linux/fs/udf/ialloc.c
Christian Brauner 21cb47be6f
inode: make init and permission helpers idmapped mount aware
The inode_owner_or_capable() helper determines whether the caller is the
owner of the inode or is capable with respect to that inode. Allow it to
handle idmapped mounts. If the inode is accessed through an idmapped
mount it according to the mount's user namespace. Afterwards the checks
are identical to non-idmapped mounts. If the initial user namespace is
passed nothing changes so non-idmapped mounts will see identical
behavior as before.

Similarly, allow the inode_init_owner() helper to handle idmapped
mounts. It initializes a new inode on idmapped mounts by mapping the
fsuid and fsgid of the caller from the mount's user namespace. If the
initial user namespace is passed nothing changes so non-idmapped mounts
will see identical behavior as before.

Link: https://lore.kernel.org/r/20210121131959.646623-7-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: James Morris <jamorris@linux.microsoft.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2021-01-24 14:27:16 +01:00

141 lines
3.5 KiB
C

/*
* ialloc.c
*
* PURPOSE
* Inode allocation handling routines for the OSTA-UDF(tm) filesystem.
*
* COPYRIGHT
* This file is distributed under the terms of the GNU General Public
* License (GPL). Copies of the GPL can be obtained from:
* ftp://prep.ai.mit.edu/pub/gnu/GPL
* Each contributing author retains all rights to their own work.
*
* (C) 1998-2001 Ben Fennema
*
* HISTORY
*
* 02/24/99 blf Created.
*
*/
#include "udfdecl.h"
#include <linux/fs.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include "udf_i.h"
#include "udf_sb.h"
void udf_free_inode(struct inode *inode)
{
struct super_block *sb = inode->i_sb;
struct udf_sb_info *sbi = UDF_SB(sb);
struct logicalVolIntegrityDescImpUse *lvidiu = udf_sb_lvidiu(sb);
if (lvidiu) {
mutex_lock(&sbi->s_alloc_mutex);
if (S_ISDIR(inode->i_mode))
le32_add_cpu(&lvidiu->numDirs, -1);
else
le32_add_cpu(&lvidiu->numFiles, -1);
udf_updated_lvid(sb);
mutex_unlock(&sbi->s_alloc_mutex);
}
udf_free_blocks(sb, NULL, &UDF_I(inode)->i_location, 0, 1);
}
struct inode *udf_new_inode(struct inode *dir, umode_t mode)
{
struct super_block *sb = dir->i_sb;
struct udf_sb_info *sbi = UDF_SB(sb);
struct inode *inode;
udf_pblk_t block;
uint32_t start = UDF_I(dir)->i_location.logicalBlockNum;
struct udf_inode_info *iinfo;
struct udf_inode_info *dinfo = UDF_I(dir);
struct logicalVolIntegrityDescImpUse *lvidiu;
int err;
inode = new_inode(sb);
if (!inode)
return ERR_PTR(-ENOMEM);
iinfo = UDF_I(inode);
if (UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_USE_EXTENDED_FE)) {
iinfo->i_efe = 1;
if (UDF_VERS_USE_EXTENDED_FE > sbi->s_udfrev)
sbi->s_udfrev = UDF_VERS_USE_EXTENDED_FE;
iinfo->i_data = kzalloc(inode->i_sb->s_blocksize -
sizeof(struct extendedFileEntry),
GFP_KERNEL);
} else {
iinfo->i_efe = 0;
iinfo->i_data = kzalloc(inode->i_sb->s_blocksize -
sizeof(struct fileEntry),
GFP_KERNEL);
}
if (!iinfo->i_data) {
iput(inode);
return ERR_PTR(-ENOMEM);
}
err = -ENOSPC;
block = udf_new_block(dir->i_sb, NULL,
dinfo->i_location.partitionReferenceNum,
start, &err);
if (err) {
iput(inode);
return ERR_PTR(err);
}
lvidiu = udf_sb_lvidiu(sb);
if (lvidiu) {
iinfo->i_unique = lvid_get_unique_id(sb);
inode->i_generation = iinfo->i_unique;
mutex_lock(&sbi->s_alloc_mutex);
if (S_ISDIR(mode))
le32_add_cpu(&lvidiu->numDirs, 1);
else
le32_add_cpu(&lvidiu->numFiles, 1);
udf_updated_lvid(sb);
mutex_unlock(&sbi->s_alloc_mutex);
}
inode_init_owner(&init_user_ns, inode, dir, mode);
if (UDF_QUERY_FLAG(sb, UDF_FLAG_UID_SET))
inode->i_uid = sbi->s_uid;
if (UDF_QUERY_FLAG(sb, UDF_FLAG_GID_SET))
inode->i_gid = sbi->s_gid;
iinfo->i_location.logicalBlockNum = block;
iinfo->i_location.partitionReferenceNum =
dinfo->i_location.partitionReferenceNum;
inode->i_ino = udf_get_lb_pblock(sb, &iinfo->i_location, 0);
inode->i_blocks = 0;
iinfo->i_lenEAttr = 0;
iinfo->i_lenAlloc = 0;
iinfo->i_use = 0;
iinfo->i_checkpoint = 1;
iinfo->i_extraPerms = FE_PERM_U_CHATTR;
udf_update_extra_perms(inode, mode);
if (UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_USE_AD_IN_ICB))
iinfo->i_alloc_type = ICBTAG_FLAG_AD_IN_ICB;
else if (UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_USE_SHORT_AD))
iinfo->i_alloc_type = ICBTAG_FLAG_AD_SHORT;
else
iinfo->i_alloc_type = ICBTAG_FLAG_AD_LONG;
inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode);
iinfo->i_crtime = inode->i_mtime;
if (unlikely(insert_inode_locked(inode) < 0)) {
make_bad_inode(inode);
iput(inode);
return ERR_PTR(-EIO);
}
mark_inode_dirty(inode);
return inode;
}