprojid(&init_user_ns, fi->i_projid); } -static int f2fs_ioctl_check_project(struct inode *inode, struct fsxattr *fa) +static int f2fs_ioc_fsgetxattr(struct file *filp, unsigned long arg) { - /* - * Project Quota ID state is only allowed to change from within the init - * namespace. Enforce that restriction only if we are trying to change - * the quota ID state. Everything else is allowed in user namespaces. - */ - if (current_user_ns() == &init_user_ns) - return 0; - - if (__kprojid_val(F2FS_I(inode)->i_projid) != fa->fsx_projid) - return -EINVAL; + struct inode *inode = file_inode(filp); + struct fsxattr fa; - if (F2FS_I(inode)->i_flags & F2FS_PROJINHERIT_FL) { - if (!(fa->fsx_xflags & FS_XFLAG_PROJINHERIT)) - return -EINVAL; - } else { - if (fa->fsx_xflags & FS_XFLAG_PROJINHERIT) - return -EINVAL; - } + f2fs_fill_fsxattr(inode, &fa); + if (copy_to_user((struct fsxattr __user *)arg, &fa, sizeof(fa))) + return -EFAULT; return 0; } static int f2fs_ioc_fssetxattr(struct file *filp, unsigned long arg) { struct inode *inode = file_inode(filp); - struct fsxattr fa; + struct fsxattr fa, old_fa; u32 iflags; int err; @@ -2930,9 +2910,12 @@ static int f2fs_ioc_fssetxattr(struct file *filp, unsigned long arg) return err; inode_lock(inode); - err = f2fs_ioctl_check_project(inode, &fa); + + f2fs_fill_fsxattr(inode, &old_fa); + err = vfs_ioc_fssetxattr_check(inode, &old_fa, &fa); if (err) goto out; + err = f2fs_setflags_common(inode, iflags, f2fs_xflags_to_iflags(F2FS_SUPPORTED_XFLAGS)); if (err) diff --git a/fs/inode.c b/fs/inode.c index beda394100ca..95fece639652 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -2149,3 +2149,65 @@ int vfs_ioc_setflags_prepare(struct inode *inode, unsigned int oldflags, return 0; } EXPORT_SYMBOL(vfs_ioc_setflags_prepare); + +/* + * Generic function to check FS_IOC_FSSETXATTR values and reject any invalid + * configurations. + * + * Note: the caller should be holding i_mutex, or else be sure that they have + * exclusive access to the inode structure. + */ +int vfs_ioc_fssetxattr_check(struct inode *inode, const struct fsxattr *old_fa, + struct fsxattr *fa) +{ + /* + * Can't modify an immutable/append-only file unless we have + * appropriate permission. + */ + if ((old_fa->fsx_xflags ^ fa->fsx_xflags) & + (FS_XFLAG_IMMUTABLE | FS_XFLAG_APPEND) && + !capable(CAP_LINUX_IMMUTABLE)) + return -EPERM; + + /* + * Project Quota ID state is only allowed to change from within the init + * namespace. Enforce that restriction only if we are trying to change + * the quota ID state. Everything else is allowed in user namespaces. + */ + if (current_user_ns() != &init_user_ns) { + if (old_fa->fsx_projid != fa->fsx_projid) + return -EINVAL; + if ((old_fa->fsx_xflags ^ fa->fsx_xflags) & + FS_XFLAG_PROJINHERIT) + return -EINVAL; + } + + /* Check extent size hints. */ + if ((fa->fsx_xflags & FS_XFLAG_EXTSIZE) && !S_ISREG(inode->i_mode)) + return -EINVAL; + + if ((fa->fsx_xflags & FS_XFLAG_EXTSZINHERIT) && + !S_ISDIR(inode->i_mode)) + return -EINVAL; + + if ((fa->fsx_xflags & FS_XFLAG_COWEXTSIZE) && + !S_ISREG(inode->i_mode) && !S_ISDIR(inode->i_mode)) + return -EINVAL; + + /* + * It is only valid to set the DAX flag on regular files and + * directories on filesystems. + */ + if ((fa->fsx_xflags & FS_XFLAG_DAX) && + !(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode))) + return -EINVAL; + + /* Extent size hints of zero turn off the flags. */ + if (fa->fsx_extsize == 0) + fa->fsx_xflags &= ~(FS_XFLAG_EXTSIZE | FS_XFLAG_EXTSZINHERIT); + if (fa->fsx_cowextsize == 0) + fa->fsx_xflags &= ~FS_XFLAG_COWEXTSIZE; + + return 0; +} +EXPORT_SYMBOL(vfs_ioc_fssetxattr_check); diff --git a/include/linux/fs.h b/include/linux/fs.h index 825a942d0e33..95fab032f24f 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -3397,4 +3397,13 @@ extern void inode_nohighmem(struct inode *inode); int vfs_ioc_setflags_prepare(struct inode *inode, unsigned int oldflags, unsigned int flags); +int vfs_ioc_fssetxattr_check(struct inode *inode, const struct fsxattr *old_fa, + struct fsxattr *fa); + +static inline void simple_fill_fsxattr(struct fsxattr *fa, __u32 xflags) +{ + memset(fa, 0, sizeof(*fa)); + fa->fsx_xflags = xflags; +} + #endif /* _LINUX_FS_H */