WSL2-Linux-Kernel/fs/xfs/libxfs/xfs_dir2.c

752 строки
17 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2000-2001,2005 Silicon Graphics, Inc.
* All Rights Reserved.
*/
#include "xfs.h"
#include "xfs_fs.h"
#include "xfs_shared.h"
#include "xfs_format.h"
#include "xfs_log_format.h"
#include "xfs_trans_resv.h"
#include "xfs_mount.h"
#include "xfs_inode.h"
#include "xfs_trans.h"
#include "xfs_bmap.h"
#include "xfs_dir2.h"
#include "xfs_dir2_priv.h"
#include "xfs_errortag.h"
#include "xfs_error.h"
#include "xfs_trace.h"
const struct xfs_name xfs_name_dotdot = {
.name = (const unsigned char *)"..",
.len = 2,
.type = XFS_DIR3_FT_DIR,
};
/*
* Convert inode mode to directory entry filetype
*/
unsigned char
xfs_mode_to_ftype(
int mode)
{
switch (mode & S_IFMT) {
case S_IFREG:
return XFS_DIR3_FT_REG_FILE;
case S_IFDIR:
return XFS_DIR3_FT_DIR;
case S_IFCHR:
return XFS_DIR3_FT_CHRDEV;
case S_IFBLK:
return XFS_DIR3_FT_BLKDEV;
case S_IFIFO:
return XFS_DIR3_FT_FIFO;
case S_IFSOCK:
return XFS_DIR3_FT_SOCK;
case S_IFLNK:
return XFS_DIR3_FT_SYMLINK;
default:
return XFS_DIR3_FT_UNKNOWN;
}
}
/*
* ASCII case-insensitive (ie. A-Z) support for directories that was
* used in IRIX.
*/
xfs_dahash_t
xfs_ascii_ci_hashname(
const struct xfs_name *name)
{
xfs_dahash_t hash;
int i;
for (i = 0, hash = 0; i < name->len; i++)
hash = tolower(name->name[i]) ^ rol32(hash, 7);
return hash;
}
enum xfs_dacmp
xfs_ascii_ci_compname(
struct xfs_da_args *args,
const unsigned char *name,
int len)
{
enum xfs_dacmp result;
int i;
if (args->namelen != len)
return XFS_CMP_DIFFERENT;
result = XFS_CMP_EXACT;
for (i = 0; i < len; i++) {
if (args->name[i] == name[i])
continue;
if (tolower(args->name[i]) != tolower(name[i]))
return XFS_CMP_DIFFERENT;
result = XFS_CMP_CASE;
}
return result;
}
int
xfs_da_mount(
struct xfs_mount *mp)
{
struct xfs_da_geometry *dageo;
ASSERT(mp->m_sb.sb_versionnum & XFS_SB_VERSION_DIRV2BIT);
ASSERT(xfs_dir2_dirblock_bytes(&mp->m_sb) <= XFS_MAX_BLOCKSIZE);
mp->m_dir_geo = kmem_zalloc(sizeof(struct xfs_da_geometry),
KM_MAYFAIL);
mp->m_attr_geo = kmem_zalloc(sizeof(struct xfs_da_geometry),
KM_MAYFAIL);
if (!mp->m_dir_geo || !mp->m_attr_geo) {
kmem_free(mp->m_dir_geo);
kmem_free(mp->m_attr_geo);
return -ENOMEM;
}
/* set up directory geometry */
dageo = mp->m_dir_geo;
dageo->blklog = mp->m_sb.sb_blocklog + mp->m_sb.sb_dirblklog;
dageo->fsblog = mp->m_sb.sb_blocklog;
dageo->blksize = xfs_dir2_dirblock_bytes(&mp->m_sb);
dageo->fsbcount = 1 << mp->m_sb.sb_dirblklog;
if (xfs_has_crc(mp)) {
dageo->node_hdr_size = sizeof(struct xfs_da3_node_hdr);
dageo->leaf_hdr_size = sizeof(struct xfs_dir3_leaf_hdr);
dageo->free_hdr_size = sizeof(struct xfs_dir3_free_hdr);
dageo->data_entry_offset =
sizeof(struct xfs_dir3_data_hdr);
} else {
dageo->node_hdr_size = sizeof(struct xfs_da_node_hdr);
dageo->leaf_hdr_size = sizeof(struct xfs_dir2_leaf_hdr);
dageo->free_hdr_size = sizeof(struct xfs_dir2_free_hdr);
dageo->data_entry_offset =
sizeof(struct xfs_dir2_data_hdr);
}
dageo->leaf_max_ents = (dageo->blksize - dageo->leaf_hdr_size) /
sizeof(struct xfs_dir2_leaf_entry);
dageo->free_max_bests = (dageo->blksize - dageo->free_hdr_size) /
sizeof(xfs_dir2_data_off_t);
dageo->data_first_offset = dageo->data_entry_offset +
xfs_dir2_data_entsize(mp, 1) +
xfs_dir2_data_entsize(mp, 2);
/*
* Now we've set up the block conversion variables, we can calculate the
* segment block constants using the geometry structure.
*/
dageo->datablk = xfs_dir2_byte_to_da(dageo, XFS_DIR2_DATA_OFFSET);
dageo->leafblk = xfs_dir2_byte_to_da(dageo, XFS_DIR2_LEAF_OFFSET);
dageo->freeblk = xfs_dir2_byte_to_da(dageo, XFS_DIR2_FREE_OFFSET);
dageo->node_ents = (dageo->blksize - dageo->node_hdr_size) /
(uint)sizeof(xfs_da_node_entry_t);
dageo->magicpct = (dageo->blksize * 37) / 100;
/* set up attribute geometry - single fsb only */
dageo = mp->m_attr_geo;
dageo->blklog = mp->m_sb.sb_blocklog;
dageo->fsblog = mp->m_sb.sb_blocklog;
dageo->blksize = 1 << dageo->blklog;
dageo->fsbcount = 1;
dageo->node_hdr_size = mp->m_dir_geo->node_hdr_size;
dageo->node_ents = (dageo->blksize - dageo->node_hdr_size) /
(uint)sizeof(xfs_da_node_entry_t);
dageo->magicpct = (dageo->blksize * 37) / 100;
return 0;
}
void
xfs_da_unmount(
struct xfs_mount *mp)
{
kmem_free(mp->m_dir_geo);
kmem_free(mp->m_attr_geo);
}
/*
* Return 1 if directory contains only "." and "..".
*/
int
xfs_dir_isempty(
xfs_inode_t *dp)
{
xfs_dir2_sf_hdr_t *sfp;
ASSERT(S_ISDIR(VFS_I(dp)->i_mode));
if (dp->i_disk_size == 0) /* might happen during shutdown. */
return 1;
if (dp->i_disk_size > XFS_IFORK_DSIZE(dp))
return 0;
sfp = (xfs_dir2_sf_hdr_t *)dp->i_df.if_u1.if_data;
return !sfp->count;
}
/*
* Validate a given inode number.
*/
int
xfs_dir_ino_validate(
xfs_mount_t *mp,
xfs_ino_t ino)
{
bool ino_ok = xfs_verify_dir_ino(mp, ino);
if (XFS_IS_CORRUPT(mp, !ino_ok) ||
XFS_TEST_ERROR(false, mp, XFS_ERRTAG_DIR_INO_VALIDATE)) {
xfs_warn(mp, "Invalid inode number 0x%Lx",
(unsigned long long) ino);
return -EFSCORRUPTED;
}
return 0;
}
/*
* Initialize a directory with its "." and ".." entries.
*/
int
xfs_dir_init(
xfs_trans_t *tp,
xfs_inode_t *dp,
xfs_inode_t *pdp)
{
struct xfs_da_args *args;
int error;
ASSERT(S_ISDIR(VFS_I(dp)->i_mode));
error = xfs_dir_ino_validate(tp->t_mountp, pdp->i_ino);
if (error)
return error;
args = kmem_zalloc(sizeof(*args), KM_NOFS);
if (!args)
return -ENOMEM;
args->geo = dp->i_mount->m_dir_geo;
args->dp = dp;
args->trans = tp;
error = xfs_dir2_sf_create(args, pdp->i_ino);
kmem_free(args);
return error;
}
/*
* Enter a name in a directory, or check for available space.
* If inum is 0, only the available space test is performed.
*/
int
xfs_dir_createname(
struct xfs_trans *tp,
struct xfs_inode *dp,
const struct xfs_name *name,
xfs_ino_t inum, /* new entry inode number */
xfs_extlen_t total) /* bmap's total block count */
{
struct xfs_da_args *args;
int rval;
int v; /* type-checking value */
ASSERT(S_ISDIR(VFS_I(dp)->i_mode));
if (inum) {
rval = xfs_dir_ino_validate(tp->t_mountp, inum);
if (rval)
return rval;
XFS_STATS_INC(dp->i_mount, xs_dir_create);
}
args = kmem_zalloc(sizeof(*args), KM_NOFS);
if (!args)
return -ENOMEM;
args->geo = dp->i_mount->m_dir_geo;
args->name = name->name;
args->namelen = name->len;
args->filetype = name->type;
args->hashval = xfs_dir2_hashname(dp->i_mount, name);
args->inumber = inum;
args->dp = dp;
args->total = total;
args->whichfork = XFS_DATA_FORK;
args->trans = tp;
args->op_flags = XFS_DA_OP_ADDNAME | XFS_DA_OP_OKNOENT;
if (!inum)
args->op_flags |= XFS_DA_OP_JUSTCHECK;
if (dp->i_df.if_format == XFS_DINODE_FMT_LOCAL) {
rval = xfs_dir2_sf_addname(args);
goto out_free;
}
rval = xfs_dir2_isblock(args, &v);
if (rval)
goto out_free;
if (v) {
rval = xfs_dir2_block_addname(args);
goto out_free;
}
rval = xfs_dir2_isleaf(args, &v);
if (rval)
goto out_free;
if (v)
rval = xfs_dir2_leaf_addname(args);
else
rval = xfs_dir2_node_addname(args);
out_free:
kmem_free(args);
return rval;
}
/*
* If doing a CI lookup and case-insensitive match, dup actual name into
* args.value. Return EEXIST for success (ie. name found) or an error.
*/
int
xfs_dir_cilookup_result(
struct xfs_da_args *args,
const unsigned char *name,
int len)
{
if (args->cmpresult == XFS_CMP_DIFFERENT)
return -ENOENT;
if (args->cmpresult != XFS_CMP_CASE ||
!(args->op_flags & XFS_DA_OP_CILOOKUP))
return -EEXIST;
args->value = kmem_alloc(len, KM_NOFS | KM_MAYFAIL);
if (!args->value)
return -ENOMEM;
memcpy(args->value, name, len);
args->valuelen = len;
return -EEXIST;
}
/*
* Lookup a name in a directory, give back the inode number.
* If ci_name is not NULL, returns the actual name in ci_name if it differs
* to name, or ci_name->name is set to NULL for an exact match.
*/
int
xfs_dir_lookup(
struct xfs_trans *tp,
struct xfs_inode *dp,
const struct xfs_name *name,
xfs_ino_t *inum, /* out: inode number */
struct xfs_name *ci_name) /* out: actual name if CI match */
{
struct xfs_da_args *args;
int rval;
int v; /* type-checking value */
int lock_mode;
ASSERT(S_ISDIR(VFS_I(dp)->i_mode));
XFS_STATS_INC(dp->i_mount, xs_dir_lookup);
/*
* We need to use KM_NOFS here so that lockdep will not throw false
* positive deadlock warnings on a non-transactional lookup path. It is
* safe to recurse into inode recalim in that case, but lockdep can't
* easily be taught about it. Hence KM_NOFS avoids having to add more
* lockdep Doing this avoids having to add a bunch of lockdep class
* annotations into the reclaim path for the ilock.
*/
args = kmem_zalloc(sizeof(*args), KM_NOFS);
args->geo = dp->i_mount->m_dir_geo;
args->name = name->name;
args->namelen = name->len;
args->filetype = name->type;
args->hashval = xfs_dir2_hashname(dp->i_mount, name);
args->dp = dp;
args->whichfork = XFS_DATA_FORK;
args->trans = tp;
args->op_flags = XFS_DA_OP_OKNOENT;
if (ci_name)
args->op_flags |= XFS_DA_OP_CILOOKUP;
lock_mode = xfs_ilock_data_map_shared(dp);
if (dp->i_df.if_format == XFS_DINODE_FMT_LOCAL) {
rval = xfs_dir2_sf_lookup(args);
goto out_check_rval;
}
rval = xfs_dir2_isblock(args, &v);
if (rval)
goto out_free;
if (v) {
rval = xfs_dir2_block_lookup(args);
goto out_check_rval;
}
rval = xfs_dir2_isleaf(args, &v);
if (rval)
goto out_free;
if (v)
rval = xfs_dir2_leaf_lookup(args);
else
rval = xfs_dir2_node_lookup(args);
out_check_rval:
if (rval == -EEXIST)
rval = 0;
if (!rval) {
*inum = args->inumber;
if (ci_name) {
ci_name->name = args->value;
ci_name->len = args->valuelen;
}
}
out_free:
xfs_iunlock(dp, lock_mode);
kmem_free(args);
return rval;
}
/*
* Remove an entry from a directory.
*/
int
xfs_dir_removename(
struct xfs_trans *tp,
struct xfs_inode *dp,
struct xfs_name *name,
xfs_ino_t ino,
xfs_extlen_t total) /* bmap's total block count */
{
struct xfs_da_args *args;
int rval;
int v; /* type-checking value */
ASSERT(S_ISDIR(VFS_I(dp)->i_mode));
XFS_STATS_INC(dp->i_mount, xs_dir_remove);
args = kmem_zalloc(sizeof(*args), KM_NOFS);
if (!args)
return -ENOMEM;
args->geo = dp->i_mount->m_dir_geo;
args->name = name->name;
args->namelen = name->len;
args->filetype = name->type;
args->hashval = xfs_dir2_hashname(dp->i_mount, name);
args->inumber = ino;
args->dp = dp;
args->total = total;
args->whichfork = XFS_DATA_FORK;
args->trans = tp;
if (dp->i_df.if_format == XFS_DINODE_FMT_LOCAL) {
rval = xfs_dir2_sf_removename(args);
goto out_free;
}
rval = xfs_dir2_isblock(args, &v);
if (rval)
goto out_free;
if (v) {
rval = xfs_dir2_block_removename(args);
goto out_free;
}
rval = xfs_dir2_isleaf(args, &v);
if (rval)
goto out_free;
if (v)
rval = xfs_dir2_leaf_removename(args);
else
rval = xfs_dir2_node_removename(args);
out_free:
kmem_free(args);
return rval;
}
/*
* Replace the inode number of a directory entry.
*/
int
xfs_dir_replace(
struct xfs_trans *tp,
struct xfs_inode *dp,
const struct xfs_name *name, /* name of entry to replace */
xfs_ino_t inum, /* new inode number */
xfs_extlen_t total) /* bmap's total block count */
{
struct xfs_da_args *args;
int rval;
int v; /* type-checking value */
ASSERT(S_ISDIR(VFS_I(dp)->i_mode));
rval = xfs_dir_ino_validate(tp->t_mountp, inum);
if (rval)
return rval;
args = kmem_zalloc(sizeof(*args), KM_NOFS);
if (!args)
return -ENOMEM;
args->geo = dp->i_mount->m_dir_geo;
args->name = name->name;
args->namelen = name->len;
args->filetype = name->type;
args->hashval = xfs_dir2_hashname(dp->i_mount, name);
args->inumber = inum;
args->dp = dp;
args->total = total;
args->whichfork = XFS_DATA_FORK;
args->trans = tp;
if (dp->i_df.if_format == XFS_DINODE_FMT_LOCAL) {
rval = xfs_dir2_sf_replace(args);
goto out_free;
}
rval = xfs_dir2_isblock(args, &v);
if (rval)
goto out_free;
if (v) {
rval = xfs_dir2_block_replace(args);
goto out_free;
}
rval = xfs_dir2_isleaf(args, &v);
if (rval)
goto out_free;
if (v)
rval = xfs_dir2_leaf_replace(args);
else
rval = xfs_dir2_node_replace(args);
out_free:
kmem_free(args);
return rval;
}
/*
* See if this entry can be added to the directory without allocating space.
*/
int
xfs_dir_canenter(
xfs_trans_t *tp,
xfs_inode_t *dp,
struct xfs_name *name) /* name of entry to add */
{
return xfs_dir_createname(tp, dp, name, 0, 0);
}
/*
* Utility routines.
*/
/*
* Add a block to the directory.
*
* This routine is for data and free blocks, not leaf/node blocks which are
* handled by xfs_da_grow_inode.
*/
int
xfs_dir2_grow_inode(
struct xfs_da_args *args,
int space, /* v2 dir's space XFS_DIR2_xxx_SPACE */
xfs_dir2_db_t *dbp) /* out: block number added */
{
struct xfs_inode *dp = args->dp;
struct xfs_mount *mp = dp->i_mount;
xfs_fileoff_t bno; /* directory offset of new block */
int count; /* count of filesystem blocks */
int error;
trace_xfs_dir2_grow_inode(args, space);
/*
* Set lowest possible block in the space requested.
*/
bno = XFS_B_TO_FSBT(mp, space * XFS_DIR2_SPACE_SIZE);
count = args->geo->fsbcount;
error = xfs_da_grow_inode_int(args, &bno, count);
if (error)
return error;
*dbp = xfs_dir2_da_to_db(args->geo, (xfs_dablk_t)bno);
/*
* Update file's size if this is the data space and it grew.
*/
if (space == XFS_DIR2_DATA_SPACE) {
xfs_fsize_t size; /* directory file (data) size */
size = XFS_FSB_TO_B(mp, bno + count);
if (size > dp->i_disk_size) {
dp->i_disk_size = size;
xfs_trans_log_inode(args->trans, dp, XFS_ILOG_CORE);
}
}
return 0;
}
/*
* See if the directory is a single-block form directory.
*/
int
xfs_dir2_isblock(
struct xfs_da_args *args,
int *vp) /* out: 1 is block, 0 is not block */
{
xfs_fileoff_t last; /* last file offset */
int rval;
if ((rval = xfs_bmap_last_offset(args->dp, &last, XFS_DATA_FORK)))
return rval;
rval = XFS_FSB_TO_B(args->dp->i_mount, last) == args->geo->blksize;
if (XFS_IS_CORRUPT(args->dp->i_mount,
rval != 0 &&
args->dp->i_disk_size != args->geo->blksize))
return -EFSCORRUPTED;
*vp = rval;
return 0;
}
/*
* See if the directory is a single-leaf form directory.
*/
int
xfs_dir2_isleaf(
struct xfs_da_args *args,
int *vp) /* out: 1 is block, 0 is not block */
{
xfs_fileoff_t last; /* last file offset */
int rval;
if ((rval = xfs_bmap_last_offset(args->dp, &last, XFS_DATA_FORK)))
return rval;
*vp = last == args->geo->leafblk + args->geo->fsbcount;
return 0;
}
/*
* Remove the given block from the directory.
* This routine is used for data and free blocks, leaf/node are done
* by xfs_da_shrink_inode.
*/
int
xfs_dir2_shrink_inode(
struct xfs_da_args *args,
xfs_dir2_db_t db,
struct xfs_buf *bp)
{
xfs_fileoff_t bno; /* directory file offset */
xfs_dablk_t da; /* directory file offset */
int done; /* bunmap is finished */
struct xfs_inode *dp;
int error;
struct xfs_mount *mp;
struct xfs_trans *tp;
trace_xfs_dir2_shrink_inode(args, db);
dp = args->dp;
mp = dp->i_mount;
tp = args->trans;
da = xfs_dir2_db_to_da(args->geo, db);
/* Unmap the fsblock(s). */
error = xfs_bunmapi(tp, dp, da, args->geo->fsbcount, 0, 0, &done);
if (error) {
/*
* ENOSPC actually can happen if we're in a removename with no
* space reservation, and the resulting block removal would
* cause a bmap btree split or conversion from extents to btree.
* This can only happen for un-fragmented directory blocks,
* since you need to be punching out the middle of an extent.
* In this case we need to leave the block in the file, and not
* binval it. So the block has to be in a consistent empty
* state and appropriately logged. We don't free up the buffer,
* the caller can tell it hasn't happened since it got an error
* back.
*/
return error;
}
ASSERT(done);
/*
* Invalidate the buffer from the transaction.
*/
xfs_trans_binval(tp, bp);
/*
* If it's not a data block, we're done.
*/
if (db >= xfs_dir2_byte_to_db(args->geo, XFS_DIR2_LEAF_OFFSET))
return 0;
/*
* If the block isn't the last one in the directory, we're done.
*/
if (dp->i_disk_size > xfs_dir2_db_off_to_byte(args->geo, db + 1, 0))
return 0;
bno = da;
if ((error = xfs_bmap_last_before(tp, dp, &bno, XFS_DATA_FORK))) {
/*
* This can't really happen unless there's kernel corruption.
*/
return error;
}
if (db == args->geo->datablk)
ASSERT(bno == 0);
else
ASSERT(bno > 0);
/*
* Set the size to the new last block.
*/
dp->i_disk_size = XFS_FSB_TO_B(mp, bno);
xfs_trans_log_inode(tp, dp, XFS_ILOG_CORE);
return 0;
}
/* Returns true if the directory entry name is valid. */
bool
xfs_dir2_namecheck(
const void *name,
size_t length)
{
/*
* MAXNAMELEN includes the trailing null, but (name/length) leave it
* out, so use >= for the length check.
*/
if (length >= MAXNAMELEN)
return false;
/* There shouldn't be any slashes or nulls here */
return !memchr(name, '/', length) && !memchr(name, 0, length);
}
xfs_dahash_t
xfs_dir2_hashname(
struct xfs_mount *mp,
const struct xfs_name *name)
{
if (unlikely(xfs_has_asciici(mp)))
return xfs_ascii_ci_hashname(name);
return xfs_da_hashname(name->name, name->len);
}
enum xfs_dacmp
xfs_dir2_compname(
struct xfs_da_args *args,
const unsigned char *name,
int len)
{
if (unlikely(xfs_has_asciici(args->dp->i_mount)))
return xfs_ascii_ci_compname(args, name, len);
return xfs_da_compname(args, name, len);
}