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linux/fs/udf/namei.c
NeilBrown 88d5baf690
Change inode_operations.mkdir to return struct dentry * 
Some filesystems, such as NFS, cifs, ceph, and fuse, do not have
complete control of sequencing on the actual filesystem (e.g.  on a
different server) and may find that the inode created for a mkdir
request already exists in the icache and dcache by the time the mkdir
request returns.  For example, if the filesystem is mounted twice the
directory could be visible on the other mount before it is on the
original mount, and a pair of name_to_handle_at(), open_by_handle_at()
calls could instantiate the directory inode with an IS_ROOT() dentry
before the first mkdir returns.

This means that the dentry passed to ->mkdir() may not be the one that
is associated with the inode after the ->mkdir() completes.  Some
callers need to interact with the inode after the ->mkdir completes and
they currently need to perform a lookup in the (rare) case that the
dentry is no longer hashed.

This lookup-after-mkdir requires that the directory remains locked to
avoid races.  Planned future patches to lock the dentry rather than the
directory will mean that this lookup cannot be performed atomically with
the mkdir.

To remove this barrier, this patch changes ->mkdir to return the
resulting dentry if it is different from the one passed in.
Possible returns are:
  NULL - the directory was created and no other dentry was used
  ERR_PTR() - an error occurred
  non-NULL - this other dentry was spliced in

This patch only changes file-systems to return "ERR_PTR(err)" instead of
"err" or equivalent transformations.  Subsequent patches will make
further changes to some file-systems to return a correct dentry.

Not all filesystems reliably result in a positive hashed dentry:

- NFS, cifs, hostfs will sometimes need to perform a lookup of
  the name to get inode information.  Races could result in this
  returning something different. Note that this lookup is
  non-atomic which is what we are trying to avoid.  Placing the
  lookup in filesystem code means it only happens when the filesystem
  has no other option.
- kernfs and tracefs leave the dentry negative and the ->revalidate
  operation ensures that lookup will be called to correctly populate
  the dentry.  This could be fixed but I don't think it is important
  to any of the users of vfs_mkdir() which look at the dentry.

The recommendation to use
    d_drop();d_splice_alias()
is ugly but fits with current practice.  A planned future patch will
change this.

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: NeilBrown <neilb@suse.de>
Link: https://lore.kernel.org/r/20250227013949.536172-2-neilb@suse.de
Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-02-27 20:00:17 +01:00

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// SPDX-License-Identifier: GPL-2.0-only
/*
* namei.c
*
* PURPOSE
* Inode name handling routines for the OSTA-UDF(tm) filesystem.
*
* COPYRIGHT
* (C) 1998-2004 Ben Fennema
* (C) 1999-2000 Stelias Computing Inc
*
* HISTORY
*
* 12/12/98 blf Created. Split out the lookup code from dir.c
* 04/19/99 blf link, mknod, symlink support
*/
#include "udfdecl.h"
#include "udf_i.h"
#include "udf_sb.h"
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/sched.h>
#include <linux/crc-itu-t.h>
#include <linux/exportfs.h>
#include <linux/iversion.h>
static inline int udf_match(int len1, const unsigned char *name1, int len2,
const unsigned char *name2)
{
if (len1 != len2)
return 0;
return !memcmp(name1, name2, len1);
}
/**
* udf_fiiter_find_entry - find entry in given directory.
*
* @dir: directory inode to search in
* @child: qstr of the name
* @iter: iter to use for searching
*
* This function searches in the directory @dir for a file name @child. When
* found, @iter points to the position in the directory with given entry.
*
* Returns 0 on success, < 0 on error (including -ENOENT).
*/
static int udf_fiiter_find_entry(struct inode *dir, const struct qstr *child,
struct udf_fileident_iter *iter)
{
int flen;
unsigned char *fname = NULL;
struct super_block *sb = dir->i_sb;
int isdotdot = child->len == 2 &&
child->name[0] == '.' && child->name[1] == '.';
int ret;
fname = kmalloc(UDF_NAME_LEN, GFP_KERNEL);
if (!fname)
return -ENOMEM;
for (ret = udf_fiiter_init(iter, dir, 0);
!ret && iter->pos < dir->i_size;
ret = udf_fiiter_advance(iter)) {
if (iter->fi.fileCharacteristics & FID_FILE_CHAR_DELETED) {
if (!UDF_QUERY_FLAG(sb, UDF_FLAG_UNDELETE))
continue;
}
if (iter->fi.fileCharacteristics & FID_FILE_CHAR_HIDDEN) {
if (!UDF_QUERY_FLAG(sb, UDF_FLAG_UNHIDE))
continue;
}
if ((iter->fi.fileCharacteristics & FID_FILE_CHAR_PARENT) &&
isdotdot)
goto out_ok;
if (!iter->fi.lengthFileIdent)
continue;
flen = udf_get_filename(sb, iter->name,
iter->fi.lengthFileIdent, fname, UDF_NAME_LEN);
if (flen < 0) {
ret = flen;
goto out_err;
}
if (udf_match(flen, fname, child->len, child->name))
goto out_ok;
}
if (!ret)
ret = -ENOENT;
out_err:
udf_fiiter_release(iter);
out_ok:
kfree(fname);
return ret;
}
static struct dentry *udf_lookup(struct inode *dir, struct dentry *dentry,
unsigned int flags)
{
struct inode *inode = NULL;
struct udf_fileident_iter iter;
int err;
if (dentry->d_name.len > UDF_NAME_LEN)
return ERR_PTR(-ENAMETOOLONG);
err = udf_fiiter_find_entry(dir, &dentry->d_name, &iter);
if (err < 0 && err != -ENOENT)
return ERR_PTR(err);
if (err == 0) {
struct kernel_lb_addr loc;
loc = lelb_to_cpu(iter.fi.icb.extLocation);
udf_fiiter_release(&iter);
inode = udf_iget(dir->i_sb, &loc);
}
return d_splice_alias(inode, dentry);
}
static int udf_expand_dir_adinicb(struct inode *inode, udf_pblk_t *block)
{
udf_pblk_t newblock;
struct buffer_head *dbh = NULL;
struct kernel_lb_addr eloc;
struct extent_position epos;
uint8_t alloctype;
struct udf_inode_info *iinfo = UDF_I(inode);
struct udf_fileident_iter iter;
uint8_t *impuse;
int ret;
if (UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_USE_SHORT_AD))
alloctype = ICBTAG_FLAG_AD_SHORT;
else
alloctype = ICBTAG_FLAG_AD_LONG;
if (!inode->i_size) {
iinfo->i_alloc_type = alloctype;
mark_inode_dirty(inode);
return 0;
}
/* alloc block, and copy data to it */
*block = udf_new_block(inode->i_sb, inode,
iinfo->i_location.partitionReferenceNum,
iinfo->i_location.logicalBlockNum, &ret);
if (!(*block))
return ret;
newblock = udf_get_pblock(inode->i_sb, *block,
iinfo->i_location.partitionReferenceNum,
0);
if (newblock == 0xffffffff)
return -EFSCORRUPTED;
dbh = sb_getblk(inode->i_sb, newblock);
if (!dbh)
return -ENOMEM;
lock_buffer(dbh);
memcpy(dbh->b_data, iinfo->i_data, inode->i_size);
memset(dbh->b_data + inode->i_size, 0,
inode->i_sb->s_blocksize - inode->i_size);
set_buffer_uptodate(dbh);
unlock_buffer(dbh);
/* Drop inline data, add block instead */
iinfo->i_alloc_type = alloctype;
memset(iinfo->i_data + iinfo->i_lenEAttr, 0, iinfo->i_lenAlloc);
iinfo->i_lenAlloc = 0;
eloc.logicalBlockNum = *block;
eloc.partitionReferenceNum =
iinfo->i_location.partitionReferenceNum;
iinfo->i_lenExtents = inode->i_size;
epos.bh = NULL;
epos.block = iinfo->i_location;
epos.offset = udf_file_entry_alloc_offset(inode);
ret = udf_add_aext(inode, &epos, &eloc, inode->i_size, 0);
brelse(epos.bh);
if (ret < 0) {
brelse(dbh);
udf_free_blocks(inode->i_sb, inode, &eloc, 0, 1);
return ret;
}
mark_inode_dirty(inode);
/* Now fixup tags in moved directory entries */
for (ret = udf_fiiter_init(&iter, inode, 0);
!ret && iter.pos < inode->i_size;
ret = udf_fiiter_advance(&iter)) {
iter.fi.descTag.tagLocation = cpu_to_le32(*block);
if (iter.fi.lengthOfImpUse != cpu_to_le16(0))
impuse = dbh->b_data + iter.pos +
sizeof(struct fileIdentDesc);
else
impuse = NULL;
udf_fiiter_write_fi(&iter, impuse);
}
brelse(dbh);
/*
* We don't expect the iteration to fail as the directory has been
* already verified to be correct
*/
WARN_ON_ONCE(ret);
udf_fiiter_release(&iter);
return 0;
}
static int udf_fiiter_add_entry(struct inode *dir, struct dentry *dentry,
struct udf_fileident_iter *iter)
{
struct udf_inode_info *dinfo = UDF_I(dir);
int nfidlen, namelen = 0;
int ret;
int off, blksize = 1 << dir->i_blkbits;
udf_pblk_t block;
char name[UDF_NAME_LEN_CS0];
if (dentry) {
namelen = udf_put_filename(dir->i_sb, dentry->d_name.name,
dentry->d_name.len,
name, UDF_NAME_LEN_CS0);
if (!namelen)
return -ENAMETOOLONG;
}
nfidlen = ALIGN(sizeof(struct fileIdentDesc) + namelen, UDF_NAME_PAD);
for (ret = udf_fiiter_init(iter, dir, 0);
!ret && iter->pos < dir->i_size;
ret = udf_fiiter_advance(iter)) {
if (iter->fi.fileCharacteristics & FID_FILE_CHAR_DELETED) {
if (udf_dir_entry_len(&iter->fi) == nfidlen) {
iter->fi.descTag.tagSerialNum = cpu_to_le16(1);
iter->fi.fileVersionNum = cpu_to_le16(1);
iter->fi.fileCharacteristics = 0;
iter->fi.lengthFileIdent = namelen;
iter->fi.lengthOfImpUse = cpu_to_le16(0);
memcpy(iter->namebuf, name, namelen);
iter->name = iter->namebuf;
return 0;
}
}
}
if (ret) {
udf_fiiter_release(iter);
return ret;
}
if (dinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB &&
blksize - udf_ext0_offset(dir) - iter->pos < nfidlen) {
udf_fiiter_release(iter);
ret = udf_expand_dir_adinicb(dir, &block);
if (ret)
return ret;
ret = udf_fiiter_init(iter, dir, dir->i_size);
if (ret < 0)
return ret;
}
/* Get blocknumber to use for entry tag */
if (dinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
block = dinfo->i_location.logicalBlockNum;
} else {
block = iter->eloc.logicalBlockNum +
((iter->elen - 1) >> dir->i_blkbits);
}
off = iter->pos & (blksize - 1);
if (!off)
off = blksize;
/* Entry fits into current block? */
if (blksize - udf_ext0_offset(dir) - off >= nfidlen)
goto store_fi;
ret = udf_fiiter_append_blk(iter);
if (ret) {
udf_fiiter_release(iter);
return ret;
}
/* Entry will be completely in the new block? Update tag location... */
if (!(iter->pos & (blksize - 1)))
block = iter->eloc.logicalBlockNum +
((iter->elen - 1) >> dir->i_blkbits);
store_fi:
memset(&iter->fi, 0, sizeof(struct fileIdentDesc));
if (UDF_SB(dir->i_sb)->s_udfrev >= 0x0200)
udf_new_tag((char *)(&iter->fi), TAG_IDENT_FID, 3, 1, block,
sizeof(struct tag));
else
udf_new_tag((char *)(&iter->fi), TAG_IDENT_FID, 2, 1, block,
sizeof(struct tag));
iter->fi.fileVersionNum = cpu_to_le16(1);
iter->fi.lengthFileIdent = namelen;
iter->fi.lengthOfImpUse = cpu_to_le16(0);
memcpy(iter->namebuf, name, namelen);
iter->name = iter->namebuf;
dir->i_size += nfidlen;
if (dinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
dinfo->i_lenAlloc += nfidlen;
} else {
/* Truncate last extent to proper size */
udf_fiiter_update_elen(iter, iter->elen -
(dinfo->i_lenExtents - dir->i_size));
}
mark_inode_dirty(dir);
return 0;
}
static void udf_fiiter_delete_entry(struct udf_fileident_iter *iter)
{
iter->fi.fileCharacteristics |= FID_FILE_CHAR_DELETED;
if (UDF_QUERY_FLAG(iter->dir->i_sb, UDF_FLAG_STRICT))
memset(&iter->fi.icb, 0x00, sizeof(struct long_ad));
udf_fiiter_write_fi(iter, NULL);
}
static void udf_add_fid_counter(struct super_block *sb, bool dir, int val)
{
struct logicalVolIntegrityDescImpUse *lvidiu = udf_sb_lvidiu(sb);
if (!lvidiu)
return;
mutex_lock(&UDF_SB(sb)->s_alloc_mutex);
if (dir)
le32_add_cpu(&lvidiu->numDirs, val);
else
le32_add_cpu(&lvidiu->numFiles, val);
udf_updated_lvid(sb);
mutex_unlock(&UDF_SB(sb)->s_alloc_mutex);
}
static int udf_add_nondir(struct dentry *dentry, struct inode *inode)
{
struct udf_inode_info *iinfo = UDF_I(inode);
struct inode *dir = d_inode(dentry->d_parent);
struct udf_fileident_iter iter;
int err;
err = udf_fiiter_add_entry(dir, dentry, &iter);
if (err) {
inode_dec_link_count(inode);
discard_new_inode(inode);
return err;
}
iter.fi.icb.extLength = cpu_to_le32(inode->i_sb->s_blocksize);
iter.fi.icb.extLocation = cpu_to_lelb(iinfo->i_location);
*(__le32 *)((struct allocDescImpUse *)iter.fi.icb.impUse)->impUse =
cpu_to_le32(iinfo->i_unique & 0x00000000FFFFFFFFUL);
udf_fiiter_write_fi(&iter, NULL);
inode_set_mtime_to_ts(dir, inode_set_ctime_current(dir));
mark_inode_dirty(dir);
udf_fiiter_release(&iter);
udf_add_fid_counter(dir->i_sb, false, 1);
d_instantiate_new(dentry, inode);
return 0;
}
static int udf_create(struct mnt_idmap *idmap, struct inode *dir,
struct dentry *dentry, umode_t mode, bool excl)
{
struct inode *inode = udf_new_inode(dir, mode);
if (IS_ERR(inode))
return PTR_ERR(inode);
inode->i_data.a_ops = &udf_aops;
inode->i_op = &udf_file_inode_operations;
inode->i_fop = &udf_file_operations;
mark_inode_dirty(inode);
return udf_add_nondir(dentry, inode);
}
static int udf_tmpfile(struct mnt_idmap *idmap, struct inode *dir,
struct file *file, umode_t mode)
{
struct inode *inode = udf_new_inode(dir, mode);
if (IS_ERR(inode))
return PTR_ERR(inode);
inode->i_data.a_ops = &udf_aops;
inode->i_op = &udf_file_inode_operations;
inode->i_fop = &udf_file_operations;
mark_inode_dirty(inode);
d_tmpfile(file, inode);
unlock_new_inode(inode);
return finish_open_simple(file, 0);
}
static int udf_mknod(struct mnt_idmap *idmap, struct inode *dir,
struct dentry *dentry, umode_t mode, dev_t rdev)
{
struct inode *inode;
if (!old_valid_dev(rdev))
return -EINVAL;
inode = udf_new_inode(dir, mode);
if (IS_ERR(inode))
return PTR_ERR(inode);
init_special_inode(inode, mode, rdev);
return udf_add_nondir(dentry, inode);
}
static struct dentry *udf_mkdir(struct mnt_idmap *idmap, struct inode *dir,
struct dentry *dentry, umode_t mode)
{
struct inode *inode;
struct udf_fileident_iter iter;
int err;
struct udf_inode_info *dinfo = UDF_I(dir);
struct udf_inode_info *iinfo;
inode = udf_new_inode(dir, S_IFDIR | mode);
if (IS_ERR(inode))
return ERR_CAST(inode);
iinfo = UDF_I(inode);
inode->i_op = &udf_dir_inode_operations;
inode->i_fop = &udf_dir_operations;
err = udf_fiiter_add_entry(inode, NULL, &iter);
if (err) {
clear_nlink(inode);
discard_new_inode(inode);
return ERR_PTR(err);
}
set_nlink(inode, 2);
iter.fi.icb.extLength = cpu_to_le32(inode->i_sb->s_blocksize);
iter.fi.icb.extLocation = cpu_to_lelb(dinfo->i_location);
*(__le32 *)((struct allocDescImpUse *)iter.fi.icb.impUse)->impUse =
cpu_to_le32(dinfo->i_unique & 0x00000000FFFFFFFFUL);
iter.fi.fileCharacteristics =
FID_FILE_CHAR_DIRECTORY | FID_FILE_CHAR_PARENT;
udf_fiiter_write_fi(&iter, NULL);
udf_fiiter_release(&iter);
mark_inode_dirty(inode);
err = udf_fiiter_add_entry(dir, dentry, &iter);
if (err) {
clear_nlink(inode);
discard_new_inode(inode);
return ERR_PTR(err);
}
iter.fi.icb.extLength = cpu_to_le32(inode->i_sb->s_blocksize);
iter.fi.icb.extLocation = cpu_to_lelb(iinfo->i_location);
*(__le32 *)((struct allocDescImpUse *)iter.fi.icb.impUse)->impUse =
cpu_to_le32(iinfo->i_unique & 0x00000000FFFFFFFFUL);
iter.fi.fileCharacteristics |= FID_FILE_CHAR_DIRECTORY;
udf_fiiter_write_fi(&iter, NULL);
udf_fiiter_release(&iter);
udf_add_fid_counter(dir->i_sb, true, 1);
inc_nlink(dir);
inode_set_mtime_to_ts(dir, inode_set_ctime_current(dir));
mark_inode_dirty(dir);
d_instantiate_new(dentry, inode);
return NULL;
}
static int empty_dir(struct inode *dir)
{
struct udf_fileident_iter iter;
int ret;
for (ret = udf_fiiter_init(&iter, dir, 0);
!ret && iter.pos < dir->i_size;
ret = udf_fiiter_advance(&iter)) {
if (iter.fi.lengthFileIdent &&
!(iter.fi.fileCharacteristics & FID_FILE_CHAR_DELETED)) {
udf_fiiter_release(&iter);
return 0;
}
}
udf_fiiter_release(&iter);
return 1;
}
static int udf_rmdir(struct inode *dir, struct dentry *dentry)
{
int ret;
struct inode *inode = d_inode(dentry);
struct udf_fileident_iter iter;
struct kernel_lb_addr tloc;
ret = udf_fiiter_find_entry(dir, &dentry->d_name, &iter);
if (ret)
goto out;
ret = -EFSCORRUPTED;
tloc = lelb_to_cpu(iter.fi.icb.extLocation);
if (udf_get_lb_pblock(dir->i_sb, &tloc, 0) != inode->i_ino)
goto end_rmdir;
ret = -ENOTEMPTY;
if (!empty_dir(inode))
goto end_rmdir;
udf_fiiter_delete_entry(&iter);
if (inode->i_nlink != 2)
udf_warn(inode->i_sb, "empty directory has nlink != 2 (%u)\n",
inode->i_nlink);
clear_nlink(inode);
inode->i_size = 0;
if (dir->i_nlink >= 3)
inode_dec_link_count(dir);
else
udf_warn(inode->i_sb, "parent dir link count too low (%u)\n",
dir->i_nlink);
udf_add_fid_counter(dir->i_sb, true, -1);
inode_set_mtime_to_ts(dir,
inode_set_ctime_to_ts(dir, inode_set_ctime_current(inode)));
mark_inode_dirty(dir);
ret = 0;
end_rmdir:
udf_fiiter_release(&iter);
out:
return ret;
}
static int udf_unlink(struct inode *dir, struct dentry *dentry)
{
int ret;
struct inode *inode = d_inode(dentry);
struct udf_fileident_iter iter;
struct kernel_lb_addr tloc;
ret = udf_fiiter_find_entry(dir, &dentry->d_name, &iter);
if (ret)
goto out;
ret = -EFSCORRUPTED;
tloc = lelb_to_cpu(iter.fi.icb.extLocation);
if (udf_get_lb_pblock(dir->i_sb, &tloc, 0) != inode->i_ino)
goto end_unlink;
if (!inode->i_nlink) {
udf_debug("Deleting nonexistent file (%lu), %u\n",
inode->i_ino, inode->i_nlink);
set_nlink(inode, 1);
}
udf_fiiter_delete_entry(&iter);
inode_set_mtime_to_ts(dir, inode_set_ctime_current(dir));
mark_inode_dirty(dir);
inode_dec_link_count(inode);
udf_add_fid_counter(dir->i_sb, false, -1);
inode_set_ctime_to_ts(inode, inode_get_ctime(dir));
ret = 0;
end_unlink:
udf_fiiter_release(&iter);
out:
return ret;
}
static int udf_symlink(struct mnt_idmap *idmap, struct inode *dir,
struct dentry *dentry, const char *symname)
{
struct inode *inode;
struct pathComponent *pc;
const char *compstart;
struct extent_position epos = {};
int eoffset, elen = 0;
uint8_t *ea;
int err;
udf_pblk_t block;
unsigned char *name = NULL;
int namelen;
struct udf_inode_info *iinfo;
struct super_block *sb = dir->i_sb;
name = kmalloc(UDF_NAME_LEN_CS0, GFP_KERNEL);
if (!name) {
err = -ENOMEM;
goto out;
}
inode = udf_new_inode(dir, S_IFLNK | 0777);
if (IS_ERR(inode)) {
err = PTR_ERR(inode);
goto out;
}
iinfo = UDF_I(inode);
down_write(&iinfo->i_data_sem);
inode->i_data.a_ops = &udf_symlink_aops;
inode->i_op = &udf_symlink_inode_operations;
inode_nohighmem(inode);
if (iinfo->i_alloc_type != ICBTAG_FLAG_AD_IN_ICB) {
struct kernel_lb_addr eloc;
uint32_t bsize;
block = udf_new_block(sb, inode,
iinfo->i_location.partitionReferenceNum,
iinfo->i_location.logicalBlockNum, &err);
if (!block)
goto out_no_entry;
epos.block = iinfo->i_location;
epos.offset = udf_file_entry_alloc_offset(inode);
epos.bh = NULL;
eloc.logicalBlockNum = block;
eloc.partitionReferenceNum =
iinfo->i_location.partitionReferenceNum;
bsize = sb->s_blocksize;
iinfo->i_lenExtents = bsize;
err = udf_add_aext(inode, &epos, &eloc, bsize, 0);
brelse(epos.bh);
if (err < 0) {
udf_free_blocks(sb, inode, &eloc, 0, 1);
goto out_no_entry;
}
block = udf_get_pblock(sb, block,
iinfo->i_location.partitionReferenceNum,
0);
epos.bh = sb_getblk(sb, block);
if (unlikely(!epos.bh)) {
err = -ENOMEM;
udf_free_blocks(sb, inode, &eloc, 0, 1);
goto out_no_entry;
}
lock_buffer(epos.bh);
memset(epos.bh->b_data, 0x00, bsize);
set_buffer_uptodate(epos.bh);
unlock_buffer(epos.bh);
mark_buffer_dirty_inode(epos.bh, inode);
ea = epos.bh->b_data + udf_ext0_offset(inode);
} else
ea = iinfo->i_data + iinfo->i_lenEAttr;
eoffset = sb->s_blocksize - udf_ext0_offset(inode);
pc = (struct pathComponent *)ea;
if (*symname == '/') {
do {
symname++;
} while (*symname == '/');
pc->componentType = 1;
pc->lengthComponentIdent = 0;
pc->componentFileVersionNum = 0;
elen += sizeof(struct pathComponent);
}
err = -ENAMETOOLONG;
while (*symname) {
if (elen + sizeof(struct pathComponent) > eoffset)
goto out_no_entry;
pc = (struct pathComponent *)(ea + elen);
compstart = symname;
do {
symname++;
} while (*symname && *symname != '/');
pc->componentType = 5;
pc->lengthComponentIdent = 0;
pc->componentFileVersionNum = 0;
if (compstart[0] == '.') {
if ((symname - compstart) == 1)
pc->componentType = 4;
else if ((symname - compstart) == 2 &&
compstart[1] == '.')
pc->componentType = 3;
}
if (pc->componentType == 5) {
namelen = udf_put_filename(sb, compstart,
symname - compstart,
name, UDF_NAME_LEN_CS0);
if (!namelen)
goto out_no_entry;
if (elen + sizeof(struct pathComponent) + namelen >
eoffset)
goto out_no_entry;
else
pc->lengthComponentIdent = namelen;
memcpy(pc->componentIdent, name, namelen);
}
elen += sizeof(struct pathComponent) + pc->lengthComponentIdent;
if (*symname) {
do {
symname++;
} while (*symname == '/');
}
}
brelse(epos.bh);
inode->i_size = elen;
if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB)
iinfo->i_lenAlloc = inode->i_size;
else
udf_truncate_tail_extent(inode);
mark_inode_dirty(inode);
up_write(&iinfo->i_data_sem);
err = udf_add_nondir(dentry, inode);
out:
kfree(name);
return err;
out_no_entry:
up_write(&iinfo->i_data_sem);
inode_dec_link_count(inode);
discard_new_inode(inode);
goto out;
}
static int udf_link(struct dentry *old_dentry, struct inode *dir,
struct dentry *dentry)
{
struct inode *inode = d_inode(old_dentry);
struct udf_fileident_iter iter;
int err;
err = udf_fiiter_add_entry(dir, dentry, &iter);
if (err)
return err;
iter.fi.icb.extLength = cpu_to_le32(inode->i_sb->s_blocksize);
iter.fi.icb.extLocation = cpu_to_lelb(UDF_I(inode)->i_location);
if (UDF_SB(inode->i_sb)->s_lvid_bh) {
*(__le32 *)((struct allocDescImpUse *)iter.fi.icb.impUse)->impUse =
cpu_to_le32(lvid_get_unique_id(inode->i_sb));
}
udf_fiiter_write_fi(&iter, NULL);
udf_fiiter_release(&iter);
inc_nlink(inode);
udf_add_fid_counter(dir->i_sb, false, 1);
inode_set_ctime_current(inode);
mark_inode_dirty(inode);
inode_set_mtime_to_ts(dir, inode_set_ctime_current(dir));
mark_inode_dirty(dir);
ihold(inode);
d_instantiate(dentry, inode);
return 0;
}
/* Anybody can rename anything with this: the permission checks are left to the
* higher-level routines.
*/
static int udf_rename(struct mnt_idmap *idmap, struct inode *old_dir,
struct dentry *old_dentry, struct inode *new_dir,
struct dentry *new_dentry, unsigned int flags)
{
struct inode *old_inode = d_inode(old_dentry);
struct inode *new_inode = d_inode(new_dentry);
struct udf_fileident_iter oiter, niter, diriter;
bool has_diriter = false, is_dir = false;
int retval;
struct kernel_lb_addr tloc;
if (flags & ~RENAME_NOREPLACE)
return -EINVAL;
retval = udf_fiiter_find_entry(old_dir, &old_dentry->d_name, &oiter);
if (retval)
return retval;
tloc = lelb_to_cpu(oiter.fi.icb.extLocation);
if (udf_get_lb_pblock(old_dir->i_sb, &tloc, 0) != old_inode->i_ino) {
retval = -ENOENT;
goto out_oiter;
}
if (S_ISDIR(old_inode->i_mode)) {
if (new_inode) {
retval = -ENOTEMPTY;
if (!empty_dir(new_inode))
goto out_oiter;
retval = -EFSCORRUPTED;
if (new_inode->i_nlink != 2)
goto out_oiter;
}
retval = -EFSCORRUPTED;
if (old_dir->i_nlink < 3)
goto out_oiter;
is_dir = true;
} else if (new_inode) {
retval = -EFSCORRUPTED;
if (new_inode->i_nlink < 1)
goto out_oiter;
}
if (is_dir && old_dir != new_dir) {
retval = udf_fiiter_find_entry(old_inode, &dotdot_name,
&diriter);
if (retval == -ENOENT) {
udf_err(old_inode->i_sb,
"directory (ino %lu) has no '..' entry\n",
old_inode->i_ino);
retval = -EFSCORRUPTED;
}
if (retval)
goto out_oiter;
has_diriter = true;
tloc = lelb_to_cpu(diriter.fi.icb.extLocation);
if (udf_get_lb_pblock(old_inode->i_sb, &tloc, 0) !=
old_dir->i_ino) {
retval = -EFSCORRUPTED;
udf_err(old_inode->i_sb,
"directory (ino %lu) has parent entry pointing to another inode (%lu != %u)\n",
old_inode->i_ino, old_dir->i_ino,
udf_get_lb_pblock(old_inode->i_sb, &tloc, 0));
goto out_oiter;
}
}
retval = udf_fiiter_find_entry(new_dir, &new_dentry->d_name, &niter);
if (retval && retval != -ENOENT)
goto out_oiter;
/* Entry found but not passed by VFS? */
if (!retval && !new_inode) {
retval = -EFSCORRUPTED;
udf_fiiter_release(&niter);
goto out_oiter;
}
/* Entry not found? Need to add one... */
if (retval) {
udf_fiiter_release(&niter);
retval = udf_fiiter_add_entry(new_dir, new_dentry, &niter);
if (retval)
goto out_oiter;
}
/*
* Like most other Unix systems, set the ctime for inodes on a
* rename.
*/
inode_set_ctime_current(old_inode);
mark_inode_dirty(old_inode);
/*
* ok, that's it
*/
niter.fi.fileVersionNum = oiter.fi.fileVersionNum;
niter.fi.fileCharacteristics = oiter.fi.fileCharacteristics;
memcpy(&(niter.fi.icb), &(oiter.fi.icb), sizeof(oiter.fi.icb));
udf_fiiter_write_fi(&niter, NULL);
udf_fiiter_release(&niter);
/*
* The old entry may have moved due to new entry allocation. Find it
* again.
*/
udf_fiiter_release(&oiter);
retval = udf_fiiter_find_entry(old_dir, &old_dentry->d_name, &oiter);
if (retval) {
udf_err(old_dir->i_sb,
"failed to find renamed entry again in directory (ino %lu)\n",
old_dir->i_ino);
} else {
udf_fiiter_delete_entry(&oiter);
udf_fiiter_release(&oiter);
}
if (new_inode) {
inode_set_ctime_current(new_inode);
inode_dec_link_count(new_inode);
udf_add_fid_counter(old_dir->i_sb, S_ISDIR(new_inode->i_mode),
-1);
}
inode_set_mtime_to_ts(old_dir, inode_set_ctime_current(old_dir));
inode_set_mtime_to_ts(new_dir, inode_set_ctime_current(new_dir));
mark_inode_dirty(old_dir);
mark_inode_dirty(new_dir);
if (has_diriter) {
diriter.fi.icb.extLocation =
cpu_to_lelb(UDF_I(new_dir)->i_location);
udf_fiiter_write_fi(&diriter, NULL);
udf_fiiter_release(&diriter);
}
if (is_dir) {
inode_dec_link_count(old_dir);
if (new_inode)
inode_dec_link_count(new_inode);
else {
inc_nlink(new_dir);
mark_inode_dirty(new_dir);
}
}
return 0;
out_oiter:
if (has_diriter)
udf_fiiter_release(&diriter);
udf_fiiter_release(&oiter);
return retval;
}
static struct dentry *udf_get_parent(struct dentry *child)
{
struct kernel_lb_addr tloc;
struct udf_fileident_iter iter;
int err;
err = udf_fiiter_find_entry(d_inode(child), &dotdot_name, &iter);
if (err)
return ERR_PTR(err);
tloc = lelb_to_cpu(iter.fi.icb.extLocation);
udf_fiiter_release(&iter);
return d_obtain_alias(udf_iget(child->d_sb, &tloc));
}
static struct dentry *udf_nfs_get_inode(struct super_block *sb, u32 block,
u16 partref, __u32 generation)
{
struct inode *inode;
struct kernel_lb_addr loc;
if (block == 0)
return ERR_PTR(-ESTALE);
loc.logicalBlockNum = block;
loc.partitionReferenceNum = partref;
inode = udf_iget(sb, &loc);
if (IS_ERR(inode))
return ERR_CAST(inode);
if (generation && inode->i_generation != generation) {
iput(inode);
return ERR_PTR(-ESTALE);
}
return d_obtain_alias(inode);
}
static struct dentry *udf_fh_to_dentry(struct super_block *sb,
struct fid *fid, int fh_len, int fh_type)
{
if (fh_len < 3 ||
(fh_type != FILEID_UDF_WITH_PARENT &&
fh_type != FILEID_UDF_WITHOUT_PARENT))
return NULL;
return udf_nfs_get_inode(sb, fid->udf.block, fid->udf.partref,
fid->udf.generation);
}
static struct dentry *udf_fh_to_parent(struct super_block *sb,
struct fid *fid, int fh_len, int fh_type)
{
if (fh_len < 5 || fh_type != FILEID_UDF_WITH_PARENT)
return NULL;
return udf_nfs_get_inode(sb, fid->udf.parent_block,
fid->udf.parent_partref,
fid->udf.parent_generation);
}
static int udf_encode_fh(struct inode *inode, __u32 *fh, int *lenp,
struct inode *parent)
{
int len = *lenp;
struct kernel_lb_addr location = UDF_I(inode)->i_location;
struct fid *fid = (struct fid *)fh;
int type = FILEID_UDF_WITHOUT_PARENT;
if (parent && (len < 5)) {
*lenp = 5;
return FILEID_INVALID;
} else if (len < 3) {
*lenp = 3;
return FILEID_INVALID;
}
*lenp = 3;
fid->udf.block = location.logicalBlockNum;
fid->udf.partref = location.partitionReferenceNum;
fid->udf.parent_partref = 0;
fid->udf.generation = inode->i_generation;
if (parent) {
location = UDF_I(parent)->i_location;
fid->udf.parent_block = location.logicalBlockNum;
fid->udf.parent_partref = location.partitionReferenceNum;
fid->udf.parent_generation = inode->i_generation;
*lenp = 5;
type = FILEID_UDF_WITH_PARENT;
}
return type;
}
const struct export_operations udf_export_ops = {
.encode_fh = udf_encode_fh,
.fh_to_dentry = udf_fh_to_dentry,
.fh_to_parent = udf_fh_to_parent,
.get_parent = udf_get_parent,
};
const struct inode_operations udf_dir_inode_operations = {
.lookup = udf_lookup,
.create = udf_create,
.link = udf_link,
.unlink = udf_unlink,
.symlink = udf_symlink,
.mkdir = udf_mkdir,
.rmdir = udf_rmdir,
.mknod = udf_mknod,
.rename = udf_rename,
.tmpfile = udf_tmpfile,
};
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