X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=include%2Flinux%2Fiso_fs.h;h=dd53b6cd217354318905d5630f1f2436d169540c;hb=9bf4aaab3e101692164d49b7ca357651eb691cb6;hp=223f161da018509c4b2369fd267cc4ee9236a086;hpb=5273a3df6485dc2ad6aa7ddd441b9a21970f003b;p=linux-2.6.git diff --git a/include/linux/iso_fs.h b/include/linux/iso_fs.h index 223f161da..dd53b6cd2 100644 --- a/include/linux/iso_fs.h +++ b/include/linux/iso_fs.h @@ -190,28 +190,28 @@ static inline int isonum_712(char *p) { return *(s8 *)p; } -static inline int isonum_721(char *p) +static inline unsigned int isonum_721(char *p) { return le16_to_cpu(get_unaligned((u16 *)p)); } -static inline int isonum_722(char *p) +static inline unsigned int isonum_722(char *p) { return be16_to_cpu(get_unaligned((u16 *)p)); } -static inline int isonum_723(char *p) +static inline unsigned int isonum_723(char *p) { /* Ignore bigendian datum due to broken mastering programs */ return le16_to_cpu(get_unaligned((u16 *)p)); } -static inline int isonum_731(char *p) +static inline unsigned int isonum_731(char *p) { return le32_to_cpu(get_unaligned((u32 *)p)); } -static inline int isonum_732(char *p) +static inline unsigned int isonum_732(char *p) { return be32_to_cpu(get_unaligned((u32 *)p)); } -static inline int isonum_733(char *p) +static inline unsigned int isonum_733(char *p) { /* Ignore bigendian datum due to broken mastering programs */ return le32_to_cpu(get_unaligned((u32 *)p)); @@ -231,9 +231,69 @@ extern struct dentry *isofs_lookup(struct inode *, struct dentry *, struct namei extern struct buffer_head *isofs_bread(struct inode *, sector_t); extern int isofs_get_blocks(struct inode *, sector_t, struct buffer_head **, unsigned long); +extern struct inode *isofs_iget(struct super_block *sb, + unsigned long block, + unsigned long offset); + +/* Because the inode number is no longer relevant to finding the + * underlying meta-data for an inode, we are free to choose a more + * convenient 32-bit number as the inode number. The inode numbering + * scheme was recommended by Sergey Vlasov and Eric Lammerts. */ +static inline unsigned long isofs_get_ino(unsigned long block, + unsigned long offset, + unsigned long bufbits) +{ + return (block << (bufbits - 5)) | (offset >> 5); +} + +/* Every directory can have many redundant directory entries scattered + * throughout the directory tree. First there is the directory entry + * with the name of the directory stored in the parent directory. + * Then, there is the "." directory entry stored in the directory + * itself. Finally, there are possibly many ".." directory entries + * stored in all the subdirectories. + * + * In order for the NFS get_parent() method to work and for the + * general consistency of the dcache, we need to make sure the + * "i_iget5_block" and "i_iget5_offset" all point to exactly one of + * the many redundant entries for each directory. We normalize the + * block and offset by always making them point to the "." directory. + * + * Notice that we do not use the entry for the directory with the name + * that is located in the parent directory. Even though choosing this + * first directory is more natural, it is much easier to find the "." + * entry in the NFS get_parent() method because it is implicitly + * encoded in the "extent + ext_attr_length" fields of _all_ the + * redundant entries for the directory. Thus, it can always be + * reached regardless of which directory entry you have in hand. + * + * This works because the "." entry is simply the first directory + * record when you start reading the file that holds all the directory + * records, and this file starts at "extent + ext_attr_length" blocks. + * Because the "." entry is always the first entry listed in the + * directories file, the normalized "offset" value is always 0. + * + * You should pass the directory entry in "de". On return, "block" + * and "offset" will hold normalized values. Only directories are + * affected making it safe to call even for non-directory file + * types. */ +static inline void +isofs_normalize_block_and_offset(struct iso_directory_record* de, + unsigned long *block, + unsigned long *offset) +{ + /* Only directories are normalized. */ + if (de->flags[0] & 2) { + *offset = 0; + *block = (unsigned long)isonum_733(de->extent) + + (unsigned long)isonum_711(de->ext_attr_length); + } +} + extern struct inode_operations isofs_dir_inode_operations; extern struct file_operations isofs_dir_operations; extern struct address_space_operations isofs_symlink_aops; +extern struct export_operations isofs_export_ops; /* The following macros are used to check for memory leaks. */ #ifdef LEAK_CHECK