From: Bo Liu (OpenAnolis) <liub...@inspur.com>
Add support for reading to the erofs volume label from the
FS_IOC_GETFSLABEL ioctls.
Signed-off-by: Bo Liu (OpenAnolis) <liub...@inspur.com>
---
fs/erofs/Makefile | 2 +-
fs/erofs/data.c | 4 ++++
fs/erofs/dir.c | 4 ++++
fs/erofs/inode.c | 2 +-
fs/erofs/internal.h | 10 ++++++++++
fs/erofs/ioctl.c | 47 +++++++++++++++++++++++++++++++++++++++++++++
fs/erofs/super.c | 2 ++
fs/erofs/zdata.c | 11 +++++++++++
8 files changed, 80 insertions(+), 2 deletions(-)
create mode 100644 fs/erofs/ioctl.c
diff --git a/fs/erofs/Makefile b/fs/erofs/Makefile
index 549abc424763..5be6cc4acc1c 100644
--- a/fs/erofs/Makefile
+++ b/fs/erofs/Makefile
@@ -1,7 +1,7 @@
# SPDX-License-Identifier: GPL-2.0-only
obj-$(CONFIG_EROFS_FS) += erofs.o
-erofs-objs := super.o inode.o data.o namei.o dir.o sysfs.o
+erofs-objs := super.o inode.o data.o namei.o dir.o sysfs.o ioctl.o
erofs-$(CONFIG_EROFS_FS_XATTR) += xattr.o
erofs-$(CONFIG_EROFS_FS_ZIP) += decompressor.o zmap.o zdata.o zutil.o
erofs-$(CONFIG_EROFS_FS_ZIP_LZMA) += decompressor_lzma.o
diff --git a/fs/erofs/data.c b/fs/erofs/data.c
index 3b1ba571c728..8ca29962a3dd 100644
--- a/fs/erofs/data.c
+++ b/fs/erofs/data.c
@@ -475,6 +475,10 @@ static loff_t erofs_file_llseek(struct file *file, loff_t
offset, int whence)
const struct file_operations erofs_file_fops = {
.llseek = erofs_file_llseek,
.read_iter = erofs_file_read_iter,
+ .unlocked_ioctl = erofs_ioctl,
+#ifdef CONFIG_COMPAT
+ .compat_ioctl = erofs_compat_ioctl,
+#endif
.mmap_prepare = erofs_file_mmap_prepare,
.get_unmapped_area = thp_get_unmapped_area,
.splice_read = filemap_splice_read,
diff --git a/fs/erofs/dir.c b/fs/erofs/dir.c
index debf469ad6bd..32b4f5aa60c9 100644
--- a/fs/erofs/dir.c
+++ b/fs/erofs/dir.c
@@ -123,4 +123,8 @@ const struct file_operations erofs_dir_fops = {
.llseek = generic_file_llseek,
.read = generic_read_dir,
.iterate_shared = erofs_readdir,
+ .unlocked_ioctl = erofs_ioctl,
+#ifdef CONFIG_COMPAT
+ .compat_ioctl = erofs_compat_ioctl,
+#endif
};
diff --git a/fs/erofs/inode.c b/fs/erofs/inode.c
index 9a2f59721522..9248143e26df 100644
--- a/fs/erofs/inode.c
+++ b/fs/erofs/inode.c
@@ -214,7 +214,7 @@ static int erofs_fill_inode(struct inode *inode)
case S_IFREG:
inode->i_op = &erofs_generic_iops;
if (erofs_inode_is_data_compressed(vi->datalayout))
- inode->i_fop = &generic_ro_fops;
+ inode->i_fop = &z_erofs_file_fops;
else
inode->i_fop = &erofs_file_fops;
break;
diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h
index 4ccc5f0ee8df..2f874b920c8b 100644
--- a/fs/erofs/internal.h
+++ b/fs/erofs/internal.h
@@ -32,6 +32,8 @@ __printf(2, 3) void _erofs_printk(struct super_block *sb,
const char *fmt, ...);
#define DBG_BUGON(x) ((void)(x))
#endif /* !CONFIG_EROFS_FS_DEBUG */
+#define EROFS_VOLUME_LABEL_LEN 16
+
/* EROFS_SUPER_MAGIC_V1 to represent the whole file system */
#define EROFS_SUPER_MAGIC EROFS_SUPER_MAGIC_V1
@@ -166,6 +168,9 @@ struct erofs_sb_info {
struct erofs_domain *domain;
char *fsid;
char *domain_id;
+
+ /* volume name */
+ u8 volume_label[EROFS_VOLUME_LABEL_LEN];
};
#define EROFS_SB(sb) ((struct erofs_sb_info *)(sb)->s_fs_info)
@@ -404,6 +409,7 @@ extern const struct inode_operations erofs_dir_iops;
extern const struct file_operations erofs_file_fops;
extern const struct file_operations erofs_dir_fops;
+extern const struct file_operations z_erofs_file_fops;
extern const struct iomap_ops z_erofs_iomap_report_ops;
@@ -535,6 +541,10 @@ static inline struct bio *erofs_fscache_bio_alloc(struct
erofs_map_dev *mdev) {
static inline void erofs_fscache_submit_bio(struct bio *bio) {}
#endif
+long erofs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg);
+long erofs_compat_ioctl(struct file *filp, unsigned int cmd,
+ unsigned long arg);
+
#define EFSCORRUPTED EUCLEAN /* Filesystem is corrupted */
#endif /* __EROFS_INTERNAL_H */
diff --git a/fs/erofs/ioctl.c b/fs/erofs/ioctl.c
new file mode 100644
index 000000000000..10bfd593225f
--- /dev/null
+++ b/fs/erofs/ioctl.c
@@ -0,0 +1,47 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#include <linux/fs.h>
+#include <linux/compat.h>
+#include <linux/file.h>
+
+#include "erofs_fs.h"
+#include "internal.h"
+
+static int erofs_ioctl_get_volume_label(struct inode *inode, void __user *arg)
+{
+ struct erofs_sb_info *sbi = EROFS_I_SB(inode);
+ size_t len;
+ int ret;
+ char label[EROFS_VOLUME_LABEL_LEN];
+
+ memcpy(label, sbi->volume_label, EROFS_VOLUME_LABEL_LEN);
+
+ len = strnlen(label, EROFS_VOLUME_LABEL_LEN);
+ if (len == EROFS_VOLUME_LABEL_LEN)
+ erofs_err(inode->i_sb, "label is too long, return the first %zu
bytes",
+ --len);
+
+ ret = copy_to_user(arg, label, len);
+
+ return ret ? -EFAULT : 0;
+}
+
+long erofs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
+{
+ struct inode *inode = file_inode(filp);
+ void __user *argp = (void __user *)arg;
+
+ switch (cmd) {
+ case FS_IOC_GETFSLABEL:
+ return erofs_ioctl_get_volume_label(inode, argp);
+ default:
+ return -ENOTTY;
+ }
+}
+
+#ifdef CONFIG_COMPAT
+long erofs_compat_ioctl(struct file *filp, unsigned int cmd,
+ unsigned long arg)
+{
+ return erofs_ioctl(filp, cmd, (unsigned long)compat_ptr(arg));
+}
+#endif
diff --git a/fs/erofs/super.c b/fs/erofs/super.c
index 1b529ace4db0..e6ad6cf4ba82 100644
--- a/fs/erofs/super.c
+++ b/fs/erofs/super.c
@@ -343,6 +343,8 @@ static int erofs_read_superblock(struct super_block *sb)
sbi->fixed_nsec = le32_to_cpu(dsb->fixed_nsec);
super_set_uuid(sb, (void *)dsb->uuid, sizeof(dsb->uuid));
+ memcpy(sbi->volume_label, dsb->volume_name, EROFS_VOLUME_LABEL_LEN);
+
/* parse on-disk compression configurations */
ret = z_erofs_parse_cfgs(sb, dsb);
if (ret < 0)
diff --git a/fs/erofs/zdata.c b/fs/erofs/zdata.c
index 2d73297003d2..b612bf7b2f08 100644
--- a/fs/erofs/zdata.c
+++ b/fs/erofs/zdata.c
@@ -1931,3 +1931,14 @@ const struct address_space_operations z_erofs_aops = {
.read_folio = z_erofs_read_folio,
.readahead = z_erofs_readahead,
};
+
+const struct file_operations z_erofs_file_fops = {
+ .llseek = generic_file_llseek,
+ .read_iter = generic_file_read_iter,
+ .unlocked_ioctl = erofs_ioctl,
+#ifdef CONFIG_COMPAT
+ .compat_ioctl = erofs_compat_ioctl,
+#endif
+ .mmap = generic_file_readonly_mmap,
+ .splice_read = filemap_splice_read,
+};
--
2.31.1
