Enable setting flag FS_CASEFOLD_FL for tmpfs directories, when tmpfs is mounted with casefold support. A special check is need for this flag, since it can't be set for non-empty directories. Signed-off-by: André Almeida <andrealmeid@xxxxxxxxxx> Reviewed-by: Gabriel Krisman Bertazi <krisman@xxxxxxx> --- Changes from v2: - Fixed bug when adding a non-casefold flag in a non-empty dir --- include/linux/shmem_fs.h | 6 ++--- mm/shmem.c | 70 +++++++++++++++++++++++++++++++++++++++++++----- 2 files changed, 67 insertions(+), 9 deletions(-) diff --git a/include/linux/shmem_fs.h b/include/linux/shmem_fs.h index 515a9a6a3c6f82c55952d821887514217a6a00d1..018da28c01e7d71b8fb00bfb23c000248c8a83f4 100644 --- a/include/linux/shmem_fs.h +++ b/include/linux/shmem_fs.h @@ -42,10 +42,10 @@ struct shmem_inode_info { struct inode vfs_inode; }; -#define SHMEM_FL_USER_VISIBLE FS_FL_USER_VISIBLE +#define SHMEM_FL_USER_VISIBLE (FS_FL_USER_VISIBLE | FS_CASEFOLD_FL) #define SHMEM_FL_USER_MODIFIABLE \ - (FS_IMMUTABLE_FL | FS_APPEND_FL | FS_NODUMP_FL | FS_NOATIME_FL) -#define SHMEM_FL_INHERITED (FS_NODUMP_FL | FS_NOATIME_FL) + (FS_IMMUTABLE_FL | FS_APPEND_FL | FS_NODUMP_FL | FS_NOATIME_FL | FS_CASEFOLD_FL) +#define SHMEM_FL_INHERITED (FS_NODUMP_FL | FS_NOATIME_FL | FS_CASEFOLD_FL) struct shmem_quota_limits { qsize_t usrquota_bhardlimit; /* Default user quota block hard limit */ diff --git a/mm/shmem.c b/mm/shmem.c index ea4eff41eef35c9c253092f39402db142baa741b..8d206e492e7d51dad4bfe1b36426e0064b612dad 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -2760,13 +2760,62 @@ static int shmem_file_open(struct inode *inode, struct file *file) #ifdef CONFIG_TMPFS_XATTR static int shmem_initxattrs(struct inode *, const struct xattr *, void *); +#if IS_ENABLED(CONFIG_UNICODE) +/* + * shmem_inode_casefold_flags - Deal with casefold file attribute flag + * + * The casefold file attribute needs some special checks. I can just be added to + * an empty dir, and can't be removed from a non-empty dir. + */ +static int shmem_inode_casefold_flags(struct inode *inode, unsigned int fsflags, + struct dentry *dentry, unsigned int *i_flags) +{ + unsigned int old = inode->i_flags; + struct super_block *sb = inode->i_sb; + + if (fsflags & FS_CASEFOLD_FL) { + if (!(old & S_CASEFOLD)) { + if (!sb->s_encoding) + return -EOPNOTSUPP; + + if (!S_ISDIR(inode->i_mode)) + return -ENOTDIR; + + if (dentry && !simple_empty(dentry)) + return -ENOTEMPTY; + } + + *i_flags = *i_flags | S_CASEFOLD; + } else if (old & S_CASEFOLD) { + if (dentry && !simple_empty(dentry)) + return -ENOTEMPTY; + } + + return 0; +} +#else +static int shmem_inode_casefold_flags(struct inode *inode, unsigned int fsflags, + struct dentry *dentry, unsigned int *i_flags) +{ + if (fsflags & FS_CASEFOLD_FL) + return -EOPNOTSUPP; + + return 0; +} +#endif + /* * chattr's fsflags are unrelated to extended attributes, * but tmpfs has chosen to enable them under the same config option. */ -static void shmem_set_inode_flags(struct inode *inode, unsigned int fsflags) +static int shmem_set_inode_flags(struct inode *inode, unsigned int fsflags, struct dentry *dentry) { unsigned int i_flags = 0; + int ret; + + ret = shmem_inode_casefold_flags(inode, fsflags, dentry, &i_flags); + if (ret) + return ret; if (fsflags & FS_NOATIME_FL) i_flags |= S_NOATIME; @@ -2777,10 +2826,12 @@ static void shmem_set_inode_flags(struct inode *inode, unsigned int fsflags) /* * But FS_NODUMP_FL does not require any action in i_flags. */ - inode_set_flags(inode, i_flags, S_NOATIME | S_APPEND | S_IMMUTABLE); + inode_set_flags(inode, i_flags, S_NOATIME | S_APPEND | S_IMMUTABLE | S_CASEFOLD); + + return 0; } #else -static void shmem_set_inode_flags(struct inode *inode, unsigned int fsflags) +static void shmem_set_inode_flags(struct inode *inode, unsigned int fsflags, struct dentry *dentry) { } #define shmem_initxattrs NULL @@ -2827,7 +2878,7 @@ static struct inode *__shmem_get_inode(struct mnt_idmap *idmap, info->fsflags = (dir == NULL) ? 0 : SHMEM_I(dir)->fsflags & SHMEM_FL_INHERITED; if (info->fsflags) - shmem_set_inode_flags(inode, info->fsflags); + shmem_set_inode_flags(inode, info->fsflags, NULL); INIT_LIST_HEAD(&info->shrinklist); INIT_LIST_HEAD(&info->swaplist); simple_xattrs_init(&info->xattrs); @@ -3934,16 +3985,23 @@ static int shmem_fileattr_set(struct mnt_idmap *idmap, { struct inode *inode = d_inode(dentry); struct shmem_inode_info *info = SHMEM_I(inode); + int ret, flags; if (fileattr_has_fsx(fa)) return -EOPNOTSUPP; if (fa->flags & ~SHMEM_FL_USER_MODIFIABLE) return -EOPNOTSUPP; - info->fsflags = (info->fsflags & ~SHMEM_FL_USER_MODIFIABLE) | + flags = (info->fsflags & ~SHMEM_FL_USER_MODIFIABLE) | (fa->flags & SHMEM_FL_USER_MODIFIABLE); - shmem_set_inode_flags(inode, info->fsflags); + ret = shmem_set_inode_flags(inode, flags, dentry); + + if (ret) + return ret; + + info->fsflags = flags; + inode_set_ctime_current(inode); inode_inc_iversion(inode); return 0; -- 2.47.0