Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   1) // SPDX-License-Identifier: GPL-2.0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   3)  *  linux/fs/ext2/dir.c
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   4)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   5)  * Copyright (C) 1992, 1993, 1994, 1995
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   6)  * Remy Card (card@masi.ibp.fr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   7)  * Laboratoire MASI - Institut Blaise Pascal
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   8)  * Universite Pierre et Marie Curie (Paris VI)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   9)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  10)  *  from
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  11)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  12)  *  linux/fs/minix/dir.c
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  13)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  14)  *  Copyright (C) 1991, 1992  Linus Torvalds
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  15)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  16)  *  ext2 directory handling functions
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  17)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  18)  *  Big-endian to little-endian byte-swapping/bitmaps by
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  19)  *        David S. Miller (davem@caip.rutgers.edu), 1995
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  20)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  21)  * All code that works with directory layout had been switched to pagecache
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  22)  * and moved here. AV
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  23)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  24) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  25) #include "ext2.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  26) #include <linux/buffer_head.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  27) #include <linux/pagemap.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  28) #include <linux/swap.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  29) #include <linux/iversion.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  30) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  31) typedef struct ext2_dir_entry_2 ext2_dirent;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  32) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  33) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  34)  * Tests against MAX_REC_LEN etc were put in place for 64k block
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  35)  * sizes; if that is not possible on this arch, we can skip
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  36)  * those tests and speed things up.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  37)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  38) static inline unsigned ext2_rec_len_from_disk(__le16 dlen)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  39) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  40) 	unsigned len = le16_to_cpu(dlen);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  41) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  42) #if (PAGE_SIZE >= 65536)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  43) 	if (len == EXT2_MAX_REC_LEN)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  44) 		return 1 << 16;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  45) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  46) 	return len;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  47) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  48) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  49) static inline __le16 ext2_rec_len_to_disk(unsigned len)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  50) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  51) #if (PAGE_SIZE >= 65536)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  52) 	if (len == (1 << 16))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  53) 		return cpu_to_le16(EXT2_MAX_REC_LEN);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  54) 	else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  55) 		BUG_ON(len > (1 << 16));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  56) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  57) 	return cpu_to_le16(len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  58) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  59) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  60) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  61)  * ext2 uses block-sized chunks. Arguably, sector-sized ones would be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  62)  * more robust, but we have what we have
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  63)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  64) static inline unsigned ext2_chunk_size(struct inode *inode)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  65) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  66) 	return inode->i_sb->s_blocksize;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  67) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  68) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  69) static inline void ext2_put_page(struct page *page)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  70) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  71) 	kunmap(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  72) 	put_page(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  73) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  74) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  75) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  76)  * Return the offset into page `page_nr' of the last valid
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  77)  * byte in that page, plus one.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  78)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  79) static unsigned
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  80) ext2_last_byte(struct inode *inode, unsigned long page_nr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  81) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  82) 	unsigned last_byte = inode->i_size;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  83) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  84) 	last_byte -= page_nr << PAGE_SHIFT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  85) 	if (last_byte > PAGE_SIZE)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  86) 		last_byte = PAGE_SIZE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  87) 	return last_byte;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  88) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  89) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  90) static int ext2_commit_chunk(struct page *page, loff_t pos, unsigned len)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  91) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  92) 	struct address_space *mapping = page->mapping;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  93) 	struct inode *dir = mapping->host;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  94) 	int err = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  95) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  96) 	inode_inc_iversion(dir);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  97) 	block_write_end(NULL, mapping, pos, len, len, page, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  98) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  99) 	if (pos+len > dir->i_size) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) 		i_size_write(dir, pos+len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) 		mark_inode_dirty(dir);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) 	if (IS_DIRSYNC(dir)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) 		err = write_one_page(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) 		if (!err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) 			err = sync_inode_metadata(dir, 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) 	} else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) 		unlock_page(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) 	return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) static bool ext2_check_page(struct page *page, int quiet)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) 	struct inode *dir = page->mapping->host;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) 	struct super_block *sb = dir->i_sb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) 	unsigned chunk_size = ext2_chunk_size(dir);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) 	char *kaddr = page_address(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) 	u32 max_inumber = le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) 	unsigned offs, rec_len;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) 	unsigned limit = PAGE_SIZE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) 	ext2_dirent *p;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) 	char *error;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) 	if ((dir->i_size >> PAGE_SHIFT) == page->index) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) 		limit = dir->i_size & ~PAGE_MASK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) 		if (limit & (chunk_size - 1))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) 			goto Ebadsize;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) 		if (!limit)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) 			goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) 	for (offs = 0; offs <= limit - EXT2_DIR_REC_LEN(1); offs += rec_len) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) 		p = (ext2_dirent *)(kaddr + offs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) 		rec_len = ext2_rec_len_from_disk(p->rec_len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) 		if (unlikely(rec_len < EXT2_DIR_REC_LEN(1)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) 			goto Eshort;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) 		if (unlikely(rec_len & 3))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) 			goto Ealign;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) 		if (unlikely(rec_len < EXT2_DIR_REC_LEN(p->name_len)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) 			goto Enamelen;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) 		if (unlikely(((offs + rec_len - 1) ^ offs) & ~(chunk_size-1)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) 			goto Espan;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) 		if (unlikely(le32_to_cpu(p->inode) > max_inumber))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) 			goto Einumber;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) 	if (offs != limit)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) 		goto Eend;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) out:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) 	SetPageChecked(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) 	return true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) 	/* Too bad, we had an error */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) Ebadsize:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) 	if (!quiet)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) 		ext2_error(sb, __func__,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) 			"size of directory #%lu is not a multiple "
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) 			"of chunk size", dir->i_ino);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) 	goto fail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) Eshort:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) 	error = "rec_len is smaller than minimal";
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) 	goto bad_entry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) Ealign:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) 	error = "unaligned directory entry";
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) 	goto bad_entry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) Enamelen:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) 	error = "rec_len is too small for name_len";
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) 	goto bad_entry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) Espan:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) 	error = "directory entry across blocks";
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) 	goto bad_entry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) Einumber:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) 	error = "inode out of bounds";
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) bad_entry:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) 	if (!quiet)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) 		ext2_error(sb, __func__, "bad entry in directory #%lu: : %s - "
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) 			"offset=%lu, inode=%lu, rec_len=%d, name_len=%d",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) 			dir->i_ino, error, (page->index<<PAGE_SHIFT)+offs,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) 			(unsigned long) le32_to_cpu(p->inode),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) 			rec_len, p->name_len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) 	goto fail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) Eend:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) 	if (!quiet) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) 		p = (ext2_dirent *)(kaddr + offs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) 		ext2_error(sb, "ext2_check_page",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) 			"entry in directory #%lu spans the page boundary"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) 			"offset=%lu, inode=%lu",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) 			dir->i_ino, (page->index<<PAGE_SHIFT)+offs,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) 			(unsigned long) le32_to_cpu(p->inode));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) fail:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) 	SetPageError(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) 	return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) static struct page * ext2_get_page(struct inode *dir, unsigned long n,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) 				   int quiet)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) 	struct address_space *mapping = dir->i_mapping;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) 	struct page *page = read_mapping_page(mapping, n, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) 	if (!IS_ERR(page)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) 		kmap(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) 		if (unlikely(!PageChecked(page))) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) 			if (PageError(page) || !ext2_check_page(page, quiet))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) 				goto fail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) 	return page;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) fail:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) 	ext2_put_page(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) 	return ERR_PTR(-EIO);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219)  * NOTE! unlike strncmp, ext2_match returns 1 for success, 0 for failure.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221)  * len <= EXT2_NAME_LEN and de != NULL are guaranteed by caller.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) static inline int ext2_match (int len, const char * const name,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) 					struct ext2_dir_entry_2 * de)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) 	if (len != de->name_len)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) 		return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) 	if (!de->inode)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) 		return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) 	return !memcmp(name, de->name, len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234)  * p is at least 6 bytes before the end of page
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) static inline ext2_dirent *ext2_next_entry(ext2_dirent *p)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) 	return (ext2_dirent *)((char *)p +
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) 			ext2_rec_len_from_disk(p->rec_len));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) static inline unsigned 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) ext2_validate_entry(char *base, unsigned offset, unsigned mask)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) 	ext2_dirent *de = (ext2_dirent*)(base + offset);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) 	ext2_dirent *p = (ext2_dirent*)(base + (offset&mask));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) 	while ((char*)p < (char*)de) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) 		if (p->rec_len == 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249) 			break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) 		p = ext2_next_entry(p);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) 	return (char *)p - base;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) static inline void ext2_set_de_type(ext2_dirent *de, struct inode *inode)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257) 	if (EXT2_HAS_INCOMPAT_FEATURE(inode->i_sb, EXT2_FEATURE_INCOMPAT_FILETYPE))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258) 		de->file_type = fs_umode_to_ftype(inode->i_mode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259) 	else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260) 		de->file_type = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263) static int
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) ext2_readdir(struct file *file, struct dir_context *ctx)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) 	loff_t pos = ctx->pos;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267) 	struct inode *inode = file_inode(file);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268) 	struct super_block *sb = inode->i_sb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) 	unsigned int offset = pos & ~PAGE_MASK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) 	unsigned long n = pos >> PAGE_SHIFT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271) 	unsigned long npages = dir_pages(inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) 	unsigned chunk_mask = ~(ext2_chunk_size(inode)-1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) 	bool need_revalidate = !inode_eq_iversion(inode, file->f_version);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) 	bool has_filetype;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) 	if (pos > inode->i_size - EXT2_DIR_REC_LEN(1))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) 		return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279) 	has_filetype =
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) 		EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_FILETYPE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282) 	for ( ; n < npages; n++, offset = 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) 		char *kaddr, *limit;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284) 		ext2_dirent *de;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285) 		struct page *page = ext2_get_page(inode, n, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287) 		if (IS_ERR(page)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288) 			ext2_error(sb, __func__,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289) 				   "bad page in #%lu",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290) 				   inode->i_ino);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291) 			ctx->pos += PAGE_SIZE - offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292) 			return PTR_ERR(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294) 		kaddr = page_address(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295) 		if (unlikely(need_revalidate)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296) 			if (offset) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297) 				offset = ext2_validate_entry(kaddr, offset, chunk_mask);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298) 				ctx->pos = (n<<PAGE_SHIFT) + offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299) 			}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300) 			file->f_version = inode_query_iversion(inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301) 			need_revalidate = false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 303) 		de = (ext2_dirent *)(kaddr+offset);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 304) 		limit = kaddr + ext2_last_byte(inode, n) - EXT2_DIR_REC_LEN(1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 305) 		for ( ;(char*)de <= limit; de = ext2_next_entry(de)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 306) 			if (de->rec_len == 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 307) 				ext2_error(sb, __func__,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 308) 					"zero-length directory entry");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 309) 				ext2_put_page(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 310) 				return -EIO;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 311) 			}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 312) 			if (de->inode) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 313) 				unsigned char d_type = DT_UNKNOWN;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 314) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 315) 				if (has_filetype)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 316) 					d_type = fs_ftype_to_dtype(de->file_type);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 317) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 318) 				if (!dir_emit(ctx, de->name, de->name_len,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 319) 						le32_to_cpu(de->inode),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 320) 						d_type)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 321) 					ext2_put_page(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 322) 					return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 323) 				}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 324) 			}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 325) 			ctx->pos += ext2_rec_len_from_disk(de->rec_len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 326) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 327) 		ext2_put_page(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 328) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 329) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 330) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 331) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 332) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 333)  *	ext2_find_entry()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 334)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 335)  * finds an entry in the specified directory with the wanted name. It
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 336)  * returns the page in which the entry was found (as a parameter - res_page),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 337)  * and the entry itself. Page is returned mapped and unlocked.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 338)  * Entry is guaranteed to be valid.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 339)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 340) struct ext2_dir_entry_2 *ext2_find_entry (struct inode *dir,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 341) 			const struct qstr *child, struct page **res_page)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 342) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 343) 	const char *name = child->name;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 344) 	int namelen = child->len;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 345) 	unsigned reclen = EXT2_DIR_REC_LEN(namelen);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 346) 	unsigned long start, n;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 347) 	unsigned long npages = dir_pages(dir);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 348) 	struct page *page = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 349) 	struct ext2_inode_info *ei = EXT2_I(dir);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 350) 	ext2_dirent * de;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 351) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 352) 	if (npages == 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 353) 		goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 354) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 355) 	/* OFFSET_CACHE */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 356) 	*res_page = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 357) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 358) 	start = ei->i_dir_start_lookup;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 359) 	if (start >= npages)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 360) 		start = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 361) 	n = start;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 362) 	do {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 363) 		char *kaddr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 364) 		page = ext2_get_page(dir, n, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 365) 		if (IS_ERR(page))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 366) 			return ERR_CAST(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 367) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 368) 		kaddr = page_address(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 369) 		de = (ext2_dirent *) kaddr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 370) 		kaddr += ext2_last_byte(dir, n) - reclen;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 371) 		while ((char *) de <= kaddr) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 372) 			if (de->rec_len == 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 373) 				ext2_error(dir->i_sb, __func__,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 374) 					"zero-length directory entry");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 375) 				ext2_put_page(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 376) 				goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 377) 			}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 378) 			if (ext2_match(namelen, name, de))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 379) 				goto found;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 380) 			de = ext2_next_entry(de);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 381) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 382) 		ext2_put_page(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 383) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 384) 		if (++n >= npages)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 385) 			n = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 386) 		/* next page is past the blocks we've got */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 387) 		if (unlikely(n > (dir->i_blocks >> (PAGE_SHIFT - 9)))) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 388) 			ext2_error(dir->i_sb, __func__,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 389) 				"dir %lu size %lld exceeds block count %llu",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 390) 				dir->i_ino, dir->i_size,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 391) 				(unsigned long long)dir->i_blocks);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 392) 			goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 393) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 394) 	} while (n != start);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 395) out:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 396) 	return ERR_PTR(-ENOENT);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 397) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 398) found:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 399) 	*res_page = page;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 400) 	ei->i_dir_start_lookup = n;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 401) 	return de;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 402) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 403) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 404) struct ext2_dir_entry_2 * ext2_dotdot (struct inode *dir, struct page **p)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 405) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 406) 	struct page *page = ext2_get_page(dir, 0, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 407) 	ext2_dirent *de = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 408) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 409) 	if (!IS_ERR(page)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 410) 		de = ext2_next_entry((ext2_dirent *) page_address(page));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 411) 		*p = page;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 412) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 413) 	return de;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 414) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 415) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 416) int ext2_inode_by_name(struct inode *dir, const struct qstr *child, ino_t *ino)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 417) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 418) 	struct ext2_dir_entry_2 *de;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 419) 	struct page *page;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 420) 	
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 421) 	de = ext2_find_entry(dir, child, &page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 422) 	if (IS_ERR(de))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 423) 		return PTR_ERR(de);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 424) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 425) 	*ino = le32_to_cpu(de->inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 426) 	ext2_put_page(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 427) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 428) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 429) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 430) static int ext2_prepare_chunk(struct page *page, loff_t pos, unsigned len)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 431) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 432) 	return __block_write_begin(page, pos, len, ext2_get_block);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 433) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 434) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 435) /* Releases the page */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 436) void ext2_set_link(struct inode *dir, struct ext2_dir_entry_2 *de,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 437) 		   struct page *page, struct inode *inode, int update_times)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 438) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 439) 	loff_t pos = page_offset(page) +
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 440) 			(char *) de - (char *) page_address(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 441) 	unsigned len = ext2_rec_len_from_disk(de->rec_len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 442) 	int err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 443) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 444) 	lock_page(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 445) 	err = ext2_prepare_chunk(page, pos, len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 446) 	BUG_ON(err);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 447) 	de->inode = cpu_to_le32(inode->i_ino);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 448) 	ext2_set_de_type(de, inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 449) 	err = ext2_commit_chunk(page, pos, len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 450) 	ext2_put_page(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 451) 	if (update_times)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 452) 		dir->i_mtime = dir->i_ctime = current_time(dir);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 453) 	EXT2_I(dir)->i_flags &= ~EXT2_BTREE_FL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 454) 	mark_inode_dirty(dir);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 455) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 456) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 457) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 458)  *	Parent is locked.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 459)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 460) int ext2_add_link (struct dentry *dentry, struct inode *inode)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 461) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 462) 	struct inode *dir = d_inode(dentry->d_parent);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 463) 	const char *name = dentry->d_name.name;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 464) 	int namelen = dentry->d_name.len;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 465) 	unsigned chunk_size = ext2_chunk_size(dir);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 466) 	unsigned reclen = EXT2_DIR_REC_LEN(namelen);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 467) 	unsigned short rec_len, name_len;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 468) 	struct page *page = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 469) 	ext2_dirent * de;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 470) 	unsigned long npages = dir_pages(dir);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 471) 	unsigned long n;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 472) 	char *kaddr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 473) 	loff_t pos;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 474) 	int err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 475) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 476) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 477) 	 * We take care of directory expansion in the same loop.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 478) 	 * This code plays outside i_size, so it locks the page
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 479) 	 * to protect that region.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 480) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 481) 	for (n = 0; n <= npages; n++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 482) 		char *dir_end;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 483) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 484) 		page = ext2_get_page(dir, n, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 485) 		err = PTR_ERR(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 486) 		if (IS_ERR(page))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 487) 			goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 488) 		lock_page(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 489) 		kaddr = page_address(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 490) 		dir_end = kaddr + ext2_last_byte(dir, n);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 491) 		de = (ext2_dirent *)kaddr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 492) 		kaddr += PAGE_SIZE - reclen;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 493) 		while ((char *)de <= kaddr) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 494) 			if ((char *)de == dir_end) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 495) 				/* We hit i_size */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 496) 				name_len = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 497) 				rec_len = chunk_size;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 498) 				de->rec_len = ext2_rec_len_to_disk(chunk_size);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 499) 				de->inode = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 500) 				goto got_it;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 501) 			}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 502) 			if (de->rec_len == 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 503) 				ext2_error(dir->i_sb, __func__,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 504) 					"zero-length directory entry");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 505) 				err = -EIO;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 506) 				goto out_unlock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 507) 			}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 508) 			err = -EEXIST;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 509) 			if (ext2_match (namelen, name, de))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 510) 				goto out_unlock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 511) 			name_len = EXT2_DIR_REC_LEN(de->name_len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 512) 			rec_len = ext2_rec_len_from_disk(de->rec_len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 513) 			if (!de->inode && rec_len >= reclen)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 514) 				goto got_it;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 515) 			if (rec_len >= name_len + reclen)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 516) 				goto got_it;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 517) 			de = (ext2_dirent *) ((char *) de + rec_len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 518) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 519) 		unlock_page(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 520) 		ext2_put_page(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 521) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 522) 	BUG();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 523) 	return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 524) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 525) got_it:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 526) 	pos = page_offset(page) +
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 527) 		(char*)de - (char*)page_address(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 528) 	err = ext2_prepare_chunk(page, pos, rec_len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 529) 	if (err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 530) 		goto out_unlock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 531) 	if (de->inode) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 532) 		ext2_dirent *de1 = (ext2_dirent *) ((char *) de + name_len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 533) 		de1->rec_len = ext2_rec_len_to_disk(rec_len - name_len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 534) 		de->rec_len = ext2_rec_len_to_disk(name_len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 535) 		de = de1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 536) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 537) 	de->name_len = namelen;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 538) 	memcpy(de->name, name, namelen);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 539) 	de->inode = cpu_to_le32(inode->i_ino);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 540) 	ext2_set_de_type (de, inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 541) 	err = ext2_commit_chunk(page, pos, rec_len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 542) 	dir->i_mtime = dir->i_ctime = current_time(dir);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 543) 	EXT2_I(dir)->i_flags &= ~EXT2_BTREE_FL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 544) 	mark_inode_dirty(dir);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 545) 	/* OFFSET_CACHE */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 546) out_put:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 547) 	ext2_put_page(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 548) out:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 549) 	return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 550) out_unlock:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 551) 	unlock_page(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 552) 	goto out_put;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 553) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 554) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 555) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 556)  * ext2_delete_entry deletes a directory entry by merging it with the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 557)  * previous entry. Page is up-to-date. Releases the page.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 558)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 559) int ext2_delete_entry (struct ext2_dir_entry_2 * dir, struct page * page )
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 560) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 561) 	struct inode *inode = page->mapping->host;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 562) 	char *kaddr = page_address(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 563) 	unsigned from = ((char*)dir - kaddr) & ~(ext2_chunk_size(inode)-1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 564) 	unsigned to = ((char *)dir - kaddr) +
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 565) 				ext2_rec_len_from_disk(dir->rec_len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 566) 	loff_t pos;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 567) 	ext2_dirent * pde = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 568) 	ext2_dirent * de = (ext2_dirent *) (kaddr + from);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 569) 	int err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 570) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 571) 	while ((char*)de < (char*)dir) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 572) 		if (de->rec_len == 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 573) 			ext2_error(inode->i_sb, __func__,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 574) 				"zero-length directory entry");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 575) 			err = -EIO;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 576) 			goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 577) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 578) 		pde = de;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 579) 		de = ext2_next_entry(de);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 580) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 581) 	if (pde)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 582) 		from = (char*)pde - (char*)page_address(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 583) 	pos = page_offset(page) + from;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 584) 	lock_page(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 585) 	err = ext2_prepare_chunk(page, pos, to - from);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 586) 	BUG_ON(err);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 587) 	if (pde)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 588) 		pde->rec_len = ext2_rec_len_to_disk(to - from);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 589) 	dir->inode = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 590) 	err = ext2_commit_chunk(page, pos, to - from);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 591) 	inode->i_ctime = inode->i_mtime = current_time(inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 592) 	EXT2_I(inode)->i_flags &= ~EXT2_BTREE_FL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 593) 	mark_inode_dirty(inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 594) out:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 595) 	ext2_put_page(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 596) 	return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 597) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 598) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 599) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 600)  * Set the first fragment of directory.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 601)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 602) int ext2_make_empty(struct inode *inode, struct inode *parent)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 603) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 604) 	struct page *page = grab_cache_page(inode->i_mapping, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 605) 	unsigned chunk_size = ext2_chunk_size(inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 606) 	struct ext2_dir_entry_2 * de;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 607) 	int err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 608) 	void *kaddr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 609) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 610) 	if (!page)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 611) 		return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 612) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 613) 	err = ext2_prepare_chunk(page, 0, chunk_size);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 614) 	if (err) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 615) 		unlock_page(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 616) 		goto fail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 617) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 618) 	kaddr = kmap_atomic(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 619) 	memset(kaddr, 0, chunk_size);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 620) 	de = (struct ext2_dir_entry_2 *)kaddr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 621) 	de->name_len = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 622) 	de->rec_len = ext2_rec_len_to_disk(EXT2_DIR_REC_LEN(1));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 623) 	memcpy (de->name, ".\0\0", 4);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 624) 	de->inode = cpu_to_le32(inode->i_ino);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 625) 	ext2_set_de_type (de, inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 626) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 627) 	de = (struct ext2_dir_entry_2 *)(kaddr + EXT2_DIR_REC_LEN(1));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 628) 	de->name_len = 2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 629) 	de->rec_len = ext2_rec_len_to_disk(chunk_size - EXT2_DIR_REC_LEN(1));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 630) 	de->inode = cpu_to_le32(parent->i_ino);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 631) 	memcpy (de->name, "..\0", 4);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 632) 	ext2_set_de_type (de, inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 633) 	kunmap_atomic(kaddr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 634) 	err = ext2_commit_chunk(page, 0, chunk_size);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 635) fail:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 636) 	put_page(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 637) 	return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 638) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 639) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 640) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 641)  * routine to check that the specified directory is empty (for rmdir)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 642)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 643) int ext2_empty_dir (struct inode * inode)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 644) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 645) 	struct page *page = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 646) 	unsigned long i, npages = dir_pages(inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 647) 	int dir_has_error = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 648) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 649) 	for (i = 0; i < npages; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 650) 		char *kaddr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 651) 		ext2_dirent * de;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 652) 		page = ext2_get_page(inode, i, dir_has_error);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 653) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 654) 		if (IS_ERR(page)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 655) 			dir_has_error = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 656) 			continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 657) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 658) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 659) 		kaddr = page_address(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 660) 		de = (ext2_dirent *)kaddr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 661) 		kaddr += ext2_last_byte(inode, i) - EXT2_DIR_REC_LEN(1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 662) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 663) 		while ((char *)de <= kaddr) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 664) 			if (de->rec_len == 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 665) 				ext2_error(inode->i_sb, __func__,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 666) 					"zero-length directory entry");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 667) 				printk("kaddr=%p, de=%p\n", kaddr, de);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 668) 				goto not_empty;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 669) 			}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 670) 			if (de->inode != 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 671) 				/* check for . and .. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 672) 				if (de->name[0] != '.')
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 673) 					goto not_empty;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 674) 				if (de->name_len > 2)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 675) 					goto not_empty;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 676) 				if (de->name_len < 2) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 677) 					if (de->inode !=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 678) 					    cpu_to_le32(inode->i_ino))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 679) 						goto not_empty;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 680) 				} else if (de->name[1] != '.')
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 681) 					goto not_empty;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 682) 			}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 683) 			de = ext2_next_entry(de);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 684) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 685) 		ext2_put_page(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 686) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 687) 	return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 688) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 689) not_empty:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 690) 	ext2_put_page(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 691) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 692) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 693) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 694) const struct file_operations ext2_dir_operations = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 695) 	.llseek		= generic_file_llseek,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 696) 	.read		= generic_read_dir,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 697) 	.iterate_shared	= ext2_readdir,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 698) 	.unlocked_ioctl = ext2_ioctl,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 699) #ifdef CONFIG_COMPAT
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 700) 	.compat_ioctl	= ext2_compat_ioctl,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 701) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 702) 	.fsync		= ext2_fsync,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 703) };