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- /*
- * linux/fs/ext2/inode.c
- *
- * Copyright (C) 1992, 1993, 1994 Remy Card (card@masi.ibp.fr)
- * Laboratoire MASI - Institut Blaise Pascal
- * Universite Pierre et Marie Curie (Paris VI)
- *
- * from
- *
- * linux/fs/minix/inode.c
- *
- * Copyright (C) 1991, 1992 Linus Torvalds
- *
- * Goal-directed block allocation by Stephen Tweedie (sct@dcs.ed.ac.uk), 1993
- */
-
- #include <asm/segment.h>
- #include <asm/system.h>
-
- #include <linux/errno.h>
- #include <linux/fs.h>
- #include <linux/ext2_fs.h>
- #include <linux/sched.h>
- #include <linux/stat.h>
- #include <linux/string.h>
- #include <linux/locks.h>
-
- #define clear_block(addr,size) \
- __asm__("cld\n\t" \
- "rep\n\t" \
- "stosl" \
- : \
- :"a" (0), "c" (size / 4), "D" ((long) (addr)) \
- :"cx", "di")
-
- void ext2_put_inode (struct inode * inode)
- {
- ext2_discard_prealloc (inode);
- if (inode->i_nlink || inode->i_ino == EXT2_ACL_IDX_INO ||
- inode->i_ino == EXT2_ACL_DATA_INO)
- return;
- inode->i_size = 0;
- if (inode->i_blocks)
- ext2_truncate (inode);
- ext2_free_inode (inode);
- }
-
- #define inode_bmap(inode, nr) ((inode)->u.ext2_i.i_data[(nr)])
-
- static int block_bmap (struct buffer_head * bh, int nr)
- {
- int tmp;
-
- if (!bh)
- return 0;
- tmp = ((unsigned long *) bh->b_data)[nr];
- brelse (bh);
- return tmp;
- }
-
- /*
- * ext2_discard_prealloc and ext2_alloc_block are atomic wrt. the
- * superblock in the same manner as are ext2_free_blocks and
- * ext2_new_block. We just wait on the super rather than locking it
- * here, since ext2_new_block will do the necessary locking and we
- * can't block until then.
- */
- void ext2_discard_prealloc (struct inode * inode)
- {
- #ifdef EXT2_PREALLOCATE
- if (inode->u.ext2_i.i_prealloc_count) {
- int i = inode->u.ext2_i.i_prealloc_count;
- inode->u.ext2_i.i_prealloc_count = 0;
- ext2_free_blocks (inode->i_sb,
- inode->u.ext2_i.i_prealloc_block,
- i);
- }
- #endif
- }
-
- static int ext2_alloc_block (struct inode * inode, unsigned long goal)
- {
- #ifdef EXT2FS_DEBUG
- static unsigned long alloc_hits = 0, alloc_attempts = 0;
- #endif
- unsigned long result;
- struct buffer_head * bh;
-
- wait_on_super (inode->i_sb);
-
- #ifdef EXT2_PREALLOCATE
- if (inode->u.ext2_i.i_prealloc_count &&
- (goal == inode->u.ext2_i.i_prealloc_block ||
- goal + 1 == inode->u.ext2_i.i_prealloc_block))
- {
- result = inode->u.ext2_i.i_prealloc_block++;
- inode->u.ext2_i.i_prealloc_count--;
- ext2_debug ("preallocation hit (%lu/%lu).\n",
- ++alloc_hits, ++alloc_attempts);
-
- /* It doesn't matter if we block in getblk() since
- we have already atomically allocated the block, and
- are only clearing it now. */
- if (!(bh = getblk (inode->i_sb->s_dev, result,
- inode->i_sb->s_blocksize))) {
- ext2_error (inode->i_sb, "ext2_alloc_block",
- "cannot get block %lu", result);
- return 0;
- }
- clear_block (bh->b_data, inode->i_sb->s_blocksize);
- bh->b_uptodate = 1;
- bh->b_dirt = 1;
- brelse (bh);
- } else {
- ext2_discard_prealloc (inode);
- ext2_debug ("preallocation miss (%lu/%lu).\n",
- alloc_hits, ++alloc_attempts);
- if (S_ISREG(inode->i_mode))
- result = ext2_new_block
- (inode->i_sb, goal,
- &inode->u.ext2_i.i_prealloc_count,
- &inode->u.ext2_i.i_prealloc_block);
- else
- result = ext2_new_block (inode->i_sb, goal, 0, 0);
- }
- #else
- result = ext2_new_block (inode->i_sb, goal, 0, 0);
- #endif
-
- return result;
- }
-
-
- int ext2_bmap (struct inode * inode, int block)
- {
- int i;
- int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb);
-
- if (block < 0) {
- ext2_warning (inode->i_sb, "ext2_bmap", "block < 0");
- return 0;
- }
- if (block >= EXT2_NDIR_BLOCKS + addr_per_block +
- addr_per_block * addr_per_block +
- addr_per_block * addr_per_block * addr_per_block) {
- ext2_warning (inode->i_sb, "ext2_bmap", "block > big");
- return 0;
- }
- if (block < EXT2_NDIR_BLOCKS)
- return inode_bmap (inode, block);
- block -= EXT2_NDIR_BLOCKS;
- if (block < addr_per_block) {
- i = inode_bmap (inode, EXT2_IND_BLOCK);
- if (!i)
- return 0;
- return block_bmap (bread (inode->i_dev, i,
- inode->i_sb->s_blocksize), block);
- }
- block -= addr_per_block;
- if (block < addr_per_block * addr_per_block) {
- i = inode_bmap (inode, EXT2_DIND_BLOCK);
- if (!i)
- return 0;
- i = block_bmap (bread (inode->i_dev, i,
- inode->i_sb->s_blocksize),
- block / addr_per_block);
- if (!i)
- return 0;
- return block_bmap (bread (inode->i_dev, i,
- inode->i_sb->s_blocksize),
- block & (addr_per_block - 1));
- }
- block -= addr_per_block * addr_per_block;
- i = inode_bmap (inode, EXT2_TIND_BLOCK);
- if (!i)
- return 0;
- i = block_bmap (bread (inode->i_dev, i, inode->i_sb->s_blocksize),
- block / (addr_per_block * addr_per_block));
- if (!i)
- return 0;
- i = block_bmap (bread (inode->i_dev, i, inode->i_sb->s_blocksize),
- (block / addr_per_block) & (addr_per_block - 1));
- if (!i)
- return 0;
- return block_bmap (bread (inode->i_dev, i, inode->i_sb->s_blocksize),
- block & (addr_per_block - 1));
- }
-
- static struct buffer_head * inode_getblk (struct inode * inode, int nr,
- int create, int new_block, int * err)
- {
- int tmp, goal = 0;
- unsigned long * p;
- struct buffer_head * result;
- int blocks = inode->i_sb->s_blocksize / 512;
-
- p = inode->u.ext2_i.i_data + nr;
- repeat:
- tmp = *p;
- if (tmp) {
- result = getblk (inode->i_dev, tmp, inode->i_sb->s_blocksize);
- if (tmp == *p)
- return result;
- brelse (result);
- goto repeat;
- }
- if (!create || new_block >=
- (current->rlim[RLIMIT_FSIZE].rlim_cur >>
- EXT2_BLOCK_SIZE_BITS(inode->i_sb))) {
- *err = -EFBIG;
- return NULL;
- }
- if (inode->u.ext2_i.i_next_alloc_block == new_block)
- goal = inode->u.ext2_i.i_next_alloc_goal;
-
- ext2_debug ("hint = %d,", goal);
-
- if (!goal) {
- for (tmp = nr - 1; tmp >= 0; tmp--) {
- if (inode->u.ext2_i.i_data[tmp]) {
- goal = inode->u.ext2_i.i_data[tmp];
- break;
- }
- }
- if (!goal)
- goal = (inode->u.ext2_i.i_block_group *
- EXT2_BLOCKS_PER_GROUP(inode->i_sb)) +
- inode->i_sb->u.ext2_sb.s_es->s_first_data_block;
- }
-
- ext2_debug ("goal = %d.\n", goal);
-
- tmp = ext2_alloc_block (inode, goal);
- if (!tmp)
- return NULL;
- result = getblk (inode->i_dev, tmp, inode->i_sb->s_blocksize);
- if (*p) {
- ext2_free_blocks (inode->i_sb, tmp, 1);
- brelse (result);
- goto repeat;
- }
- *p = tmp;
- inode->u.ext2_i.i_next_alloc_block = new_block;
- inode->u.ext2_i.i_next_alloc_goal = tmp;
- inode->i_ctime = CURRENT_TIME;
- inode->i_blocks += blocks;
- if (IS_SYNC(inode))
- ext2_sync_inode (inode);
- else
- inode->i_dirt = 1;
- return result;
- }
-
- static struct buffer_head * block_getblk (struct inode * inode,
- struct buffer_head * bh, int nr,
- int create, int blocksize,
- int new_block, int * err)
- {
- int tmp, goal = 0;
- unsigned long * p;
- struct buffer_head * result;
- int blocks = inode->i_sb->s_blocksize / 512;
-
- if (!bh)
- return NULL;
- if (!bh->b_uptodate) {
- ll_rw_block (READ, 1, &bh);
- wait_on_buffer (bh);
- if (!bh->b_uptodate) {
- brelse (bh);
- return NULL;
- }
- }
- p = (unsigned long *) bh->b_data + nr;
- repeat:
- tmp = *p;
- if (tmp) {
- result = getblk (bh->b_dev, tmp, blocksize);
- if (tmp == *p) {
- brelse (bh);
- return result;
- }
- brelse (result);
- goto repeat;
- }
- if (!create || new_block >=
- (current->rlim[RLIMIT_FSIZE].rlim_cur >>
- EXT2_BLOCK_SIZE_BITS(inode->i_sb))) {
- brelse (bh);
- *err = -EFBIG;
- return NULL;
- }
- if (inode->u.ext2_i.i_next_alloc_block == new_block)
- goal = inode->u.ext2_i.i_next_alloc_goal;
- if (!goal) {
- for (tmp = nr - 1; tmp >= 0; tmp--) {
- if (((unsigned long *) bh->b_data)[tmp]) {
- goal = ((unsigned long *)bh->b_data)[tmp];
- break;
- }
- }
- if (!goal)
- goal = bh->b_blocknr;
- }
- tmp = ext2_alloc_block (inode, goal);
- if (!tmp) {
- brelse (bh);
- return NULL;
- }
- result = getblk (bh->b_dev, tmp, blocksize);
- if (*p) {
- ext2_free_blocks (inode->i_sb, tmp, 1);
- brelse (result);
- goto repeat;
- }
- *p = tmp;
- bh->b_dirt = 1;
- if (IS_SYNC(inode)) {
- ll_rw_block (WRITE, 1, &bh);
- wait_on_buffer (bh);
- }
- inode->i_ctime = CURRENT_TIME;
- inode->i_blocks += blocks;
- inode->i_dirt = 1;
- inode->u.ext2_i.i_next_alloc_block = new_block;
- inode->u.ext2_i.i_next_alloc_goal = tmp;
- brelse (bh);
- return result;
- }
-
- struct buffer_head * ext2_getblk (struct inode * inode, long block,
- int create, int * err)
- {
- struct buffer_head * bh;
- unsigned long b;
- unsigned long addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb);
-
- *err = -EIO;
- if (block < 0) {
- ext2_warning (inode->i_sb, "ext2_getblk", "block < 0");
- return NULL;
- }
- if (block > EXT2_NDIR_BLOCKS + addr_per_block +
- addr_per_block * addr_per_block +
- addr_per_block * addr_per_block * addr_per_block) {
- ext2_warning (inode->i_sb, "ext2_getblk", "block > big");
- return NULL;
- }
- /*
- * If this is a sequential block allocation, set the next_alloc_block
- * to this block now so that all the indblock and data block
- * allocations use the same goal zone
- */
-
- ext2_debug ("block %lu, next %lu, goal %lu.\n", block,
- inode->u.ext2_i.i_next_alloc_block,
- inode->u.ext2_i.i_next_alloc_goal);
-
- if (block == inode->u.ext2_i.i_next_alloc_block + 1) {
- inode->u.ext2_i.i_next_alloc_block++;
- inode->u.ext2_i.i_next_alloc_goal++;
- }
-
- *err = -ENOSPC;
- b = block;
- if (block < EXT2_NDIR_BLOCKS)
- return inode_getblk (inode, block, create, b, err);
- block -= EXT2_NDIR_BLOCKS;
- if (block < addr_per_block) {
- bh = inode_getblk (inode, EXT2_IND_BLOCK, create, b, err);
- return block_getblk (inode, bh, block, create,
- inode->i_sb->s_blocksize, b, err);
- }
- block -= addr_per_block;
- if (block < addr_per_block * addr_per_block) {
- bh = inode_getblk (inode, EXT2_DIND_BLOCK, create, b, err);
- bh = block_getblk (inode, bh, block / addr_per_block, create,
- inode->i_sb->s_blocksize, b, err);
- return block_getblk (inode, bh, block & (addr_per_block - 1),
- create, inode->i_sb->s_blocksize, b, err);
- }
- block -= addr_per_block * addr_per_block;
- bh = inode_getblk (inode, EXT2_TIND_BLOCK, create, b, err);
- bh = block_getblk (inode, bh, block/(addr_per_block * addr_per_block),
- create, inode->i_sb->s_blocksize, b, err);
- bh = block_getblk (inode, bh, (block/addr_per_block) & (addr_per_block - 1),
- create, inode->i_sb->s_blocksize, b, err);
- return block_getblk (inode, bh, block & (addr_per_block - 1), create,
- inode->i_sb->s_blocksize, b, err);
- }
-
- struct buffer_head * ext2_bread (struct inode * inode, int block,
- int create, int *err)
- {
- struct buffer_head * bh;
-
- bh = ext2_getblk (inode, block, create, err);
- if (!bh || bh->b_uptodate)
- return bh;
- ll_rw_block (READ, 1, &bh);
- wait_on_buffer (bh);
- if (bh->b_uptodate)
- return bh;
- brelse (bh);
- *err = -EIO;
- return NULL;
- }
-
- void ext2_read_inode (struct inode * inode)
- {
- struct buffer_head * bh;
- struct ext2_inode * raw_inode;
- unsigned long block_group;
- unsigned long group_desc;
- unsigned long desc;
- unsigned long block;
- struct ext2_group_desc * gdp;
-
- if ((inode->i_ino != EXT2_ROOT_INO && inode->i_ino != EXT2_ACL_IDX_INO &&
- inode->i_ino != EXT2_ACL_DATA_INO && inode->i_ino < EXT2_FIRST_INO) ||
- inode->i_ino > inode->i_sb->u.ext2_sb.s_es->s_inodes_count) {
- ext2_error (inode->i_sb, "ext2_read_inode",
- "bad inode number: %lu", inode->i_ino);
- return;
- }
- block_group = (inode->i_ino - 1) / EXT2_INODES_PER_GROUP(inode->i_sb);
- if (block_group >= inode->i_sb->u.ext2_sb.s_groups_count)
- ext2_panic (inode->i_sb, "ext2_read_inode",
- "group >= groups count");
- group_desc = block_group / EXT2_DESC_PER_BLOCK(inode->i_sb);
- desc = block_group % EXT2_DESC_PER_BLOCK(inode->i_sb);
- bh = inode->i_sb->u.ext2_sb.s_group_desc[group_desc];
- if (!bh)
- ext2_panic (inode->i_sb, "ext2_read_inode",
- "Descriptor not loaded");
- gdp = (struct ext2_group_desc *) bh->b_data;
- block = gdp[desc].bg_inode_table +
- (((inode->i_ino - 1) % EXT2_INODES_PER_GROUP(inode->i_sb))
- / EXT2_INODES_PER_BLOCK(inode->i_sb));
- if (!(bh = bread (inode->i_dev, block, inode->i_sb->s_blocksize)))
- ext2_panic (inode->i_sb, "ext2_read_inode",
- "unable to read i-node block\n"
- "inode=%lu, block=%lu", inode->i_ino, block);
- raw_inode = ((struct ext2_inode *) bh->b_data) +
- (inode->i_ino - 1) % EXT2_INODES_PER_BLOCK(inode->i_sb);
- inode->i_mode = raw_inode->i_mode;
- inode->i_uid = raw_inode->i_uid;
- inode->i_gid = raw_inode->i_gid;
- inode->i_nlink = raw_inode->i_links_count;
- inode->i_size = raw_inode->i_size;
- inode->i_atime = raw_inode->i_atime;
- inode->i_ctime = raw_inode->i_ctime;
- inode->i_mtime = raw_inode->i_mtime;
- inode->u.ext2_i.i_dtime = raw_inode->i_dtime;
- inode->i_blksize = inode->i_sb->s_blocksize;
- inode->i_blocks = raw_inode->i_blocks;
- inode->u.ext2_i.i_flags = raw_inode->i_flags;
- inode->u.ext2_i.i_faddr = raw_inode->i_faddr;
- inode->u.ext2_i.i_frag = raw_inode->i_frag;
- inode->u.ext2_i.i_fsize = raw_inode->i_fsize;
- inode->u.ext2_i.i_file_acl = raw_inode->i_file_acl;
- inode->u.ext2_i.i_dir_acl = raw_inode->i_dir_acl;
- inode->u.ext2_i.i_version = raw_inode->i_version;
- inode->u.ext2_i.i_block_group = block_group;
- inode->u.ext2_i.i_next_alloc_block = 0;
- inode->u.ext2_i.i_next_alloc_goal = 0;
- if (inode->u.ext2_i.i_prealloc_count)
- ext2_error (inode->i_sb, "ext2_read_inode",
- "New inode has non-zero prealloc count!");
- if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
- inode->i_rdev = raw_inode->i_block[0];
- else for (block = 0; block < EXT2_N_BLOCKS; block++)
- inode->u.ext2_i.i_data[block] = raw_inode->i_block[block];
- brelse (bh);
- inode->i_op = NULL;
- if (inode->i_ino == EXT2_ACL_IDX_INO ||
- inode->i_ino == EXT2_ACL_DATA_INO)
- /* Nothing to do */ ;
- else if (S_ISREG(inode->i_mode))
- inode->i_op = &ext2_file_inode_operations;
- else if (S_ISDIR(inode->i_mode))
- inode->i_op = &ext2_dir_inode_operations;
- else if (S_ISLNK(inode->i_mode))
- inode->i_op = &ext2_symlink_inode_operations;
- else if (S_ISCHR(inode->i_mode))
- inode->i_op = &chrdev_inode_operations;
- else if (S_ISBLK(inode->i_mode))
- inode->i_op = &blkdev_inode_operations;
- else if (S_ISFIFO(inode->i_mode))
- init_fifo(inode);
- if (inode->u.ext2_i.i_flags & EXT2_SYNC_FL)
- inode->i_flags |= MS_SYNC;
- }
-
- static struct buffer_head * ext2_update_inode (struct inode * inode)
- {
- struct buffer_head * bh;
- struct ext2_inode * raw_inode;
- unsigned long block_group;
- unsigned long group_desc;
- unsigned long desc;
- unsigned long block;
- struct ext2_group_desc * gdp;
-
- if ((inode->i_ino != EXT2_ROOT_INO && inode->i_ino < EXT2_FIRST_INO) ||
- inode->i_ino > inode->i_sb->u.ext2_sb.s_es->s_inodes_count) {
- ext2_error (inode->i_sb, "ext2_write_inode",
- "bad inode number: %lu", inode->i_ino);
- return 0;
- }
- block_group = (inode->i_ino - 1) / EXT2_INODES_PER_GROUP(inode->i_sb);
- if (block_group >= inode->i_sb->u.ext2_sb.s_groups_count)
- ext2_panic (inode->i_sb, "ext2_write_inode",
- "group >= groups count");
- group_desc = block_group / EXT2_DESC_PER_BLOCK(inode->i_sb);
- desc = block_group % EXT2_DESC_PER_BLOCK(inode->i_sb);
- bh = inode->i_sb->u.ext2_sb.s_group_desc[group_desc];
- if (!bh)
- ext2_panic (inode->i_sb, "ext2_write_inode",
- "Descriptor not loaded");
- gdp = (struct ext2_group_desc *) bh->b_data;
- block = gdp[desc].bg_inode_table +
- (((inode->i_ino - 1) % EXT2_INODES_PER_GROUP(inode->i_sb))
- / EXT2_INODES_PER_BLOCK(inode->i_sb));
- if (!(bh = bread (inode->i_dev, block, inode->i_sb->s_blocksize)))
- ext2_panic (inode->i_sb, "ext2_write_inode",
- "unable to read i-node block\n"
- "inode=%lu, block=%lu", inode->i_ino, block);
- raw_inode = ((struct ext2_inode *)bh->b_data) +
- (inode->i_ino - 1) % EXT2_INODES_PER_BLOCK(inode->i_sb);
- raw_inode->i_mode = inode->i_mode;
- raw_inode->i_uid = inode->i_uid;
- raw_inode->i_gid = inode->i_gid;
- raw_inode->i_links_count = inode->i_nlink;
- raw_inode->i_size = inode->i_size;
- raw_inode->i_atime = inode->i_atime;
- raw_inode->i_ctime = inode->i_ctime;
- raw_inode->i_mtime = inode->i_mtime;
- raw_inode->i_blocks = inode->i_blocks;
- raw_inode->i_dtime = inode->u.ext2_i.i_dtime;
- raw_inode->i_flags = inode->u.ext2_i.i_flags;
- raw_inode->i_faddr = inode->u.ext2_i.i_faddr;
- raw_inode->i_frag = inode->u.ext2_i.i_frag;
- raw_inode->i_fsize = inode->u.ext2_i.i_fsize;
- raw_inode->i_file_acl = inode->u.ext2_i.i_file_acl;
- raw_inode->i_dir_acl = inode->u.ext2_i.i_dir_acl;
- raw_inode->i_version = inode->u.ext2_i.i_version;
- if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
- raw_inode->i_block[0] = inode->i_rdev;
- else for (block = 0; block < EXT2_N_BLOCKS; block++)
- raw_inode->i_block[block] = inode->u.ext2_i.i_data[block];
- bh->b_dirt = 1;
- inode->i_dirt = 0;
- return bh;
- }
-
- void ext2_write_inode (struct inode * inode)
- {
- struct buffer_head * bh;
- bh = ext2_update_inode (inode);
- brelse (bh);
- }
-
- int ext2_sync_inode (struct inode *inode)
- {
- int err = 0;
- struct buffer_head *bh;
-
- bh = ext2_update_inode (inode);
- if (bh && bh->b_dirt)
- {
- ll_rw_block (WRITE, 1, &bh);
- wait_on_buffer (bh);
- if (bh->b_req && !bh->b_uptodate)
- {
- printk ("IO error syncing ext2 inode [%04x:%08lx]\n",
- inode->i_dev, inode->i_ino);
- err = -1;
- }
- }
- else if (!bh)
- err = -1;
- brelse (bh);
- return err;
- }
-