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1/* SPDX-License-Identifier: GPL-2.0 */2#include <linux/fs.h>3#include <linux/qnx4_fs.h>4 5#define QNX4_DEBUG 06 7#if QNX4_DEBUG8#define QNX4DEBUG(X) printk X9#else10#define QNX4DEBUG(X) (void) 011#endif12 13struct qnx4_sb_info {14 unsigned int Version; /* may be useful */15 struct qnx4_inode_entry *BitMap; /* useful */16};17 18struct qnx4_inode_info {19 struct qnx4_inode_entry raw;20 loff_t mmu_private;21 struct inode vfs_inode;22};23 24extern struct inode *qnx4_iget(struct super_block *, unsigned long);25extern struct dentry *qnx4_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags);26extern unsigned long qnx4_count_free_blocks(struct super_block *sb);27extern unsigned long qnx4_block_map(struct inode *inode, long iblock);28 29extern const struct inode_operations qnx4_dir_inode_operations;30extern const struct file_operations qnx4_dir_operations;31extern int qnx4_is_free(struct super_block *sb, long block);32 33static inline struct qnx4_sb_info *qnx4_sb(struct super_block *sb)34{35 return sb->s_fs_info;36}37 38static inline struct qnx4_inode_info *qnx4_i(struct inode *inode)39{40 return container_of(inode, struct qnx4_inode_info, vfs_inode);41}42 43static inline struct qnx4_inode_entry *qnx4_raw_inode(struct inode *inode)44{45 return &qnx4_i(inode)->raw;46}47 48/*49 * A qnx4 directory entry is an inode entry or link info50 * depending on the status field in the last byte. The51 * first byte is where the name start either way, and a52 * zero means it's empty.53 *54 * Also, due to a bug in gcc, we don't want to use the55 * real (differently sized) name arrays in the inode and56 * link entries, but always the 'de_name[]' one in the57 * fake struct entry.58 *59 * See60 *61 * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99578#c662 *63 * for details, but basically gcc will take the size of the64 * 'name' array from one of the used union entries randomly.65 *66 * This use of 'de_name[]' (48 bytes) avoids the false positive67 * warnings that would happen if gcc decides to use 'inode.di_name'68 * (16 bytes) even when the pointer and size were to come from69 * 'link.dl_name' (48 bytes).70 *71 * In all cases the actual name pointer itself is the same, it's72 * only the gcc internal 'what is the size of this field' logic73 * that can get confused.74 */75union qnx4_directory_entry {76 struct {77 const char de_name[48];78 u8 de_pad[15];79 u8 de_status;80 };81 struct qnx4_inode_entry inode;82 struct qnx4_link_info link;83};84 85static inline const char *get_entry_fname(union qnx4_directory_entry *de,86 int *size)87{88 /* Make sure the status byte is in the same place for all structs. */89 BUILD_BUG_ON(offsetof(struct qnx4_inode_entry, di_status) !=90 offsetof(struct qnx4_link_info, dl_status));91 BUILD_BUG_ON(offsetof(struct qnx4_inode_entry, di_status) !=92 offsetof(union qnx4_directory_entry, de_status));93 94 if (!de->de_name[0])95 return NULL;96 if (!(de->de_status & (QNX4_FILE_USED|QNX4_FILE_LINK)))97 return NULL;98 if (!(de->de_status & QNX4_FILE_LINK))99 *size = sizeof(de->inode.di_fname);100 else101 *size = sizeof(de->link.dl_fname);102 103 *size = strnlen(de->de_name, *size);104 105 return de->de_name;106}107