X-Git-Url: https://wimlib.net/git/?p=wimlib;a=blobdiff_plain;f=src%2Flookup_table.h;h=4458cc7ef1a146c1c59d9e100f710a84a5288ccb;hp=6deb86fc531f7a74842b6adf6c1ca4e3a03c6798;hb=5cdd60306facd14cc9dcc24471386451294ca73c;hpb=6f7956a06fcf92a304fae93e393e8eaee34e92d5 diff --git a/src/lookup_table.h b/src/lookup_table.h index 6deb86fc..4458cc7e 100644 --- a/src/lookup_table.h +++ b/src/lookup_table.h @@ -2,174 +2,421 @@ #define _WIMLIB_LOOKUP_TABLE_H #include "wimlib_internal.h" #include "dentry.h" +#include "sha1.h" #include /* Size of each lookup table entry in the WIM file. */ #define WIM_LOOKUP_TABLE_ENTRY_DISK_SIZE 50 +#define LOOKUP_FLAG_ADS_OK 0x00000001 +#define LOOKUP_FLAG_DIRECTORY_OK 0x00000002 + +/* Not yet used */ +//#define LOOKUP_FLAG_FOLLOW_SYMLINKS 0x00000004 + /* A lookup table that is used to translate the hash codes of dentries into the * offsets and sizes of uncompressed or compressed file resources. It is * implemented as a hash table. */ struct lookup_table { - struct lookup_table_entry **array; + struct hlist_head *array; u64 num_entries; u64 capacity; }; -/* An entry in the lookup table in the WIM file. */ +struct wimlib_fd; + +#ifdef WITH_NTFS_3G +struct ntfs_location { + char *path_utf8; + char *stream_name_utf16; + u16 stream_name_utf16_num_chars; + struct _ntfs_volume **ntfs_vol_p; + bool is_reparse_point; +}; +#endif + +/* An enumerated type that identifies where the stream corresponding to this + * lookup table entry is actually located. + * + * If we open a WIM and read its lookup table, the location is set to + * RESOURCE_IN_WIM since all the streams will initially be located in the WIM. + * However, to deal with problems such as image capture and image mount, we + * allow the actual location of the stream to be somewhere else, such as an + * external file. + */ +enum resource_location { + /* The lookup table entry does not correspond to a stream (this state + * should exist only temporarily) */ + RESOURCE_NONEXISTENT = 0, + + /* The stream resource is located in a WIM file. The WIMStruct for the + * WIM file will be pointed to by the @wim member. */ + RESOURCE_IN_WIM, + + /* The stream resource is located in an external file. The name of the + * file will be provided by @file_on_disk member. In addition, if + * @file_on_disk_fp is not NULL, it will be an open FILE * to the file. + * */ + RESOURCE_IN_FILE_ON_DISK, + + /* The stream resource is located in an external file in the staging + * directory for a read-write mount. */ + RESOURCE_IN_STAGING_FILE, + + /* The stream resource is directly attached in an in-memory buffer + * pointed to by @attached_buffer. */ + RESOURCE_IN_ATTACHED_BUFFER, + + /* The stream resource is located in an NTFS volume. It is identified + * by volume, filename, data stream name, and by whether it is a reparse + * point or not. @ntfs_loc points to a structure containing this + * information. */ + RESOURCE_IN_NTFS_VOLUME, +}; + +/* + * An entry in the lookup table in the WIM file. + * + * It is used to find data streams for files in the WIM. + * + * Metadata resources and reparse point data buffers will also have lookup table + * entries associated with the data. + * + * The lookup_table_entry for a given dentry or alternate stream entry in the + * WIM is found using the SHA1 message digest field. + */ struct lookup_table_entry { - /* The next struct lookup_table_entry in the hash bucket. NULL if this is the - * last one. */ - struct lookup_table_entry *next; + /* List of lookup table entries in this hash bucket */ + struct hlist_node hash_list; - /* @resource_entry is read from the lookup table in the WIM - * file; it says where to find the file resource in the WIM - * file, and whether it is compressed or not. */ + /* Location and size of the stream in the WIM, whether it is compressed + * or not, and whether it's a metadata resource or not. This is an + * on-disk field. */ struct resource_entry resource_entry; - /* Currently ignored; set to 1 in new lookup table entries. */ + /* Specifies which part of the split WIM the resource is located in. + * This is on on-disk field. + * + * In stand-alone WIMs, this must be 1. + * + * In split WIMs, every split WIM part has its own lookup table, and in + * read_lookup_table() it's currently expected that the part number of + * each lookup table entry in a split WIM part's lookup table is the + * same as the part number of that split WIM part. So this makes this + * field redundant since we store a pointer to the corresponding + * WIMStruct in the lookup table entry anyway. + */ u16 part_number; - /* Number of times this lookup table entry is referenced by dentries. */ + /* See enum resource_location above */ + u16 resource_location; + + /* (On-disk field) + * Number of times this lookup table entry is referenced by dentries. + * Unfortunately, this field is not always set correctly in Microsoft's + * WIMs, so we have no choice but to fix it if more references to the + * lookup table entry are found than stated here. */ u32 refcnt; union { - /* SHA1 hash of the file resource pointed to by this lookup - * table entry */ - u8 hash[WIM_HASH_SIZE]; - - /* First 4 or 8 bytes of the SHA1 hash, used for inserting the - * entry into the hash table. Since the SHA1 hashes can be - * considered random, we don't really need the full 20 byte hash - * just to insert the entry in a hash table. */ + /* (On-disk field) SHA1 message digest of the stream referenced + * by this lookup table entry */ + u8 hash[SHA1_HASH_SIZE]; + + /* First 4 or 8 bytes of the SHA1 message digest, used for + * inserting the entry into the hash table. Since the SHA1 + * message digest can be considered random, we don't really need + * the full 20 byte hash just to insert the entry in a hash + * table. */ size_t hash_short; }; - /* If @file_on_disk != NULL, the file resource indicated by this lookup - * table entry is not in the WIM file, but rather a file on disk; this - * occurs for files that are added to the WIM. In that case, - * file_on_disk is the name of the file in the outside filesystem. - * It will not be compressed, and its size will be given by - * resource_entry.size and resource_entry.original_size. */ + #ifdef WITH_FUSE + u16 num_opened_fds; + #endif + + /* Pointers to somewhere where the stream is actually located. See the + * comments for the @resource_location field above. */ union { + WIMStruct *wim; char *file_on_disk; char *staging_file_name; - struct lookup_table_entry *next_lte_in_swm; + u8 *attached_buffer; + #ifdef WITH_NTFS_3G + struct ntfs_location *ntfs_loc; + #endif }; - union { - struct { /* Used for wimlib_export. */ + /* @file_on_disk_fp and @attr are both used to cache file/stream + * handles so we don't have re-open them on every read */ + + /* Valid iff resource_location == RESOURCE_IN_FILE_ON_DISK */ + FILE *file_on_disk_fp; + #ifdef WITH_NTFS_3G + /* Valid iff resource_location == RESOURCE_IN_NTFS_VOLUME */ + struct _ntfs_attr *attr; + #endif + + /* Pointer to inode that contains the opened file descriptors to + * this stream (valid iff resource_location == + * RESOURCE_IN_STAGING_FILE) */ + struct inode *lte_inode; + }; + + /* When a WIM file is written, out_refcnt starts at 0 and is incremented + * whenever the file resource pointed to by this lookup table entry + * needs to be written. The file resource only need to be written when + * out_refcnt is nonzero, since otherwise it is not referenced by any + * dentries. */ + u32 out_refcnt; - /* If (other_wim_fp != NULL), the file resource indicated - * by this lookup table entry is in a different WIM - * file, and other_wim_fp is the FILE* for it. */ - FILE *other_wim_fp; + u32 real_refcnt; - /* Compression type used in other WIM. */ - int other_wim_ctype; - }; + union { + /* When a WIM file is written, @output_resource_entry is filled + * in with the resource entry for the output WIM. This will not + * necessarily be the same as the @resource_entry since: - The + * stream may have a different offset in the new WIM - The + * stream may have a different compressed size in the new WIM if + * the compression type changed + */ + struct resource_entry output_resource_entry; + + struct list_head msg_list; + struct list_head dentry_list; + }; - struct { /* Used for read-write mounts. */ + union { + /* This field is used for the special hardlink or symlink image + * extraction mode. In these mode, all identical files are linked + * together, and @extracted_file will be set to the filename of the + * first extracted file containing this stream. */ + struct { + char *extracted_file; + bool extracted; + }; + /* List of lookup table entries that correspond to streams that have + * been extracted to the staging directory when modifying a read-write + * mounted WIM. */ + struct list_head staging_list; + }; +}; - /* Offset of the stream file_on_disk_fd. */ - off_t staging_offset; +static inline u64 wim_resource_size(const struct lookup_table_entry *lte) +{ + return lte->resource_entry.original_size; +} +static inline u64 wim_resource_chunks(const struct lookup_table_entry *lte) +{ + return (wim_resource_size(lte) + WIM_CHUNK_SIZE - 1) / WIM_CHUNK_SIZE; +} - /* If file_on_disk_fd, if it is not -1, is the file - * descriptor, opened for reading, for file_on_disk. */ - int staging_fd; +static inline u64 +wim_resource_compressed_size(const struct lookup_table_entry *lte) +{ + return lte->resource_entry.size; +} - /* Number of times the file has been opened. - * file_on_disk_fd can be closed when num_times_opened - * is decremented to 0. */ - int staging_num_times_opened; - }; - }; +/* + * XXX Probably should store the compression type directly in the lookup table + * entry + */ +static inline int +wim_resource_compression_type(const struct lookup_table_entry *lte) +{ + if (!(lte->resource_entry.flags & WIM_RESHDR_FLAG_COMPRESSED) + || lte->resource_location != RESOURCE_IN_WIM) + return WIM_COMPRESSION_TYPE_NONE; + return wimlib_get_compression_type(lte->wim); +} - /* When a WIM file is written, out_refcnt starts at 0 and is incremented - * whenever the file resource pointed to by this lookup table entry - * needs to be written. Naturally, the file resource only need to be - * written when out_refcnt is 0. Incrementing it further is needed to - * find the correct reference count to write to the lookup table in the - * output file, which may be less than the regular refcnt if not all - * images in the WIM file are written. - * - * output_resource_entry is the struct resource_entry for the position of the - * file resource when written to the output file. */ - union { - u32 out_refcnt; - bool refcnt_is_incremented; - }; - struct resource_entry output_resource_entry; -}; extern struct lookup_table *new_lookup_table(size_t capacity); -extern void lookup_table_insert(struct lookup_table *table, - struct lookup_table_entry *lte); - -extern void lookup_table_unlink(struct lookup_table *table, +extern void lookup_table_insert(struct lookup_table *table, struct lookup_table_entry *lte); -extern void lookup_table_decrement_refcnt(struct lookup_table* table, - const u8 hash[]); - +/* Unlinks a lookup table entry from the table; does not free it. */ +static inline void lookup_table_unlink(struct lookup_table *table, + struct lookup_table_entry *lte) +{ + hlist_del(<e->hash_list); + table->num_entries--; +} extern struct lookup_table_entry *new_lookup_table_entry(); -extern int for_lookup_table_entry(struct lookup_table *table, - int (*visitor)(struct lookup_table_entry *, void *), +extern struct lookup_table_entry * +clone_lookup_table_entry(const struct lookup_table_entry *lte); + +extern int for_lookup_table_entry(struct lookup_table *table, + int (*visitor)(struct lookup_table_entry *, void *), void *arg); -extern struct lookup_table_entry *lookup_resource(const struct lookup_table *table, - const u8 hash[]); +extern struct lookup_table_entry * +__lookup_resource(const struct lookup_table *table, const u8 hash[]); + +extern int lookup_resource(WIMStruct *w, const char *path, + int lookup_flags, struct dentry **dentry_ret, + struct lookup_table_entry **lte_ret, + u16 *stream_idx_ret); + +extern void lte_decrement_refcnt(struct lookup_table_entry *lte, + struct lookup_table *table); +#ifdef WITH_FUSE +extern void lte_decrement_num_opened_fds(struct lookup_table_entry *lte); +#endif + +extern int lte_zero_out_refcnt(struct lookup_table_entry *entry, void *ignore); +extern int lte_zero_real_refcnt(struct lookup_table_entry *entry, void *ignore); +extern int lte_zero_extracted_file(struct lookup_table_entry *lte, void *ignore); +extern int lte_free_extracted_file(struct lookup_table_entry *lte, void *ignore); + +extern void print_lookup_table_entry(const struct lookup_table_entry *entry); + +extern int read_lookup_table(WIMStruct *w); + +extern void free_lookup_table(struct lookup_table *table); + +extern int write_lookup_table_entry(struct lookup_table_entry *lte, void *__out); + +extern void free_lookup_table_entry(struct lookup_table_entry *lte); + +extern int dentry_resolve_ltes(struct dentry *dentry, void *__table); +extern int dentry_unresolve_ltes(struct dentry *dentry, void *ignore); + +int write_lookup_table(struct lookup_table *table, FILE *out, + struct resource_entry *out_res_entry); + +static inline struct resource_entry* wim_metadata_resource_entry(WIMStruct *w) +{ + return &w->image_metadata[ + w->current_image - 1].metadata_lte->resource_entry; +} static inline struct lookup_table_entry * -wim_lookup_resource(const WIMStruct *w, const struct dentry *dentry) +inode_stream_lte_resolved(const struct inode *inode, unsigned stream_idx) { - return lookup_resource(w->lookup_table, dentry->hash); + wimlib_assert(inode->resolved); + wimlib_assert(stream_idx <= inode->num_ads); + if (stream_idx == 0) + return inode->lte; + else + return inode->ads_entries[stream_idx - 1].lte; } -extern int zero_out_refcnts(struct lookup_table_entry *entry, void *ignore); +static inline struct lookup_table_entry * +inode_stream_lte_unresolved(const struct inode *inode, unsigned stream_idx, + const struct lookup_table *table) +{ + wimlib_assert(!inode->resolved); + wimlib_assert(stream_idx <= inode->num_ads); + if (!table) + return NULL; + if (stream_idx == 0) + return __lookup_resource(table, inode->hash); + else + return __lookup_resource(table, + inode->ads_entries[ + stream_idx - 1].hash); +} +/* + * Returns the lookup table entry for stream @stream_idx of the inode, where + * stream_idx = 0 means the default un-named file stream, and stream_idx >= 1 + * corresponds to an alternate data stream. + * + * This works for both resolved and un-resolved dentries. + */ +static inline struct lookup_table_entry * +inode_stream_lte(const struct inode *inode, unsigned stream_idx, + const struct lookup_table *table) +{ + if (inode->resolved) + return inode_stream_lte_resolved(inode, stream_idx); + else + return inode_stream_lte_unresolved(inode, stream_idx, table); +} -extern int print_lookup_table_entry(struct lookup_table_entry *entry, void *ignore); -extern int read_lookup_table(FILE *fp, u64 offset, u64 size, - struct lookup_table **table_ret); +static inline const u8 *inode_stream_hash_unresolved(const struct inode *inode, + unsigned stream_idx) +{ + wimlib_assert(!inode->resolved); + wimlib_assert(stream_idx <= inode->num_ads); + if (stream_idx == 0) + return inode->hash; + else + return inode->ads_entries[stream_idx - 1].hash; +} -extern void free_lookup_table(struct lookup_table *table); -extern int write_lookup_table_entry(struct lookup_table_entry *lte, void *__out); +static inline const u8 *inode_stream_hash_resolved(const struct inode *inode, + unsigned stream_idx) +{ + struct lookup_table_entry *lte; + lte = inode_stream_lte_resolved(inode, stream_idx); + if (lte) + return lte->hash; + else + return zero_hash; +} -static inline void free_lookup_table_entry(struct lookup_table_entry *lte) +/* + * Returns the hash for stream @stream_idx of the inode, where stream_idx = 0 + * means the default un-named file stream, and stream_idx >= 1 corresponds to an + * alternate data stream. + * + * This works for both resolved and un-resolved dentries. + */ +static inline const u8 *inode_stream_hash(const struct inode *inode, + unsigned stream_idx) { - if (lte) { - FREE(lte->file_on_disk); - FREE(lte); - } + if (inode->resolved) + return inode_stream_hash_resolved(inode, stream_idx); + else + return inode_stream_hash_unresolved(inode, stream_idx); } -/* Writes the lookup table to the output file. */ -static inline int write_lookup_table(struct lookup_table *table, FILE *out) +static inline u16 inode_stream_name_len(const struct inode *inode, + unsigned stream_idx) { - return for_lookup_table_entry(table, write_lookup_table_entry, out); + wimlib_assert(stream_idx <= inode->num_ads); + if (stream_idx == 0) + return 0; + else + return inode->ads_entries[stream_idx - 1].stream_name_len; } -/* Unlinks and frees an entry from a lookup table. */ -static inline void lookup_table_remove(struct lookup_table *table, - struct lookup_table_entry *lte) +static inline struct lookup_table_entry * +inode_unnamed_lte_resolved(const struct inode *inode) { - lookup_table_unlink(table, lte); - free_lookup_table_entry(lte); + wimlib_assert(inode->resolved); + for (unsigned i = 0; i <= inode->num_ads; i++) + if (inode_stream_name_len(inode, i) == 0 && + !is_zero_hash(inode_stream_hash_resolved(inode, i))) + return inode_stream_lte_resolved(inode, i); + return NULL; } -static inline struct resource_entry* wim_metadata_resource_entry(WIMStruct *w) +static inline struct lookup_table_entry * +inode_unnamed_lte_unresolved(const struct inode *inode, + const struct lookup_table *table) { - return &w->image_metadata[ - w->current_image - 1].metadata_lte->resource_entry; + wimlib_assert(!inode->resolved); + for (unsigned i = 0; i <= inode->num_ads; i++) + if (inode_stream_name_len(inode, i) == 0 && + !is_zero_hash(inode_stream_hash_unresolved(inode, i))) + return inode_stream_lte_unresolved(inode, i, table); + return NULL; } +extern struct lookup_table_entry * +inode_unnamed_lte(const struct inode *inode, + const struct lookup_table *table); + + #endif