476 lines
		
	
	
		
			14 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			476 lines
		
	
	
		
			14 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| #include "fs.h"
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| 
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| #include <stdlib.h>
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| #include <assert.h>
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| 
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| #include "puffs.h"
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| #include "puffs_priv.h"
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| 
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| 
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| /*===========================================================================*
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|  *				fs_trunc				     *
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|  *===========================================================================*/
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| int fs_trunc(ino_t ino_nr, off_t start, off_t end)
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| {
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|   int r;
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|   struct puffs_node *pn;
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|   PUFFS_MAKECRED(pcr, &global_kcred);
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| 
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|   if ((pn = puffs_pn_nodewalk(global_pu, 0, &ino_nr)) == NULL)
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|           return(EINVAL);
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| 
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|   if (end == 0) {
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| 	struct vattr va;
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| 
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| 	if (pn->pn_va.va_size == (u_quad_t) start)
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| 		return(OK);
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| 
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| 	if (global_pu->pu_ops.puffs_node_setattr == NULL)
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| 		return(EINVAL);
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| 	
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| 	puffs_vattr_null(&va);
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| 	va.va_size = start;
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| 
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| 	r = global_pu->pu_ops.puffs_node_setattr(global_pu, pn, &va, pcr);
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| 	if (r) return(EINVAL);
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|   } else {
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| 	/* XXX zerofill the given region. Can we make a hole? */
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| 	off_t bytes_left = end - start;
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| 	char* rw_buf;
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| 
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| 	if (global_pu->pu_ops.puffs_node_write == NULL)
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| 		return(EINVAL);
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| 
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| 	/* XXX split into chunks? */
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| 	rw_buf = malloc(bytes_left);
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| 	if (!rw_buf)
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| 		panic("fs_ftrunc: failed to allocated memory\n");
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| 	memset(rw_buf, 0, bytes_left);
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| 
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| 	r = global_pu->pu_ops.puffs_node_write(global_pu, pn, (uint8_t *)rw_buf,
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| 					start, (size_t *) &bytes_left, pcr, 0);
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| 	free(rw_buf);
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| 	if (r) return(EINVAL);
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|   }
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| 
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|   update_timens(pn, CTIME | MTIME, NULL);
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| 
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|   return(r);
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| }
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| 
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| 
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| /*===========================================================================*
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|  *                              fs_link                                      *
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|  *===========================================================================*/
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| int fs_link(ino_t dir_nr, char *name, ino_t ino_nr)
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| {
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| /* Perform the link(name1, name2) system call. */
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| 
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|   register int r;
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|   struct puffs_node *pn, *pn_dir, *new_pn;
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|   struct timespec cur_time;
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|   struct puffs_kcn pkcnp;
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|   PUFFS_MAKECRED(pcr, &global_kcred);
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|   struct puffs_cn pcn = {&pkcnp, (struct puffs_cred *) __UNCONST(pcr), {0,0,0}};
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| 
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|   if (global_pu->pu_ops.puffs_node_link == NULL)
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|   	return(OK);
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| 
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|   if ((pn = puffs_pn_nodewalk(global_pu, 0, &ino_nr)) == NULL)
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| 	return(EINVAL);
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| 
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|   /* Check to see if the file has maximum number of links already. */
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|   if (pn->pn_va.va_nlink >= LINK_MAX)
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| 	return(EMLINK);
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| 
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|   /* Linking directories is too dangerous to allow. */
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|   if (S_ISDIR(pn->pn_va.va_mode))
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| 	return(EPERM);
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| 
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|   if ((pn_dir = puffs_pn_nodewalk(global_pu, 0, &dir_nr)) == NULL)
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|         return(EINVAL);
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| 
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|   if (pn_dir->pn_va.va_nlink == NO_LINK) {
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| 	/* Dir does not actually exist */
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|         return(ENOENT);
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|   }
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| 
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|   /* If 'name2' exists in full (even if no space) set 'r' to error. */
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|   if ((new_pn = advance(pn_dir, name)) == NULL) {
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|         r = err_code;
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|         if (r == ENOENT) r = OK;
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|   } else {
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|         r = EEXIST;
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|   }
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| 
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|   if (r != OK) return(r);
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| 
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|   /* Try to link. */
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|   pcn.pcn_namelen = strlen(name);
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|   assert(pcn.pcn_namelen <= NAME_MAX);
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|   strcpy(pcn.pcn_name, name);
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| 
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|   if (buildpath) {
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| 	if (puffs_path_pcnbuild(global_pu, &pcn, pn_dir) != 0)
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| 		return(EINVAL);
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|   }
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| 
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|   if (global_pu->pu_ops.puffs_node_link(global_pu, pn_dir, pn, &pcn) != 0)
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| 	r = EINVAL;
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| 
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|   if (buildpath)
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| 	global_pu->pu_pathfree(global_pu, &pcn.pcn_po_full);
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|   
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|   if (r != OK) return(EINVAL);
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| 
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|   (void)clock_time(&cur_time);
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|   update_timens(pn, CTIME, &cur_time);
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|   update_timens(pn_dir, MTIME | CTIME, &cur_time);
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| 
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|   return(OK);
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| }
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| 
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| 
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| /*===========================================================================*
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|  *                             fs_rdlink                                     *
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|  *===========================================================================*/
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| ssize_t fs_rdlink(ino_t ino_nr, struct fsdriver_data *data, size_t bytes)
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| {
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|   register int r;              /* return value */
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|   struct puffs_node *pn;
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|   char path[PATH_MAX];
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|   PUFFS_MAKECRED(pcr, &global_kcred);
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| 
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|   if (bytes > sizeof(path))
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| 	bytes = sizeof(path);
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|   
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|   if ((pn = puffs_pn_nodewalk(global_pu, 0, &ino_nr)) == NULL)
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| 	return(EINVAL);
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| 
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|   if (!S_ISLNK(pn->pn_va.va_mode))
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| 	return(EACCES);
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| 
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|   if (global_pu->pu_ops.puffs_node_readlink == NULL)
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| 	return(EINVAL);
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| 
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|   r = global_pu->pu_ops.puffs_node_readlink(global_pu, pn, pcr, path, &bytes);
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|   if (r != OK) {
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| 	if (r > 0) r = -r;
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| 	return(r);
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|   }
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| 
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|   r = fsdriver_copyout(data, 0, path, bytes);
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| 
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|   return (r == OK) ? bytes : r;
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| }
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| 
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| 
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| /*===========================================================================*
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|  *                              fs_rename                                    *
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|  *===========================================================================*/
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| int fs_rename(ino_t old_dir_nr, char *old_name, ino_t new_dir_nr,
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| 	char *new_name)
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| {
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| /* Perform the rename(name1, name2) system call. */
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|   struct puffs_node *old_dirp, *old_ip;      /* ptrs to old dir, file pnodes */
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|   struct puffs_node *new_dirp, *new_ip;      /* ptrs to new dir, file pnodes */
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|   struct puffs_kcn pkcnp_src;
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|   PUFFS_MAKECRED(pcr_src, &global_kcred);
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|   struct puffs_cn pcn_src = {&pkcnp_src, (struct puffs_cred *) __UNCONST(pcr_src), {0,0,0}};
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|   struct puffs_kcn pkcnp_dest;
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|   PUFFS_MAKECRED(pcr_dest, &global_kcred);
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|   struct puffs_cn pcn_targ = {&pkcnp_dest, (struct puffs_cred *) __UNCONST(pcr_dest), {0,0,0}};
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|   int r = OK;                           /* error flag; initially no error */
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|   int odir, ndir;                       /* TRUE iff {old|new} file is dir */
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|   int same_pdir;                        /* TRUE iff parent dirs are the same */
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|   struct timespec cur_time;
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| 
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|   if (global_pu->pu_ops.puffs_node_rename == NULL)
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| 	return(EINVAL);
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| 
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|   /* Copy the last component of the old name */
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|   pcn_src.pcn_namelen = strlen(old_name);
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|   assert(pcn_src.pcn_namelen <= NAME_MAX);
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|   strcpy(pcn_src.pcn_name, old_name);
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| 
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|   /* Copy the last component of the new name */
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|   pcn_targ.pcn_namelen = strlen(new_name);
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|   assert(pcn_targ.pcn_namelen <= NAME_MAX);
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|   strcpy(pcn_targ.pcn_name, new_name);
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| 
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|   /* Get old dir pnode */
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|   if ((old_dirp = puffs_pn_nodewalk(global_pu, 0, &old_dir_nr)) == NULL)
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|         return(ENOENT);
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| 
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|   old_ip = advance(old_dirp, pcn_src.pcn_name);
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|   if (!old_ip)
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| 	return(err_code);
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| 
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|   if (old_ip->pn_mountpoint)
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| 	return(EBUSY);
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| 
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|   /* Get new dir pnode */
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|   if ((new_dirp = puffs_pn_nodewalk(global_pu, 0, &new_dir_nr)) == NULL) {
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|         return(ENOENT);
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|   } else {
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|         if (new_dirp->pn_va.va_nlink == NO_LINK) {
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| 		/* Dir does not actually exist */
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|                 return(ENOENT);
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|         }
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|   }
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| 
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|   /* not required to exist */
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|   new_ip = advance(new_dirp, pcn_targ.pcn_name);
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| 
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|   /* If the node does exist, make sure it's not a mountpoint. */
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|   if (new_ip != NULL && new_ip->pn_mountpoint)
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| 	return(EBUSY);
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| 
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|   if (old_ip != NULL) {
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| 	/* TRUE iff dir */
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| 	odir = ((old_ip->pn_va.va_mode & I_TYPE) == I_DIRECTORY);
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|   } else {
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| 	odir = FALSE;
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|   }
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| 
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|   /* Check for a variety of possible errors. */
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|   same_pdir = (old_dirp == new_dirp);
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| 
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|   /* Some tests apply only if the new path exists. */
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|   if (new_ip == NULL) {
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| 	if (odir && (new_dirp->pn_va.va_nlink >= SHRT_MAX ||
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| 		     new_dirp->pn_va.va_nlink >= LINK_MAX) && !same_pdir) {
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| 		return(EMLINK);
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| 	}
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|   } else {
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| 	if (old_ip == new_ip) /* old=new */
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| 		return(OK); /* do NOT update directory times in this case */
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| 
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| 	/* dir ? */
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| 	ndir = ((new_ip->pn_va.va_mode & I_TYPE) == I_DIRECTORY);
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| 	if (odir == TRUE && ndir == FALSE) return(ENOTDIR);
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| 	if (odir == FALSE && ndir == TRUE) return(EISDIR);
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|   }
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| 
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|   /* If a process has another root directory than the system root, we might
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|    * "accidently" be moving it's working directory to a place where it's
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|    * root directory isn't a super directory of it anymore. This can make
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|    * the function chroot useless. If chroot will be used often we should
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|    * probably check for it here. */
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| 
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|   /* The rename will probably work. Only two things can go wrong now:
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|    * 1. being unable to remove the new file. (when new file already exists)
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|    * 2. being unable to make the new directory entry. (new file doesn't exists)
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|    *     [directory has to grow by one block and cannot because the disk
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|    *      is completely full].
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|    * 3. Something (doubtfully) else depending on the FS.
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|    */
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| 
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|   if (buildpath) {
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| 	pcn_src.pcn_po_full = old_ip->pn_po;
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| 
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| 	if (puffs_path_pcnbuild(global_pu, &pcn_targ, new_dirp) != 0)
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| 		return(EINVAL);
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|   }
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| 
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|   r = global_pu->pu_ops.puffs_node_rename(global_pu, old_dirp, old_ip, &pcn_src,
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| 						new_dirp, new_ip, &pcn_targ);
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|   if (r > 0) r = -r;
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| 
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|   if (buildpath) {
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| 	if (r) {
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| 		global_pu->pu_pathfree(global_pu, &pcn_targ.pcn_po_full);
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| 	} else {
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| 		struct puffs_pathinfo pi;
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| 		struct puffs_pathobj po_old;
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| 
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| 		/* handle this node */
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| 		po_old = old_ip->pn_po;
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| 		old_ip->pn_po = pcn_targ.pcn_po_full;
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| 
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| 		if (old_ip->pn_va.va_type != VDIR) {
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| 			global_pu->pu_pathfree(global_pu, &po_old);
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| 			return(OK);
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| 		}
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| 
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| 		/* handle all child nodes for DIRs */
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| 		pi.pi_old = &pcn_src.pcn_po_full;
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| 		pi.pi_new = &pcn_targ.pcn_po_full;
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| 
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| 		PU_LOCK();
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| 		if (puffs_pn_nodewalk(global_pu, puffs_path_prefixadj, &pi)
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| 				!= NULL) {
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| 			/* Actually nomem */
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| 			return(EINVAL);
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| 		}
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| 		PU_UNLOCK();
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| 		global_pu->pu_pathfree(global_pu, &po_old);
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| 	}
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|   }
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| 
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|   (void)clock_time(&cur_time);
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|   update_timens(old_dirp, MTIME | CTIME, &cur_time);
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|   update_timens(new_dirp, MTIME | CTIME, &cur_time);
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| 
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|   /* XXX see release_node comment in fs_unlink */
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|   if (new_ip && new_ip->pn_count == 0) {
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| 	release_node(global_pu, new_ip);
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|   }
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| 
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|   return(r);
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| }
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| 
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| static int remove_dir(struct puffs_node *pn_dir, struct puffs_node *pn,
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| 	struct puffs_cn *pcn);
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| static int unlink_file(struct puffs_node *dirp, struct puffs_node *pn,
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| 	struct puffs_cn *pcn);
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| 
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| /*===========================================================================*
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|  *				fs_unlink				     *
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|  *===========================================================================*/
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| int fs_unlink(ino_t dir_nr, char *name, int call)
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| {
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| /* Perform the unlink(name) or rmdir(name) system call. The code for these two
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|  * is almost the same.  They differ only in some condition testing.
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|  */
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|   int r;
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|   struct puffs_node *pn, *pn_dir;
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|   struct timespec cur_time;
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|   struct puffs_kcn pkcnp;
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|   struct puffs_cn pcn = {&pkcnp, 0, {0,0,0}};
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|   PUFFS_KCREDTOCRED(pcn.pcn_cred, &global_kcred);
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| 
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|   /* Copy the last component */
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|   pcn.pcn_namelen = strlen(name);
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|   assert(pcn.pcn_namelen <= NAME_MAX);
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|   strcpy(pcn.pcn_name, name);
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| 
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|   if ((pn_dir = puffs_pn_nodewalk(global_pu, 0, &dir_nr)) == NULL)
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| 	return(EINVAL);
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| 
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|   /* The last directory exists. Does the file also exist? */
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|   pn = advance(pn_dir, pcn.pcn_name);
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|   r = err_code;
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| 
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|   /* If error, return pnode. */
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|   if (r != OK)
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|         return(r);
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|   if (pn->pn_mountpoint)
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| 	return EBUSY;
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| 
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|   /* Now test if the call is allowed, separately for unlink() and rmdir(). */
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|   if (call == FSC_UNLINK) {
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| 	r = unlink_file(pn_dir, pn, &pcn);
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|   } else {
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| 	r = remove_dir(pn_dir, pn, &pcn); /* call is RMDIR */
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|   }
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| 
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|   if (pn->pn_va.va_nlink != 0) {
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| 	(void)clock_time(&cur_time);
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| 	update_timens(pn, CTIME, &cur_time);
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| 	update_timens(pn_dir, MTIME | CTIME, &cur_time);
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|   }
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| 
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|   /* XXX Ideally, we should check pn->pn_flags & PUFFS_NODE_REMOVED, but
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|    * librefuse doesn't set it (neither manually or via puffs_pn_remove() ).
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|    * Thus we just check that "pn_count == 0". Otherwise release_node()
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|    * will be called in fs_put().
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|    */
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|   if (pn->pn_count == 0)
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| 	release_node(global_pu, pn);
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| 
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|   return(r);
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| }
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| 
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| 
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| /*===========================================================================*
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|  *				remove_dir				     *
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|  *===========================================================================*/
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| static int remove_dir(
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| 	struct puffs_node *pn_dir,	/* parent directory */
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| 	struct puffs_node *pn,    	/* directory to be removed */
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| 	struct puffs_cn *pcn      	/* Name, creads of directory */
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| )
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| {
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|   /* A directory file has to be removed. Five conditions have to met:
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|    * 	- The file must be a directory
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|    *	- The directory must be empty (except for . and ..)
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|    *	- The final component of the path must not be . or ..
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|    *	- The directory must not be the root of a mounted file system (VFS)
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|    *	- The directory must not be anybody's root/working directory (VFS)
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|    */
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| 
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|   /* "." and ".." dentries can be stored in 28 bytes */
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|   #define EMPTY_DIR_DENTRIES_SIZE	28
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|   int r;
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|   char remove_dir_buf[EMPTY_DIR_DENTRIES_SIZE];
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|   struct dirent *dent = (struct dirent*) remove_dir_buf;
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|   int buf_left = EMPTY_DIR_DENTRIES_SIZE;
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|   off_t pos = 0;
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|   int eofflag = 0;
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| 
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|   if (global_pu->pu_ops.puffs_node_rmdir == NULL)
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| 	return(EINVAL);
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| 
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|   if (!S_ISDIR(pn->pn_va.va_mode))
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| 	return(ENOTDIR);
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| 
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|   /* Check if directory is empty */
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|   r = global_pu->pu_ops.puffs_node_readdir(global_pu, pn, dent, &pos,
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| 			(size_t *)&buf_left, pcn->pcn_cred, &eofflag, 0, 0);
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|   if (r) return(EINVAL);
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|   if (!eofflag) return(ENOTEMPTY);
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| 
 | |
|   if (pn->pn_va.va_fileid == global_pu->pu_pn_root->pn_va.va_fileid)
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| 	return(EBUSY); /* can't remove 'root' */
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|   
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|   if (buildpath) {
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| 	r = puffs_path_pcnbuild(global_pu, pcn, pn_dir);
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| 	if (r) return(EINVAL);
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|   }
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| 
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|   r = global_pu->pu_ops.puffs_node_rmdir(global_pu, pn_dir, pn, pcn);
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| 
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|   global_pu->pu_pathfree(global_pu, &pcn->pcn_po_full);
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| 
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|   if (r) return(EINVAL);
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| 
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|   return(OK);
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| }
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| 
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| 
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| /*===========================================================================*
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|  *				unlink_file				     *
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|  *===========================================================================*/
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| static int unlink_file(
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| 	struct puffs_node *dirp,	/* parent directory of file */
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| 	struct puffs_node *pn,  	/* pnode of file, may be NULL too. */
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| 	struct puffs_cn *pcn    	/* Name, creads of file */
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| )
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| {
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| /* Unlink 'file_name'; pn must be the pnode of 'file_name' */
 | |
|   int	r;
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| 
 | |
|   assert(pn != NULL);
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| 
 | |
|   if (global_pu->pu_ops.puffs_node_remove == NULL)
 | |
|   	return(EINVAL);
 | |
| 
 | |
|   if (S_ISDIR(pn->pn_va.va_mode))
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| 	return(EPERM);
 | |
| 
 | |
|   if (buildpath) {
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| 	r = puffs_path_pcnbuild(global_pu, pcn, dirp);
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| 	if (r)
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| 		return(EINVAL);
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|   }
 | |
| 
 | |
|   r = global_pu->pu_ops.puffs_node_remove(global_pu, dirp, pn, pcn);
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| 
 | |
|   global_pu->pu_pathfree(global_pu, &pcn->pcn_po_full);
 | |
| 
 | |
|   if (r) return(EINVAL);
 | |
| 
 | |
|   return(OK);
 | |
| }
 | 
