diff options
Diffstat (limited to '')
| -rw-r--r-- | lib/ext2fs/inode.c | 1122 |
1 files changed, 1122 insertions, 0 deletions
diff --git a/lib/ext2fs/inode.c b/lib/ext2fs/inode.c new file mode 100644 index 0000000..957d5aa --- /dev/null +++ b/lib/ext2fs/inode.c @@ -0,0 +1,1122 @@ +/* + * inode.c --- utility routines to read and write inodes + * + * Copyright (C) 1993, 1994, 1995, 1996, 1997 Theodore Ts'o. + * + * %Begin-Header% + * This file may be redistributed under the terms of the GNU Library + * General Public License, version 2. + * %End-Header% + */ + +#include "config.h" +#include <stdio.h> +#include <string.h> +#if HAVE_UNISTD_H +#include <unistd.h> +#endif +#if HAVE_ERRNO_H +#include <errno.h> +#endif +#include <time.h> +#if HAVE_SYS_STAT_H +#include <sys/stat.h> +#endif +#if HAVE_SYS_TYPES_H +#include <sys/types.h> +#endif + +#include "ext2_fs.h" +#include "ext2fsP.h" +#include "e2image.h" + +#define IBLOCK_STATUS_CSUMS_OK 1 +#define IBLOCK_STATUS_INSANE 2 +#define SCAN_BLOCK_STATUS(scan) ((scan)->temp_buffer + (scan)->inode_size) + +struct ext2_struct_inode_scan { + errcode_t magic; + ext2_filsys fs; + ext2_ino_t current_inode; + blk64_t current_block; + dgrp_t current_group; + ext2_ino_t inodes_left; + blk_t blocks_left; + dgrp_t groups_left; + blk_t inode_buffer_blocks; + char * inode_buffer; + int inode_size; + char * ptr; + int bytes_left; + char *temp_buffer; + errcode_t (*done_group)(ext2_filsys fs, + ext2_inode_scan scan, + dgrp_t group, + void * priv_data); + void * done_group_data; + int bad_block_ptr; + int scan_flags; + int reserved[6]; +}; + +/* + * This routine flushes the icache, if it exists. + */ +errcode_t ext2fs_flush_icache(ext2_filsys fs) +{ + unsigned i; + + if (!fs->icache) + return 0; + + for (i=0; i < fs->icache->cache_size; i++) + fs->icache->cache[i].ino = 0; + + fs->icache->buffer_blk = 0; + return 0; +} + +/* + * Free the inode cache structure + */ +void ext2fs_free_inode_cache(struct ext2_inode_cache *icache) +{ + unsigned i; + + if (--icache->refcount) + return; + if (icache->buffer) + ext2fs_free_mem(&icache->buffer); + for (i = 0; i < icache->cache_size; i++) + ext2fs_free_mem(&icache->cache[i].inode); + if (icache->cache) + ext2fs_free_mem(&icache->cache); + icache->buffer_blk = 0; + ext2fs_free_mem(&icache); +} + +errcode_t ext2fs_create_inode_cache(ext2_filsys fs, unsigned int cache_size) +{ + unsigned i; + errcode_t retval; + + if (fs->icache) + return 0; + retval = ext2fs_get_mem(sizeof(struct ext2_inode_cache), &fs->icache); + if (retval) + return retval; + + memset(fs->icache, 0, sizeof(struct ext2_inode_cache)); + retval = ext2fs_get_mem(fs->blocksize, &fs->icache->buffer); + if (retval) + goto errout; + + fs->icache->buffer_blk = 0; + fs->icache->cache_last = -1; + fs->icache->cache_size = cache_size; + fs->icache->refcount = 1; + retval = ext2fs_get_array(fs->icache->cache_size, + sizeof(struct ext2_inode_cache_ent), + &fs->icache->cache); + if (retval) + goto errout; + + for (i = 0; i < fs->icache->cache_size; i++) { + retval = ext2fs_get_mem(EXT2_INODE_SIZE(fs->super), + &fs->icache->cache[i].inode); + if (retval) + goto errout; + } + + ext2fs_flush_icache(fs); + return 0; +errout: + ext2fs_free_inode_cache(fs->icache); + fs->icache = 0; + return retval; +} + +errcode_t ext2fs_open_inode_scan(ext2_filsys fs, int buffer_blocks, + ext2_inode_scan *ret_scan) +{ + ext2_inode_scan scan; + errcode_t retval; + errcode_t (*save_get_blocks)(ext2_filsys f, ext2_ino_t ino, blk_t *blocks); + + EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS); + + if (ext2fs_has_feature_journal_dev(fs->super)) + return EXT2_ET_EXTERNAL_JOURNAL_NOSUPP; + + if (fs->blocksize < 1024) + return EXT2_FILSYS_CORRUPTED; /* Should never happen */ + + /* + * If fs->badblocks isn't set, then set it --- since the inode + * scanning functions require it. + */ + if (fs->badblocks == 0) { + /* + * Temporarily save fs->get_blocks and set it to zero, + * for compatibility with old e2fsck's. + */ + save_get_blocks = fs->get_blocks; + fs->get_blocks = 0; + retval = ext2fs_read_bb_inode(fs, &fs->badblocks); + if (retval && fs->badblocks) { + ext2fs_badblocks_list_free(fs->badblocks); + fs->badblocks = 0; + } + fs->get_blocks = save_get_blocks; + } + + retval = ext2fs_get_mem(sizeof(struct ext2_struct_inode_scan), &scan); + if (retval) + return retval; + memset(scan, 0, sizeof(struct ext2_struct_inode_scan)); + + scan->magic = EXT2_ET_MAGIC_INODE_SCAN; + scan->fs = fs; + scan->inode_size = EXT2_INODE_SIZE(fs->super); + scan->bytes_left = 0; + scan->current_group = 0; + scan->groups_left = fs->group_desc_count - 1; + scan->inode_buffer_blocks = buffer_blocks ? buffer_blocks : + EXT2_INODE_SCAN_DEFAULT_BUFFER_BLOCKS; + scan->current_block = ext2fs_inode_table_loc(scan->fs, + scan->current_group); + if (scan->current_block && + ((scan->current_block < fs->super->s_first_data_block) || + (scan->current_block + fs->inode_blocks_per_group - 1 >= + ext2fs_blocks_count(fs->super)))) { + ext2fs_free_mem(&scan); + return EXT2_ET_GDESC_BAD_INODE_TABLE; + } + + scan->inodes_left = EXT2_INODES_PER_GROUP(scan->fs->super); + scan->blocks_left = scan->fs->inode_blocks_per_group; + if (ext2fs_has_group_desc_csum(fs)) { + __u32 unused = ext2fs_bg_itable_unused(fs, scan->current_group); + if (scan->inodes_left > unused) + scan->inodes_left -= unused; + else + scan->inodes_left = 0; + scan->blocks_left = + (scan->inodes_left + + (fs->blocksize / scan->inode_size - 1)) * + scan->inode_size / fs->blocksize; + } + retval = io_channel_alloc_buf(fs->io, scan->inode_buffer_blocks, + &scan->inode_buffer); + scan->done_group = 0; + scan->done_group_data = 0; + scan->bad_block_ptr = 0; + if (retval) { + ext2fs_free_mem(&scan); + return retval; + } + retval = ext2fs_get_mem(scan->inode_size + scan->inode_buffer_blocks, + &scan->temp_buffer); + if (retval) { + ext2fs_free_mem(&scan->inode_buffer); + ext2fs_free_mem(&scan); + return retval; + } + memset(SCAN_BLOCK_STATUS(scan), 0, scan->inode_buffer_blocks); + if (scan->fs->badblocks && scan->fs->badblocks->num) + scan->scan_flags |= EXT2_SF_CHK_BADBLOCKS; + if (ext2fs_has_group_desc_csum(fs)) + scan->scan_flags |= EXT2_SF_DO_LAZY; + *ret_scan = scan; + return 0; +} + +void ext2fs_close_inode_scan(ext2_inode_scan scan) +{ + if (!scan || (scan->magic != EXT2_ET_MAGIC_INODE_SCAN)) + return; + + ext2fs_free_mem(&scan->inode_buffer); + scan->inode_buffer = NULL; + ext2fs_free_mem(&scan->temp_buffer); + scan->temp_buffer = NULL; + ext2fs_free_mem(&scan); + return; +} + +void ext2fs_set_inode_callback(ext2_inode_scan scan, + errcode_t (*done_group)(ext2_filsys fs, + ext2_inode_scan scan, + dgrp_t group, + void * priv_data), + void *done_group_data) +{ + if (!scan || (scan->magic != EXT2_ET_MAGIC_INODE_SCAN)) + return; + + scan->done_group = done_group; + scan->done_group_data = done_group_data; +} + +int ext2fs_inode_scan_flags(ext2_inode_scan scan, int set_flags, + int clear_flags) +{ + int old_flags; + + if (!scan || (scan->magic != EXT2_ET_MAGIC_INODE_SCAN)) + return 0; + + old_flags = scan->scan_flags; + scan->scan_flags &= ~clear_flags; + scan->scan_flags |= set_flags; + return old_flags; +} + +/* + * This function is called by ext2fs_get_next_inode when it needs to + * get ready to read in a new blockgroup. + */ +static errcode_t get_next_blockgroup(ext2_inode_scan scan) +{ + ext2_filsys fs = scan->fs; + + scan->current_group++; + scan->groups_left--; + + scan->current_block = ext2fs_inode_table_loc(scan->fs, + scan->current_group); + scan->current_inode = scan->current_group * + EXT2_INODES_PER_GROUP(fs->super); + + scan->bytes_left = 0; + scan->inodes_left = EXT2_INODES_PER_GROUP(fs->super); + scan->blocks_left = fs->inode_blocks_per_group; + if (ext2fs_has_group_desc_csum(fs)) { + __u32 unused = ext2fs_bg_itable_unused(fs, scan->current_group); + if (scan->inodes_left > unused) + scan->inodes_left -= unused; + else + scan->inodes_left = 0; + scan->blocks_left = + (scan->inodes_left + + (fs->blocksize / scan->inode_size - 1)) * + scan->inode_size / fs->blocksize; + } + if (scan->current_block && + ((scan->current_block < fs->super->s_first_data_block) || + (scan->current_block + fs->inode_blocks_per_group - 1 >= + ext2fs_blocks_count(fs->super)))) + return EXT2_ET_GDESC_BAD_INODE_TABLE; + return 0; +} + +errcode_t ext2fs_inode_scan_goto_blockgroup(ext2_inode_scan scan, + int group) +{ + scan->current_group = group - 1; + scan->groups_left = scan->fs->group_desc_count - group; + scan->bad_block_ptr = 0; + return get_next_blockgroup(scan); +} + +/* + * This function is called by get_next_blocks() to check for bad + * blocks in the inode table. + * + * This function assumes that badblocks_list->list is sorted in + * increasing order. + */ +static errcode_t check_for_inode_bad_blocks(ext2_inode_scan scan, + blk64_t *num_blocks) +{ + blk64_t blk = scan->current_block; + badblocks_list bb = scan->fs->badblocks; + + /* + * If the inode table is missing, then obviously there are no + * bad blocks. :-) + */ + if (blk == 0) + return 0; + + /* Make sure bad_block_ptr is still valid */ + if (scan->bad_block_ptr >= bb->num) { + scan->scan_flags &= ~EXT2_SF_CHK_BADBLOCKS; + return 0; + } + + /* + * If the current block is greater than the bad block listed + * in the bad block list, then advance the pointer until this + * is no longer the case. If we run out of bad blocks, then + * we don't need to do any more checking! + */ + while (blk > bb->list[scan->bad_block_ptr]) { + if (++scan->bad_block_ptr >= bb->num) { + scan->scan_flags &= ~EXT2_SF_CHK_BADBLOCKS; + return 0; + } + } + + /* + * If the current block is equal to the bad block listed in + * the bad block list, then handle that one block specially. + * (We could try to handle runs of bad blocks, but that + * only increases CPU efficiency by a small amount, at the + * expense of a huge expense of code complexity, and for an + * uncommon case at that.) + */ + if (blk == bb->list[scan->bad_block_ptr]) { + scan->scan_flags |= EXT2_SF_BAD_INODE_BLK; + *num_blocks = 1; + if (++scan->bad_block_ptr >= bb->num) + scan->scan_flags &= ~EXT2_SF_CHK_BADBLOCKS; + return 0; + } + + /* + * If there is a bad block in the range that we're about to + * read in, adjust the number of blocks to read so that we we + * don't read in the bad block. (Then the next block to read + * will be the bad block, which is handled in the above case.) + */ + if ((blk + *num_blocks) > bb->list[scan->bad_block_ptr]) + *num_blocks = (int) (bb->list[scan->bad_block_ptr] - blk); + + return 0; +} + +static int block_map_looks_insane(ext2_filsys fs, + struct ext2_inode_large *inode) +{ + unsigned int i, bad; + + /* We're only interested in block mapped files, dirs, and symlinks */ + if ((inode->i_flags & EXT4_INLINE_DATA_FL) || + (inode->i_flags & EXT4_EXTENTS_FL)) + return 0; + if (!LINUX_S_ISREG(inode->i_mode) && + !LINUX_S_ISLNK(inode->i_mode) && + !LINUX_S_ISDIR(inode->i_mode)) + return 0; + if (LINUX_S_ISLNK(inode->i_mode) && + EXT2_I_SIZE(inode) <= sizeof(inode->i_block)) + return 0; + + /* Unused inodes probably aren't insane */ + if (inode->i_links_count == 0) + return 0; + + /* See if more than half the block maps are insane */ + for (i = 0, bad = 0; i < EXT2_N_BLOCKS; i++) + if (inode->i_block[i] != 0 && + (inode->i_block[i] < fs->super->s_first_data_block || + inode->i_block[i] >= ext2fs_blocks_count(fs->super))) + bad++; + return bad > EXT2_N_BLOCKS / 2; +} + +static int extent_head_looks_insane(struct ext2_inode_large *inode) +{ + if (!(inode->i_flags & EXT4_EXTENTS_FL) || + ext2fs_extent_header_verify(inode->i_block, + sizeof(inode->i_block)) == 0) + return 0; + return 1; +} + +/* + * Check all the inodes that we just read into the buffer. Record what we + * find here -- currently, we can observe that all checksums are ok; more + * than half the inodes are insane; or no conclusions at all. + */ +static void check_inode_block_sanity(ext2_inode_scan scan, blk64_t num_blocks) +{ + ext2_ino_t ino, inodes_to_scan; + unsigned int badness, checksum_failures; + unsigned int inodes_in_buf, inodes_per_block; + char *p; + struct ext2_inode_large *inode; + char *block_status; + unsigned int blk, bad_csum; + + if (!(scan->scan_flags & EXT2_SF_WARN_GARBAGE_INODES)) + return; + + inodes_to_scan = scan->inodes_left; + inodes_in_buf = num_blocks * scan->fs->blocksize / scan->inode_size; + if (inodes_to_scan > inodes_in_buf) + inodes_to_scan = inodes_in_buf; + + p = (char *) scan->inode_buffer; + ino = scan->current_inode + 1; + checksum_failures = badness = 0; + block_status = SCAN_BLOCK_STATUS(scan); + memset(block_status, 0, scan->inode_buffer_blocks); + inodes_per_block = EXT2_INODES_PER_BLOCK(scan->fs->super); + + if (inodes_per_block < 2) + return; + +#ifdef WORDS_BIGENDIAN + if (ext2fs_get_mem(EXT2_INODE_SIZE(scan->fs->super), &inode)) + return; +#endif + + while (inodes_to_scan > 0) { + blk = (p - (char *)scan->inode_buffer) / scan->fs->blocksize; + bad_csum = ext2fs_inode_csum_verify(scan->fs, ino, + (struct ext2_inode_large *) p) == 0; + +#ifdef WORDS_BIGENDIAN + ext2fs_swap_inode_full(scan->fs, + (struct ext2_inode_large *) inode, + (struct ext2_inode_large *) p, + 0, EXT2_INODE_SIZE(scan->fs->super)); +#else + inode = (struct ext2_inode_large *) p; +#endif + + /* Is this inode insane? */ + if (bad_csum) { + checksum_failures++; + badness++; + } else if (extent_head_looks_insane(inode) || + block_map_looks_insane(scan->fs, inode)) + badness++; + + /* If more than half are insane, declare the whole block bad */ + if (badness > inodes_per_block / 2) { + unsigned int ino_adj; + + block_status[blk] |= IBLOCK_STATUS_INSANE; + ino_adj = inodes_per_block - + ((ino - 1) % inodes_per_block); + if (ino_adj > inodes_to_scan) + ino_adj = inodes_to_scan; + inodes_to_scan -= ino_adj; + p += scan->inode_size * ino_adj; + ino += ino_adj; + checksum_failures = badness = 0; + continue; + } + + if ((ino % inodes_per_block) == 0) { + if (checksum_failures == 0) + block_status[blk] |= IBLOCK_STATUS_CSUMS_OK; + checksum_failures = badness = 0; + } + inodes_to_scan--; + p += scan->inode_size; + ino++; + }; + +#ifdef WORDS_BIGENDIAN + ext2fs_free_mem(&inode); +#endif +} + +/* + * This function is called by ext2fs_get_next_inode when it needs to + * read in more blocks from the current blockgroup's inode table. + */ +static errcode_t get_next_blocks(ext2_inode_scan scan) +{ + blk64_t num_blocks; + errcode_t retval; + + /* + * Figure out how many blocks to read; we read at most + * inode_buffer_blocks, and perhaps less if there aren't that + * many blocks left to read. + */ + num_blocks = scan->inode_buffer_blocks; + if (num_blocks > scan->blocks_left) + num_blocks = scan->blocks_left; + + /* + * If the past block "read" was a bad block, then mark the + * left-over extra bytes as also being bad. + */ + if (scan->scan_flags & EXT2_SF_BAD_INODE_BLK) { + if (scan->bytes_left) + scan->scan_flags |= EXT2_SF_BAD_EXTRA_BYTES; + scan->scan_flags &= ~EXT2_SF_BAD_INODE_BLK; + } + + /* + * Do inode bad block processing, if necessary. + */ + if (scan->scan_flags & EXT2_SF_CHK_BADBLOCKS) { + retval = check_for_inode_bad_blocks(scan, &num_blocks); + if (retval) + return retval; + } + + if ((scan->scan_flags & EXT2_SF_BAD_INODE_BLK) || + (scan->current_block == 0)) { + memset(scan->inode_buffer, 0, + (size_t) num_blocks * scan->fs->blocksize); + } else { + retval = io_channel_read_blk64(scan->fs->io, + scan->current_block, + (int) num_blocks, + scan->inode_buffer); + if (retval) + return EXT2_ET_NEXT_INODE_READ; + } + check_inode_block_sanity(scan, num_blocks); + + scan->ptr = scan->inode_buffer; + scan->bytes_left = num_blocks * scan->fs->blocksize; + + scan->blocks_left -= num_blocks; + if (scan->current_block) + scan->current_block += num_blocks; + + return 0; +} + +#if 0 +/* + * Returns 1 if the entire inode_buffer has a non-zero size and + * contains all zeros. (Not just deleted inodes, since that means + * that part of the inode table was used at one point; we want all + * zeros, which means that the inode table is pristine.) + */ +static inline int is_empty_scan(ext2_inode_scan scan) +{ + int i; + + if (scan->bytes_left == 0) + return 0; + + for (i=0; i < scan->bytes_left; i++) + if (scan->ptr[i]) + return 0; + return 1; +} +#endif + +errcode_t ext2fs_get_next_inode_full(ext2_inode_scan scan, ext2_ino_t *ino, + struct ext2_inode *inode, int bufsize) +{ + errcode_t retval; + int extra_bytes = 0; + int length; + struct ext2_inode_large *iptr = (struct ext2_inode_large *)inode; + char *iblock_status; + unsigned int iblk; + + EXT2_CHECK_MAGIC(scan, EXT2_ET_MAGIC_INODE_SCAN); + length = EXT2_INODE_SIZE(scan->fs->super); + iblock_status = SCAN_BLOCK_STATUS(scan); + + /* + * Do we need to start reading a new block group? + */ + if (scan->inodes_left <= 0) { + force_new_group: + if (scan->done_group) { + retval = (scan->done_group) + (scan->fs, scan, scan->current_group, + scan->done_group_data); + if (retval) + return retval; + } + if (scan->groups_left <= 0) { + *ino = 0; + return 0; + } + retval = get_next_blockgroup(scan); + if (retval) + return retval; + } + /* + * These checks are done outside the above if statement so + * they can be done for block group #0. + */ + if ((scan->scan_flags & EXT2_SF_DO_LAZY) && + (ext2fs_bg_flags_test(scan->fs, scan->current_group, EXT2_BG_INODE_UNINIT) + )) + goto force_new_group; + if (scan->inodes_left == 0) + goto force_new_group; + if (scan->current_block == 0) { + if (scan->scan_flags & EXT2_SF_SKIP_MISSING_ITABLE) { + goto force_new_group; + } else + return EXT2_ET_MISSING_INODE_TABLE; + } + + + /* + * Have we run out of space in the inode buffer? If so, we + * need to read in more blocks. + */ + if (scan->bytes_left < scan->inode_size) { + if (scan->bytes_left) + memcpy(scan->temp_buffer, scan->ptr, scan->bytes_left); + extra_bytes = scan->bytes_left; + + retval = get_next_blocks(scan); + if (retval) + return retval; +#if 0 + /* + * XXX test Need check for used inode somehow. + * (Note: this is hard.) + */ + if (is_empty_scan(scan)) + goto force_new_group; +#endif + } + + if (bufsize < length) { + retval = ext2fs_get_mem(length, &iptr); + if (retval) + return retval; + } + + retval = 0; + iblk = scan->current_inode % EXT2_INODES_PER_GROUP(scan->fs->super) / + EXT2_INODES_PER_BLOCK(scan->fs->super) % + scan->inode_buffer_blocks; + if (extra_bytes) { + memcpy(scan->temp_buffer+extra_bytes, scan->ptr, + scan->inode_size - extra_bytes); + scan->ptr += scan->inode_size - extra_bytes; + scan->bytes_left -= scan->inode_size - extra_bytes; + + /* Verify the inode checksum. */ + if (!(iblock_status[iblk] & IBLOCK_STATUS_CSUMS_OK) && + !(scan->fs->flags & EXT2_FLAG_IGNORE_CSUM_ERRORS) && + !ext2fs_inode_csum_verify(scan->fs, scan->current_inode + 1, + (struct ext2_inode_large *)scan->temp_buffer)) + retval = EXT2_ET_INODE_CSUM_INVALID; + +#ifdef WORDS_BIGENDIAN + memset(iptr, 0, length); + ext2fs_swap_inode_full(scan->fs, + (struct ext2_inode_large *) iptr, + (struct ext2_inode_large *) scan->temp_buffer, + 0, length); +#else + memcpy(iptr, scan->temp_buffer, length); +#endif + if (scan->scan_flags & EXT2_SF_BAD_EXTRA_BYTES) + retval = EXT2_ET_BAD_BLOCK_IN_INODE_TABLE; + scan->scan_flags &= ~EXT2_SF_BAD_EXTRA_BYTES; + } else { + /* Verify the inode checksum. */ + if (!(iblock_status[iblk] & IBLOCK_STATUS_CSUMS_OK) && + !(scan->fs->flags & EXT2_FLAG_IGNORE_CSUM_ERRORS) && + !ext2fs_inode_csum_verify(scan->fs, scan->current_inode + 1, + (struct ext2_inode_large *)scan->ptr)) + retval = EXT2_ET_INODE_CSUM_INVALID; + +#ifdef WORDS_BIGENDIAN + memset(iptr, 0, length); + ext2fs_swap_inode_full(scan->fs, + (struct ext2_inode_large *) iptr, + (struct ext2_inode_large *) scan->ptr, + 0, length); +#else + memcpy(iptr, scan->ptr, length); +#endif + scan->ptr += scan->inode_size; + scan->bytes_left -= scan->inode_size; + if (scan->scan_flags & EXT2_SF_BAD_INODE_BLK) + retval = EXT2_ET_BAD_BLOCK_IN_INODE_TABLE; + } + if ((iblock_status[iblk] & IBLOCK_STATUS_INSANE) && + (retval == 0 || retval == EXT2_ET_INODE_CSUM_INVALID)) + retval = EXT2_ET_INODE_IS_GARBAGE; + + scan->inodes_left--; + scan->current_inode++; + *ino = scan->current_inode; + if (iptr != (struct ext2_inode_large *)inode) { + memcpy(inode, iptr, bufsize); + ext2fs_free_mem(&iptr); + } + return retval; +} + +errcode_t ext2fs_get_next_inode(ext2_inode_scan scan, ext2_ino_t *ino, + struct ext2_inode *inode) +{ + return ext2fs_get_next_inode_full(scan, ino, inode, + sizeof(struct ext2_inode)); +} + +/* + * Functions to read and write a single inode. + */ +errcode_t ext2fs_read_inode2(ext2_filsys fs, ext2_ino_t ino, + struct ext2_inode * inode, int bufsize, + int flags) +{ + blk64_t block_nr; + dgrp_t group; + unsigned long block, offset; + char *ptr; + errcode_t retval; + unsigned i; + int clen, inodes_per_block; + io_channel io; + int length = EXT2_INODE_SIZE(fs->super); + struct ext2_inode_large *iptr; + int cache_slot, fail_csum; + + EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS); + + if (ext2fs_has_feature_journal_dev(fs->super)) + return EXT2_ET_EXTERNAL_JOURNAL_NOSUPP; + + if (fs->blocksize < 1024) + return EXT2_FILSYS_CORRUPTED; /* Should never happen */ + + /* Check to see if user has an override function */ + if (fs->read_inode && + ((bufsize == sizeof(struct ext2_inode)) || + (EXT2_INODE_SIZE(fs->super) == sizeof(struct ext2_inode)))) { + retval = (fs->read_inode)(fs, ino, inode); + if (retval != EXT2_ET_CALLBACK_NOTHANDLED) + return retval; + } + if ((ino == 0) || (ino > fs->super->s_inodes_count)) + return EXT2_ET_BAD_INODE_NUM; + /* Create inode cache if not present */ + if (!fs->icache) { + retval = ext2fs_create_inode_cache(fs, 4); + if (retval) + return retval; + } + /* Check to see if it's in the inode cache */ + for (i = 0; i < fs->icache->cache_size; i++) { + if (fs->icache->cache[i].ino == ino) { + memcpy(inode, fs->icache->cache[i].inode, + (bufsize > length) ? length : bufsize); + return 0; + } + } + if (fs->flags & EXT2_FLAG_IMAGE_FILE) { + inodes_per_block = fs->blocksize / EXT2_INODE_SIZE(fs->super); + block_nr = ext2fs_le32_to_cpu(fs->image_header->offset_inode) / fs->blocksize; + block_nr += (ino - 1) / inodes_per_block; + offset = ((ino - 1) % inodes_per_block) * + EXT2_INODE_SIZE(fs->super); + io = fs->image_io; + } else { + group = (ino - 1) / EXT2_INODES_PER_GROUP(fs->super); + if (group > fs->group_desc_count) + return EXT2_ET_BAD_INODE_NUM; + offset = ((ino - 1) % EXT2_INODES_PER_GROUP(fs->super)) * + EXT2_INODE_SIZE(fs->super); + block = offset >> EXT2_BLOCK_SIZE_BITS(fs->super); + block_nr = ext2fs_inode_table_loc(fs, group); + if (!block_nr) + return EXT2_ET_MISSING_INODE_TABLE; + if ((block_nr < fs->super->s_first_data_block) || + (block_nr + fs->inode_blocks_per_group - 1 >= + ext2fs_blocks_count(fs->super))) + return EXT2_ET_GDESC_BAD_INODE_TABLE; + block_nr += block; + io = fs->io; + } + offset &= (EXT2_BLOCK_SIZE(fs->super) - 1); + + cache_slot = (fs->icache->cache_last + 1) % fs->icache->cache_size; + iptr = (struct ext2_inode_large *)fs->icache->cache[cache_slot].inode; + + ptr = (char *) iptr; + while (length) { + clen = length; + if ((offset + length) > fs->blocksize) + clen = fs->blocksize - offset; + + if (block_nr != fs->icache->buffer_blk) { + retval = io_channel_read_blk64(io, block_nr, 1, + fs->icache->buffer); + if (retval) + return retval; + fs->icache->buffer_blk = block_nr; + } + + memcpy(ptr, ((char *) fs->icache->buffer) + (unsigned) offset, + clen); + + offset = 0; + length -= clen; + ptr += clen; + block_nr++; + } + length = EXT2_INODE_SIZE(fs->super); + + /* Verify the inode checksum. */ + fail_csum = !ext2fs_inode_csum_verify(fs, ino, iptr); + +#ifdef WORDS_BIGENDIAN + ext2fs_swap_inode_full(fs, (struct ext2_inode_large *) iptr, + (struct ext2_inode_large *) iptr, + 0, length); +#endif + + /* Update the inode cache bookkeeping */ + if (!fail_csum) { + fs->icache->cache_last = cache_slot; + fs->icache->cache[cache_slot].ino = ino; + } + memcpy(inode, iptr, (bufsize > length) ? length : bufsize); + + if (!(fs->flags & EXT2_FLAG_IGNORE_CSUM_ERRORS) && + !(flags & READ_INODE_NOCSUM) && fail_csum) + return EXT2_ET_INODE_CSUM_INVALID; + + return 0; +} + +errcode_t ext2fs_read_inode_full(ext2_filsys fs, ext2_ino_t ino, + struct ext2_inode * inode, int bufsize) +{ + return ext2fs_read_inode2(fs, ino, inode, bufsize, 0); +} + +errcode_t ext2fs_read_inode(ext2_filsys fs, ext2_ino_t ino, + struct ext2_inode * inode) +{ + return ext2fs_read_inode2(fs, ino, inode, + sizeof(struct ext2_inode), 0); +} + +errcode_t ext2fs_write_inode2(ext2_filsys fs, ext2_ino_t ino, + struct ext2_inode * inode, int bufsize, + int flags) +{ + blk64_t block_nr; + dgrp_t group; + unsigned long block, offset; + errcode_t retval = 0; + struct ext2_inode_large *w_inode; + char *ptr; + unsigned i; + int clen; + int length = EXT2_INODE_SIZE(fs->super); + + EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS); + + if (ext2fs_has_feature_journal_dev(fs->super)) + return EXT2_ET_EXTERNAL_JOURNAL_NOSUPP; + + /* Check to see if user provided an override function */ + if (fs->write_inode) { + retval = (fs->write_inode)(fs, ino, inode); + if (retval != EXT2_ET_CALLBACK_NOTHANDLED) + return retval; + } + + if ((ino == 0) || (ino > fs->super->s_inodes_count)) + return EXT2_ET_BAD_INODE_NUM; + + /* Prepare our shadow buffer for read/modify/byteswap/write */ + retval = ext2fs_get_mem(length, &w_inode); + if (retval) + return retval; + + if (bufsize < length) { + retval = ext2fs_read_inode2(fs, ino, + (struct ext2_inode *)w_inode, + length, READ_INODE_NOCSUM); + if (retval) + goto errout; + } + + /* Check to see if the inode cache needs to be updated */ + if (fs->icache) { + for (i=0; i < fs->icache->cache_size; i++) { + if (fs->icache->cache[i].ino == ino) { + memcpy(fs->icache->cache[i].inode, inode, + (bufsize > length) ? length : bufsize); + break; + } + } + } else { + retval = ext2fs_create_inode_cache(fs, 4); + if (retval) + goto errout; + } + memcpy(w_inode, inode, (bufsize > length) ? length : bufsize); + + if (!(fs->flags & EXT2_FLAG_RW)) { + retval = EXT2_ET_RO_FILSYS; + goto errout; + } + +#ifdef WORDS_BIGENDIAN + ext2fs_swap_inode_full(fs, w_inode, w_inode, 1, length); +#endif + + if ((flags & WRITE_INODE_NOCSUM) == 0) { + retval = ext2fs_inode_csum_set(fs, ino, w_inode); + if (retval) + goto errout; + } + + group = (ino - 1) / EXT2_INODES_PER_GROUP(fs->super); + offset = ((ino - 1) % EXT2_INODES_PER_GROUP(fs->super)) * + EXT2_INODE_SIZE(fs->super); + block = offset >> EXT2_BLOCK_SIZE_BITS(fs->super); + block_nr = ext2fs_inode_table_loc(fs, (unsigned) group); + if (!block_nr) { + retval = EXT2_ET_MISSING_INODE_TABLE; + goto errout; + } + if ((block_nr < fs->super->s_first_data_block) || + (block_nr + fs->inode_blocks_per_group - 1 >= + ext2fs_blocks_count(fs->super))) { + retval = EXT2_ET_GDESC_BAD_INODE_TABLE; + goto errout; + } + block_nr += block; + + offset &= (EXT2_BLOCK_SIZE(fs->super) - 1); + + ptr = (char *) w_inode; + + while (length) { + clen = length; + if ((offset + length) > fs->blocksize) + clen = fs->blocksize - offset; + + if (fs->icache->buffer_blk != block_nr) { + retval = io_channel_read_blk64(fs->io, block_nr, 1, + fs->icache->buffer); + if (retval) + goto errout; + fs->icache->buffer_blk = block_nr; + } + + + memcpy((char *) fs->icache->buffer + (unsigned) offset, + ptr, clen); + + retval = io_channel_write_blk64(fs->io, block_nr, 1, + fs->icache->buffer); + if (retval) + goto errout; + + offset = 0; + ptr += clen; + length -= clen; + block_nr++; + } + + fs->flags |= EXT2_FLAG_CHANGED; +errout: + ext2fs_free_mem(&w_inode); + return retval; +} + +errcode_t ext2fs_write_inode_full(ext2_filsys fs, ext2_ino_t ino, + struct ext2_inode * inode, int bufsize) +{ + return ext2fs_write_inode2(fs, ino, inode, bufsize, 0); +} + +errcode_t ext2fs_write_inode(ext2_filsys fs, ext2_ino_t ino, + struct ext2_inode *inode) +{ + return ext2fs_write_inode2(fs, ino, inode, + sizeof(struct ext2_inode), 0); +} + +/* + * This function should be called when writing a new inode. It makes + * sure that extra part of large inodes is initialized properly. + */ +errcode_t ext2fs_write_new_inode(ext2_filsys fs, ext2_ino_t ino, + struct ext2_inode *inode) +{ + struct ext2_inode *buf; + int size = EXT2_INODE_SIZE(fs->super); + struct ext2_inode_large *large_inode; + errcode_t retval; + __u32 t = fs->now ? fs->now : time(NULL); + + if (!inode->i_ctime) + inode->i_ctime = t; + if (!inode->i_mtime) + inode->i_mtime = t; + if (!inode->i_atime) + inode->i_atime = t; + + if (size == sizeof(struct ext2_inode)) + return ext2fs_write_inode_full(fs, ino, inode, + sizeof(struct ext2_inode)); + + buf = malloc(size); + if (!buf) + return ENOMEM; + + memset(buf, 0, size); + *buf = *inode; + + large_inode = (struct ext2_inode_large *) buf; + large_inode->i_extra_isize = sizeof(struct ext2_inode_large) - + EXT2_GOOD_OLD_INODE_SIZE; + if (!large_inode->i_crtime) + large_inode->i_crtime = t; + + retval = ext2fs_write_inode_full(fs, ino, buf, size); + free(buf); + return retval; +} + + +errcode_t ext2fs_get_blocks(ext2_filsys fs, ext2_ino_t ino, blk_t *blocks) +{ + struct ext2_inode inode; + int i; + errcode_t retval; + + EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS); + + if (ino > fs->super->s_inodes_count) + return EXT2_ET_BAD_INODE_NUM; + + if (fs->get_blocks) { + if (!(*fs->get_blocks)(fs, ino, blocks)) + return 0; + } + retval = ext2fs_read_inode(fs, ino, &inode); + if (retval) + return retval; + for (i=0; i < EXT2_N_BLOCKS; i++) + blocks[i] = inode.i_block[i]; + return 0; +} + +errcode_t ext2fs_check_directory(ext2_filsys fs, ext2_ino_t ino) +{ + struct ext2_inode inode; + errcode_t retval; + + EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS); + + if (ino > fs->super->s_inodes_count) + return EXT2_ET_BAD_INODE_NUM; + + if (fs->check_directory) { + retval = (fs->check_directory)(fs, ino); + if (retval != EXT2_ET_CALLBACK_NOTHANDLED) + return retval; + } + retval = ext2fs_read_inode(fs, ino, &inode); + if (retval) + return retval; + if (!LINUX_S_ISDIR(inode.i_mode)) + return EXT2_ET_NO_DIRECTORY; + return 0; +} + |