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/* SPDX-License-Identifier: GPL-2.0 */
#include <linux/fs.h>
#include <linux/qnx4_fs.h>
#define QNX4_DEBUG 0
#if QNX4_DEBUG
#define QNX4DEBUG(X) printk X
#else
#define QNX4DEBUG(X) (void) 0
#endif
struct qnx4_sb_info {
unsigned int Version; /* may be useful */
struct qnx4_inode_entry *BitMap; /* useful */
};
struct qnx4_inode_info {
struct qnx4_inode_entry raw;
loff_t mmu_private;
struct inode vfs_inode;
};
extern struct inode *qnx4_iget(struct super_block *, unsigned long);
extern struct dentry *qnx4_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags);
extern unsigned long qnx4_count_free_blocks(struct super_block *sb);
extern unsigned long qnx4_block_map(struct inode *inode, long iblock);
extern const struct inode_operations qnx4_dir_inode_operations;
extern const struct file_operations qnx4_dir_operations;
extern int qnx4_is_free(struct super_block *sb, long block);
static inline struct qnx4_sb_info *qnx4_sb(struct super_block *sb)
{
return sb->s_fs_info;
}
static inline struct qnx4_inode_info *qnx4_i(struct inode *inode)
{
return container_of(inode, struct qnx4_inode_info, vfs_inode);
}
static inline struct qnx4_inode_entry *qnx4_raw_inode(struct inode *inode)
{
return &qnx4_i(inode)->raw;
}
/*
* A qnx4 directory entry is an inode entry or link info
* depending on the status field in the last byte. The
* first byte is where the name start either way, and a
* zero means it's empty.
*
* Also, due to a bug in gcc, we don't want to use the
* real (differently sized) name arrays in the inode and
* link entries, but always the 'de_name[]' one in the
* fake struct entry.
*
* See
*
* https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99578#c6
*
* for details, but basically gcc will take the size of the
* 'name' array from one of the used union entries randomly.
*
* This use of 'de_name[]' (48 bytes) avoids the false positive
* warnings that would happen if gcc decides to use 'inode.di_name'
* (16 bytes) even when the pointer and size were to come from
* 'link.dl_name' (48 bytes).
*
* In all cases the actual name pointer itself is the same, it's
* only the gcc internal 'what is the size of this field' logic
* that can get confused.
*/
union qnx4_directory_entry {
struct {
const char de_name[48];
u8 de_pad[15];
u8 de_status;
};
struct qnx4_inode_entry inode;
struct qnx4_link_info link;
};
static inline const char *get_entry_fname(union qnx4_directory_entry *de,
int *size)
{
/* Make sure the status byte is in the same place for all structs. */
BUILD_BUG_ON(offsetof(struct qnx4_inode_entry, di_status) !=
offsetof(struct qnx4_link_info, dl_status));
BUILD_BUG_ON(offsetof(struct qnx4_inode_entry, di_status) !=
offsetof(union qnx4_directory_entry, de_status));
if (!de->de_name[0])
return NULL;
if (!(de->de_status & (QNX4_FILE_USED|QNX4_FILE_LINK)))
return NULL;
if (!(de->de_status & QNX4_FILE_LINK))
*size = sizeof(de->inode.di_fname);
else
*size = sizeof(de->link.dl_fname);
*size = strnlen(de->de_name, *size);
return de->de_name;
}
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