mirror of
https://github.com/FEX-Emu/linux.git
synced 2024-12-27 03:47:43 +00:00
5ca2960733
When the exportfs interface was added the expectation was that filesystems provide an operation to convert from a file handle to an inode/dentry, but it kept a backwards compat option that still calls into iget. Calling into iget from non-filesystem code is very bad, because it gives too little information to filesystem, and simply crashes if the filesystem doesn't implement the ->read_inode routine. Fortunately there are only two filesystems left using this fallback: efs and jfs. This patch moves a copy of export_iget to each of those to implement the get_dentry method. While this is a temporary increase of lines of code in the kernel it allows for a much cleaner interface and important code restructuring in later patches. [akpm@linux-foundation.org: add jfs_get_inode_flags() declaration] Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
143 lines
2.9 KiB
C
143 lines
2.9 KiB
C
/*
|
|
* namei.c
|
|
*
|
|
* Copyright (c) 1999 Al Smith
|
|
*
|
|
* Portions derived from work (c) 1995,1996 Christian Vogelgsang.
|
|
*/
|
|
|
|
#include <linux/buffer_head.h>
|
|
#include <linux/string.h>
|
|
#include <linux/efs_fs.h>
|
|
#include <linux/smp_lock.h>
|
|
|
|
static efs_ino_t efs_find_entry(struct inode *inode, const char *name, int len) {
|
|
struct buffer_head *bh;
|
|
|
|
int slot, namelen;
|
|
char *nameptr;
|
|
struct efs_dir *dirblock;
|
|
struct efs_dentry *dirslot;
|
|
efs_ino_t inodenum;
|
|
efs_block_t block;
|
|
|
|
if (inode->i_size & (EFS_DIRBSIZE-1))
|
|
printk(KERN_WARNING "EFS: WARNING: find_entry(): directory size not a multiple of EFS_DIRBSIZE\n");
|
|
|
|
for(block = 0; block < inode->i_blocks; block++) {
|
|
|
|
bh = sb_bread(inode->i_sb, efs_bmap(inode, block));
|
|
if (!bh) {
|
|
printk(KERN_ERR "EFS: find_entry(): failed to read dir block %d\n", block);
|
|
return 0;
|
|
}
|
|
|
|
dirblock = (struct efs_dir *) bh->b_data;
|
|
|
|
if (be16_to_cpu(dirblock->magic) != EFS_DIRBLK_MAGIC) {
|
|
printk(KERN_ERR "EFS: find_entry(): invalid directory block\n");
|
|
brelse(bh);
|
|
return(0);
|
|
}
|
|
|
|
for(slot = 0; slot < dirblock->slots; slot++) {
|
|
dirslot = (struct efs_dentry *) (((char *) bh->b_data) + EFS_SLOTAT(dirblock, slot));
|
|
|
|
namelen = dirslot->namelen;
|
|
nameptr = dirslot->name;
|
|
|
|
if ((namelen == len) && (!memcmp(name, nameptr, len))) {
|
|
inodenum = be32_to_cpu(dirslot->inode);
|
|
brelse(bh);
|
|
return(inodenum);
|
|
}
|
|
}
|
|
brelse(bh);
|
|
}
|
|
return(0);
|
|
}
|
|
|
|
struct dentry *efs_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd) {
|
|
efs_ino_t inodenum;
|
|
struct inode * inode = NULL;
|
|
|
|
lock_kernel();
|
|
inodenum = efs_find_entry(dir, dentry->d_name.name, dentry->d_name.len);
|
|
if (inodenum) {
|
|
if (!(inode = iget(dir->i_sb, inodenum))) {
|
|
unlock_kernel();
|
|
return ERR_PTR(-EACCES);
|
|
}
|
|
}
|
|
unlock_kernel();
|
|
|
|
d_add(dentry, inode);
|
|
return NULL;
|
|
}
|
|
|
|
struct dentry *efs_get_dentry(struct super_block *sb, void *vobjp)
|
|
{
|
|
__u32 *objp = vobjp;
|
|
unsigned long ino = objp[0];
|
|
__u32 generation = objp[1];
|
|
struct inode *inode;
|
|
struct dentry *result;
|
|
|
|
if (ino == 0)
|
|
return ERR_PTR(-ESTALE);
|
|
inode = iget(sb, ino);
|
|
if (inode == NULL)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
if (is_bad_inode(inode) ||
|
|
(generation && inode->i_generation != generation)) {
|
|
result = ERR_PTR(-ESTALE);
|
|
goto out_iput;
|
|
}
|
|
|
|
result = d_alloc_anon(inode);
|
|
if (!result) {
|
|
result = ERR_PTR(-ENOMEM);
|
|
goto out_iput;
|
|
}
|
|
return result;
|
|
|
|
out_iput:
|
|
iput(inode);
|
|
return result;
|
|
}
|
|
|
|
struct dentry *efs_get_parent(struct dentry *child)
|
|
{
|
|
struct dentry *parent;
|
|
struct inode *inode;
|
|
efs_ino_t ino;
|
|
int error;
|
|
|
|
lock_kernel();
|
|
|
|
error = -ENOENT;
|
|
ino = efs_find_entry(child->d_inode, "..", 2);
|
|
if (!ino)
|
|
goto fail;
|
|
|
|
error = -EACCES;
|
|
inode = iget(child->d_inode->i_sb, ino);
|
|
if (!inode)
|
|
goto fail;
|
|
|
|
error = -ENOMEM;
|
|
parent = d_alloc_anon(inode);
|
|
if (!parent)
|
|
goto fail_iput;
|
|
|
|
unlock_kernel();
|
|
return parent;
|
|
|
|
fail_iput:
|
|
iput(inode);
|
|
fail:
|
|
unlock_kernel();
|
|
return ERR_PTR(error);
|
|
}
|