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120 lines
2.7 KiB
120 lines
2.7 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* |
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* namei.c |
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* |
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* Copyright (c) 1999 Al Smith |
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* |
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* Portions derived from work (c) 1995,1996 Christian Vogelgsang. |
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*/ |
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#include <linux/buffer_head.h> |
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#include <linux/string.h> |
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#include <linux/exportfs.h> |
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#include "efs.h" |
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static efs_ino_t efs_find_entry(struct inode *inode, const char *name, int len) |
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{ |
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struct buffer_head *bh; |
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int slot, namelen; |
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char *nameptr; |
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struct efs_dir *dirblock; |
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struct efs_dentry *dirslot; |
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efs_ino_t inodenum; |
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efs_block_t block; |
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if (inode->i_size & (EFS_DIRBSIZE-1)) |
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pr_warn("%s(): directory size not a multiple of EFS_DIRBSIZE\n", |
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__func__); |
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for(block = 0; block < inode->i_blocks; block++) { |
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bh = sb_bread(inode->i_sb, efs_bmap(inode, block)); |
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if (!bh) { |
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pr_err("%s(): failed to read dir block %d\n", |
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__func__, block); |
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return 0; |
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} |
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dirblock = (struct efs_dir *) bh->b_data; |
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if (be16_to_cpu(dirblock->magic) != EFS_DIRBLK_MAGIC) { |
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pr_err("%s(): invalid directory block\n", __func__); |
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brelse(bh); |
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return 0; |
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} |
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for (slot = 0; slot < dirblock->slots; slot++) { |
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dirslot = (struct efs_dentry *) (((char *) bh->b_data) + EFS_SLOTAT(dirblock, slot)); |
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namelen = dirslot->namelen; |
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nameptr = dirslot->name; |
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if ((namelen == len) && (!memcmp(name, nameptr, len))) { |
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inodenum = be32_to_cpu(dirslot->inode); |
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brelse(bh); |
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return inodenum; |
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} |
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} |
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brelse(bh); |
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} |
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return 0; |
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} |
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struct dentry *efs_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) |
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{ |
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efs_ino_t inodenum; |
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struct inode *inode = NULL; |
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inodenum = efs_find_entry(dir, dentry->d_name.name, dentry->d_name.len); |
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if (inodenum) |
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inode = efs_iget(dir->i_sb, inodenum); |
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return d_splice_alias(inode, dentry); |
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} |
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static struct inode *efs_nfs_get_inode(struct super_block *sb, u64 ino, |
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u32 generation) |
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{ |
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struct inode *inode; |
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if (ino == 0) |
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return ERR_PTR(-ESTALE); |
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inode = efs_iget(sb, ino); |
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if (IS_ERR(inode)) |
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return ERR_CAST(inode); |
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if (generation && inode->i_generation != generation) { |
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iput(inode); |
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return ERR_PTR(-ESTALE); |
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} |
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return inode; |
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} |
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struct dentry *efs_fh_to_dentry(struct super_block *sb, struct fid *fid, |
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int fh_len, int fh_type) |
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{ |
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return generic_fh_to_dentry(sb, fid, fh_len, fh_type, |
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efs_nfs_get_inode); |
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} |
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struct dentry *efs_fh_to_parent(struct super_block *sb, struct fid *fid, |
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int fh_len, int fh_type) |
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{ |
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return generic_fh_to_parent(sb, fid, fh_len, fh_type, |
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efs_nfs_get_inode); |
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} |
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struct dentry *efs_get_parent(struct dentry *child) |
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{ |
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struct dentry *parent = ERR_PTR(-ENOENT); |
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efs_ino_t ino; |
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ino = efs_find_entry(d_inode(child), "..", 2); |
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if (ino) |
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parent = d_obtain_alias(efs_iget(child->d_sb, ino)); |
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return parent; |
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}
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