Changes since last update:

- Support FS_IOC_GETFSLABEL ioctl;
 
  - Stop meaningless read-more policy on fragment extents;
 
  - Remove a duplicate check for ztailpacking inline.
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Merge tag 'erofs-for-6.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs

Pull erofs updates from Gao Xiang:

 - Support FS_IOC_GETFSLABEL ioctl

 - Stop meaningless read-more policy on fragment extents

 - Remove a duplicate check for ztailpacking inline

* tag 'erofs-for-6.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs:
  erofs: drop redundant sanity check for ztailpacking inline
  erofs: Add support for FS_IOC_GETFSLABEL
  erofs: avoid reading more for fragment maps

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,

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
 };

fs/erofs/inode.c

@@ -5,6 +5,7 @@
  * Copyright (C) 2021, Alibaba Cloud
  */
 #include "xattr.h"
+#include <linux/compat.h>
 #include <trace/events/erofs.h>
 
 static int erofs_fill_symlink(struct inode *inode, void *kaddr,
@@ -213,10 +214,7 @@ static int erofs_fill_inode(struct inode *inode)
 	switch (inode->i_mode & S_IFMT) {
 	case S_IFREG:
 		inode->i_op = &erofs_generic_iops;
-		if (erofs_inode_is_data_compressed(vi->datalayout))
-			inode->i_fop = &generic_ro_fops;
-		else
-			inode->i_fop = &erofs_file_fops;
+		inode->i_fop = &erofs_file_fops;
 		break;
 	case S_IFDIR:
 		inode->i_op = &erofs_dir_iops;
@@ -341,6 +339,40 @@ int erofs_getattr(struct mnt_idmap *idmap, const struct path *path,
 	return 0;
 }
 
+static int erofs_ioctl_get_volume_label(struct inode *inode, void __user *arg)
+{
+	struct erofs_sb_info *sbi = EROFS_I_SB(inode);
+	int ret;
+
+	if (!sbi->volume_name)
+		ret = clear_user(arg, 1);
+	else
+		ret = copy_to_user(arg, sbi->volume_name,
+				   strlen(sbi->volume_name));
+	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
+
 const struct inode_operations erofs_generic_iops = {
 	.getattr = erofs_getattr,
 	.listxattr = erofs_listxattr,

fs/erofs/internal.h

@@ -153,6 +153,7 @@ struct erofs_sb_info {
 	/* used for statfs, f_files - f_favail */
 	u64 inos;
 
+	char *volume_name;
 	u32 feature_compat;
 	u32 feature_incompat;
 
@@ -536,6 +537,10 @@ 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 */

fs/erofs/super.c

@@ -343,6 +343,13 @@ 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));
 
+	if (dsb->volume_name[0]) {
+		sbi->volume_name = kstrndup(dsb->volume_name,
+					    sizeof(dsb->volume_name), GFP_KERNEL);
+		if (!sbi->volume_name)
+			return -ENOMEM;
+	}
+
 	/* parse on-disk compression configurations */
 	ret = z_erofs_parse_cfgs(sb, dsb);
 	if (ret < 0)
@@ -822,6 +829,7 @@ static void erofs_sb_free(struct erofs_sb_info *sbi)
 	kfree(sbi->domain_id);
 	if (sbi->dif0.file)
 		fput(sbi->dif0.file);
+	kfree(sbi->volume_name);
 	kfree(sbi);
 }
 

fs/erofs/zdata.c

@@ -823,9 +823,6 @@ static int z_erofs_pcluster_begin(struct z_erofs_frontend *fe)
 			}
 			rcu_read_unlock();
 		}
-	} else if ((map->m_pa & ~PAGE_MASK) + map->m_plen > PAGE_SIZE) {
-		DBG_BUGON(1);
-		return -EFSCORRUPTED;
 	}
 
 	if (pcl) {
@@ -1835,7 +1832,7 @@ static void z_erofs_pcluster_readmore(struct z_erofs_frontend *f,
 		map->m_la = end;
 		err = z_erofs_map_blocks_iter(inode, map,
 					      EROFS_GET_BLOCKS_READMORE);
-		if (err)
+		if (err || !(map->m_flags & EROFS_MAP_ENCODED))
 			return;
 
 		/* expand ra for the trailing edge if readahead */
@@ -1847,7 +1844,7 @@ static void z_erofs_pcluster_readmore(struct z_erofs_frontend *f,
 		end = round_up(end, PAGE_SIZE);
 	} else {
 		end = round_up(map->m_la, PAGE_SIZE);
-		if (!map->m_llen)
+		if (!(map->m_flags & EROFS_MAP_ENCODED) || !map->m_llen)
 			return;
 	}
 

fs/erofs/zmap.c

@@ -462,8 +462,8 @@ static int z_erofs_map_blocks_fo(struct inode *inode,
 		map->m_pa = vi->z_fragmentoff;
 		map->m_plen = vi->z_idata_size;
 		if (erofs_blkoff(sb, map->m_pa) + map->m_plen > sb->s_blocksize) {
-			erofs_err(sb, "invalid tail-packing pclustersize %llu",
-				  map->m_plen);
+			erofs_err(sb, "ztailpacking inline data across blocks @ nid %llu",
+				  vi->nid);
 			err = -EFSCORRUPTED;
 			goto unmap_out;
 		}