- 根目录:
- fs
- xfs
- xfs_dir2.c
/*
* Copyright (c) 2000-2001,2005 Silicon Graphics, Inc.
* All Rights Reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it would be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "xfs.h"
#include "xfs_fs.h"
#include "xfs_types.h"
#include "xfs_bit.h"
#include "xfs_log.h"
#include "xfs_inum.h"
#include "xfs_trans.h"
#include "xfs_sb.h"
#include "xfs_ag.h"
#include "xfs_dir2.h"
#include "xfs_mount.h"
#include "xfs_da_btree.h"
#include "xfs_bmap_btree.h"
#include "xfs_alloc_btree.h"
#include "xfs_dir2_sf.h"
#include "xfs_dinode.h"
#include "xfs_inode.h"
#include "xfs_inode_item.h"
#include "xfs_bmap.h"
#include "xfs_dir2_data.h"
#include "xfs_dir2_leaf.h"
#include "xfs_dir2_block.h"
#include "xfs_dir2_node.h"
#include "xfs_error.h"
#include "xfs_vnodeops.h"
#include "xfs_trace.h"
struct xfs_name xfs_name_dotdot = { (unsigned char *)"..", 2};
/*
* ASCII case-insensitive (ie. A-Z) support for directories that was
* used in IRIX.
*/
STATIC xfs_dahash_t
xfs_ascii_ci_hashname(
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;
}
STATIC 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;
}
static struct xfs_nameops xfs_ascii_ci_nameops = {
.hashname = xfs_ascii_ci_hashname,
.compname = xfs_ascii_ci_compname,
};
void
xfs_dir_mount(
xfs_mount_t *mp)
{
ASSERT(xfs_sb_version_hasdirv2(&mp->m_sb));
ASSERT((1 << (mp->m_sb.sb_blocklog + mp->m_sb.sb_dirblklog)) <=
XFS_MAX_BLOCKSIZE);
mp->m_dirblksize = 1 << (mp->m_sb.sb_blocklog + mp->m_sb.sb_dirblklog);
mp->m_dirblkfsbs = 1 << mp->m_sb.sb_dirblklog;
mp->m_dirdatablk = xfs_dir2_db_to_da(mp, XFS_DIR2_DATA_FIRSTDB(mp));
mp->m_dirleafblk = xfs_dir2_db_to_da(mp, XFS_DIR2_LEAF_FIRSTDB(mp));
mp->m_dirfreeblk = xfs_dir2_db_to_da(mp, XFS_DIR2_FREE_FIRSTDB(mp));
mp->m_attr_node_ents =
(mp->m_sb.sb_blocksize - (uint)sizeof(xfs_da_node_hdr_t)) /
(uint)sizeof(xfs_da_node_entry_t);
mp->m_dir_node_ents =
(mp->m_dirblksize - (uint)sizeof(xfs_da_node_hdr_t)) /
(uint)sizeof(xfs_da_node_entry_t);
mp->m_dir_magicpct = (mp->m_dirblksize * 37) / 100;
if (xfs_sb_version_hasasciici(&mp->m_sb))
mp->m_dirnameops = &xfs_ascii_ci_nameops;
else
mp->m_dirnameops = &xfs_default_nameops;
}
/*
* Return 1 if directory contains only "." and "..".
*/
int
xfs_dir_isempty(
xfs_inode_t *dp)
{
xfs_dir2_sf_t *sfp;
ASSERT((dp->i_d.di_mode & S_IFMT) == S_IFDIR);
if (dp->i_d.di_size == 0) /* might happen during shutdown. */
return 1;
if (dp->i_d.di_size > XFS_IFORK_DSIZE(dp))
return 0;
sfp = (xfs_dir2_sf_t *)dp->i_df.if_u1.if_data;
return !sfp->hdr.count;
}
/*
* Validate a given inode number.
*/
int
xfs_dir_ino_validate(
xfs_mount_t *mp,
xfs_ino_t ino)
{
xfs_agblock_t agblkno;
xfs_agino_t agino;
xfs_agnumber_t agno;
int ino_ok;
int ioff;
agno = XFS_INO_TO_AGNO(mp, ino);
agblkno = XFS_INO_TO_AGBNO(mp, ino);
ioff = XFS_INO_TO_OFFSET(mp, ino);
agino = XFS_OFFBNO_TO_AGINO(mp, agblkno, ioff);
ino_ok =
agno < mp->m_sb.sb_agcount &&
agblkno < mp->m_sb.sb_agblocks &&
agblkno != 0 &&
ioff < (1 << mp->m_sb.sb_inopblog) &&
XFS_AGINO_TO_INO(mp, agno, agino) == ino;
if (unlikely(XFS_TEST_ERROR(!ino_ok, mp, XFS_ERRTAG_DIR_INO_VALIDATE,
XFS_RANDOM_DIR_INO_VALIDATE))) {
xfs_warn(mp, "Invalid inode number 0x%Lx",
(unsigned long long) ino);
XFS_ERROR_REPORT("xfs_dir_ino_validate", XFS_ERRLEVEL_LOW, mp);
return XFS_ERROR(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)
{
xfs_da_args_t args;
int error;
memset((char *)&args, 0, sizeof(args));
args.dp = dp;
args.trans = tp;
ASSERT((dp->i_d.di_mode & S_IFMT) == S_IFDIR);
if ((error = xfs_dir_ino_validate(tp->t_mountp, pdp->i_ino)))
return error;
return xfs_dir2_sf_create(&args, pdp->i_ino);
}
/*
Enter a name in a directory.
*/
int
xfs_dir_createname(
xfs_trans_t *tp,
xfs_inode_t *dp,
struct xfs_name *name,
xfs_ino_t inum, /* new entry inode number */
xfs_fsblock_t *first, /* bmap's firstblock */
xfs_bmap_free_t *flist, /* bmap's freeblock list */
xfs_extlen_t total) /* bmap's total block count */
{
xfs_da_args_t args;
int rval;
int v; /* type-checking value */
ASSERT((dp->i_d.di_mode & S_IFMT) == S_IFDIR);
if ((rval = xfs_dir_ino_validate(tp->t_mountp, inum)))
return rval;
XFS_STATS_INC(xs_dir_create);
memset(&args, 0, sizeof(xfs_da_args_t));
args.name = name->name;
args.namelen = name->len;
args.hashval = dp->i_mount->m_dirnameops->hashname(name);
args.inumber = inum;
args.dp = dp;
args.firstblock = first;
args.flist = flist;
args.total = total;
args.whichfork = XFS_DATA_FORK;
args.trans = tp;
args.op_flags = XFS_DA_OP_ADDNAME | XFS_DA_OP_OKNOENT;
if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL)
rval = xfs_dir2_sf_addname(&args);
else if ((rval = xfs_dir2_isblock(tp, dp, &v)))
return rval;
else if (v)
rval = xfs_dir2_block_addname(&args);
else if ((rval = xfs_dir2_isleaf(tp, dp, &v)))
return rval;
else if (v)
rval = xfs_dir2_leaf_addname(&args);
else
rval = xfs_dir2_node_addname(&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(
xfs_trans_t *tp,
xfs_inode_t *dp,
struct xfs_name *name,
xfs_ino_t *inum, /* out: inode number */
struct xfs_name *ci_name) /* out: actual name if CI match */
{
xfs_da_args_t args;
int rval;
int v; /* type-checking value */
ASSERT((dp->i_d.di_mode & S_IFMT) == S_IFDIR);
XFS_STATS_INC(xs_dir_lookup);
memset(&args, 0, sizeof(xfs_da_args_t));
args.name = name->name;
args.namelen = name->len;
args.hashval = dp->i_mount->m_dirnameops->hashname(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;
if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL)
rval = xfs_dir2_sf_lookup(&args);
else if ((rval = xfs_dir2_isblock(tp, dp, &v)))
return rval;
else if (v)
rval = xfs_dir2_block_lookup(&args);
else if ((rval = xfs_dir2_isleaf(tp, dp, &v)))
return rval;
else if (v)
rval = xfs_dir2_leaf_lookup(&args);
else
rval = xfs_dir2_node_lookup(&args);
if (rval == EEXIST)
rval = 0;
if (!rval) {
*inum = args.inumber;
if (ci_name) {
ci_name->name = args.value;
ci_name->len = args.valuelen;
}
}
return rval;
}
/*
* Remove an entry from a directory.
*/
int
xfs_dir_removename(
xfs_trans_t *tp,
xfs_inode_t *dp,
struct xfs_name *name,
xfs_ino_t ino,
xfs_fsblock_t *first, /* bmap's firstblock */
xfs_bmap_free_t *flist, /* bmap's freeblock list */
xfs_extlen_t total) /* bmap's total block count */
{
xfs_da_args_t args;
int rval;
int v; /* type-checking value */
ASSERT((dp->i_d.di_mode & S_IFMT) == S_IFDIR);
XFS_STATS_INC(xs_dir_remove);
memset(&args, 0, sizeof(xfs_da_args_t));
args.name = name->name;
args.namelen = name->len;
args.hashval = dp->i_mount->m_dirnameops->hashname(name);
args.inumber = ino;
args.dp = dp;
args.firstblock = first;
args.flist = flist;
args.total = total;
args.whichfork = XFS_DATA_FORK;
args.trans = tp;
if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL)
rval = xfs_dir2_sf_removename(&args);
else if ((rval = xfs_dir2_isblock(tp, dp, &v)))
return rval;
else if (v)
rval = xfs_dir2_block_removename(&args);
else if ((rval = xfs_dir2_isleaf(tp, dp, &v)))
return rval;
else if (v)
rval = xfs_dir2_leaf_removename(&args);
else
rval = xfs_dir2_node_removename(&args);
return rval;
}
/*
* Read a directory.
*/
int
xfs_readdir(
xfs_inode_t *dp,
void *dirent,
size_t bufsize,
xfs_off_t *offset,
filldir_t filldir)
{
int rval; /* return value */
int v; /* type-checking value */
trace_xfs_readdir(dp);
if (XFS_FORCED_SHUTDOWN(dp->i_mount))
return XFS_ERROR(EIO);
ASSERT((dp->i_d.di_mode & S_IFMT) == S_IFDIR);
XFS_STATS_INC(xs_dir_getdents);
if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL)
rval = xfs_dir2_sf_getdents(dp, dirent, offset, filldir);
else if ((rval = xfs_dir2_isblock(NULL, dp, &v)))
;
else if (v)
rval = xfs_dir2_block_getdents(dp, dirent, offset, filldir);
else
rval = xfs_dir2_leaf_getdents(dp, dirent, bufsize, offset,
filldir);
return rval;
}
/*
* Replace the inode number of a directory entry.
*/
int
xfs_dir_replace(
xfs_trans_t *tp,
xfs_inode_t *dp,
struct xfs_name *name, /* name of entry to replace */
xfs_ino_t inum, /* new inode number */
xfs_fsblock_t *first, /* bmap's firstblock */
xfs_bmap_free_t *flist, /* bmap's freeblock list */
xfs_extlen_t total) /* bmap's total block count */
{
xfs_da_args_t args;
int rval;
int v; /* type-checking value */
ASSERT((dp->i_d.di_mode & S_IFMT) == S_IFDIR);
if ((rval = xfs_dir_ino_validate(tp->t_mountp, inum)))
return rval;
memset(&args, 0, sizeof(xfs_da_args_t));
args.name = name->name;
args.namelen = name->len;
args.hashval = dp->i_mount->m_dirnameops->hashname(name);
args.inumber = inum;
args.dp = dp;
args.firstblock = first;
args.flist = flist;
args.total = total;
args.whichfork = XFS_DATA_FORK;
args.trans = tp;
if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL)
rval = xfs_dir2_sf_replace(&args);
else if ((rval = xfs_dir2_isblock(tp, dp, &v)))
return rval;
else if (v)
rval = xfs_dir2_block_replace(&args);
else if ((rval = xfs_dir2_isleaf(tp, dp, &v)))
return rval;
else if (v)
rval = xfs_dir2_leaf_replace(&args);
else
rval = xfs_dir2_node_replace(&args);
return rval;
}
/*
* See if this entry can be added to the directory without allocating space.
* First checks that the caller couldn't reserve enough space (resblks = 0).
*/
int
xfs_dir_canenter(
xfs_trans_t *tp,
xfs_inode_t *dp,
struct xfs_name *name, /* name of entry to add */
uint resblks)
{
xfs_da_args_t args;
int rval;
int v; /* type-checking value */
if (resblks)
return 0;
ASSERT((dp->i_d.di_mode & S_IFMT) == S_IFDIR);
memset(&args, 0, sizeof(xfs_da_args_t));
args.name = name->name;
args.namelen = name->len;
args.hashval = dp->i_mount->m_dirnameops->hashname(name);
args.dp = dp;
args.whichfork = XFS_DATA_FORK;
args.trans = tp;
args.op_flags = XFS_DA_OP_JUSTCHECK | XFS_DA_OP_ADDNAME |
XFS_DA_OP_OKNOENT;
if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL)
rval = xfs_dir2_sf_addname(&args);
else if ((rval = xfs_dir2_isblock(tp, dp, &v)))
return rval;
else if (v)
rval = xfs_dir2_block_addname(&args);
else if ((rval = xfs_dir2_isleaf(tp, dp, &v)))
return rval;
else if (v)
rval = xfs_dir2_leaf_addname(&args);
else
rval = xfs_dir2_node_addname(&args);
return rval;
}
/*
* 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(
xfs_da_args_t *args,
int space, /* v2 dir's space XFS_DIR2_xxx_SPACE */
xfs_dir2_db_t *dbp) /* out: block number added */
{
xfs_fileoff_t bno; /* directory offset of new block */
int count; /* count of filesystem blocks */
xfs_inode_t *dp; /* incore directory inode */
int error;
int got; /* blocks actually mapped */
int i;
xfs_bmbt_irec_t map; /* single structure for bmap */
int mapi; /* mapping index */
xfs_bmbt_irec_t *mapp; /* bmap mapping structure(s) */
xfs_mount_t *mp;
int nmap; /* number of bmap entries */
xfs_trans_t *tp;
xfs_drfsbno_t nblks;
trace_xfs_dir2_grow_inode(args, space);
dp = args->dp;
tp = args->trans;
mp = dp->i_mount;
nblks = dp->i_d.di_nblocks;
/*
* Set lowest possible block in the space requested.
*/
bno = XFS_B_TO_FSBT(mp, space * XFS_DIR2_SPACE_SIZE);
count = mp->m_dirblkfsbs;
/*
* Find the first hole for our block.
*/
if ((error = xfs_bmap_first_unused(tp, dp, count, &bno, XFS_DATA_FORK)))
return error;
nmap = 1;
ASSERT(args->firstblock != NULL);
/*
* Try mapping the new block contiguously (one extent).
*/
if ((error = xfs_bmapi(tp, dp, bno, count,
XFS_BMAPI_WRITE|XFS_BMAPI_METADATA|XFS_BMAPI_CONTIG,
args->firstblock, args->total, &map, &nmap,
args->flist)))
return error;
ASSERT(nmap <= 1);
if (nmap == 1) {
mapp = ↦
mapi = 1;
}
/*
* Didn't work and this is a multiple-fsb directory block.
* Try again with contiguous flag turned on.
*/
else if (nmap == 0 && count > 1) {
xfs_fileoff_t b; /* current file offset */
/*
* Space for maximum number of mappings.
*/
mapp = kmem_alloc(sizeof(*mapp) * count, KM_SLEEP);
/*
* Iterate until we get to the end of our block.
*/
for (b = bno, mapi = 0; b < bno + count; ) {
int c; /* current fsb count */
/*
* Can't map more than MAX_NMAP at once.
*/
nmap = MIN(XFS_BMAP_MAX_NMAP, count);
c = (int)(bno + count - b);
if ((error = xfs_bmapi(tp, dp, b, c,
XFS_BMAPI_WRITE|XFS_BMAPI_METADATA,
args->firstblock, args->total,
&mapp[mapi], &nmap, args->flist))) {
kmem_free(mapp);
return error;
}
if (nmap < 1)
break;
/*
* Add this bunch into our table, go to the next offset.
*/
mapi += nmap;
b = mapp[mapi - 1].br_startoff +
mapp[mapi - 1].br_blockcount;
}
}
/*
* Didn't work.
*/
else {
mapi = 0;
mapp = NULL;
}
/*
* See how many fsb's we got.
*/
for (i = 0, got = 0; i < mapi; i++)
got += mapp[i].br_blockcount;
/*
* Didn't get enough fsb's, or the first/last block's are wrong.
*/
if (got != count || mapp[0].br_startoff != bno ||
mapp[mapi - 1].br_startoff + mapp[mapi - 1].br_blockcount !=
bno + count) {
if (mapp != &map)
kmem_free(mapp);
return XFS_ERROR(ENOSPC);
}
/*
* Done with the temporary mapping table.
*/
if (mapp != &map)
kmem_free(mapp);
/* account for newly allocated blocks in reserved blocks total */
args->total -= dp->i_d.di_nblocks - nblks;
*dbp = xfs_dir2_da_to_db(mp, (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_d.di_size) {
dp->i_d.di_size = size;
xfs_trans_log_inode(tp, dp, XFS_ILOG_CORE);
}
}
return 0;
}
/*
* See if the directory is a single-block form directory.
*/
int
xfs_dir2_isblock(
xfs_trans_t *tp,
xfs_inode_t *dp,
int *vp) /* out: 1 is block, 0 is not block */
{
xfs_fileoff_t last; /* last file offset */
xfs_mount_t *mp;
int rval;
mp = dp->i_mount;
if ((rval = xfs_bmap_last_offset(tp, dp, &last, XFS_DATA_FORK)))
return rval;
rval = XFS_FSB_TO_B(mp, last) == mp->m_dirblksize;
ASSERT(rval == 0 || dp->i_d.di_size == mp->m_dirblksize);
*vp = rval;
return 0;
}
/*
* See if the directory is a single-leaf form directory.
*/
int
xfs_dir2_isleaf(
xfs_trans_t *tp,
xfs_inode_t *dp,
int *vp) /* out: 1 is leaf, 0 is not leaf */
{
xfs_fileoff_t last; /* last file offset */
xfs_mount_t *mp;
int rval;
mp = dp->i_mount;
if ((rval = xfs_bmap_last_offset(tp, dp, &last, XFS_DATA_FORK)))
return rval;
*vp = last == mp->m_dirleafblk + (1 << mp->m_sb.sb_dirblklog);
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(
xfs_da_args_t *args,
xfs_dir2_db_t db,
xfs_dabuf_t *bp)
{
xfs_fileoff_t bno; /* directory file offset */
xfs_dablk_t da; /* directory file offset */
int done; /* bunmap is finished */
xfs_inode_t *dp;
int error;
xfs_mount_t *mp;
xfs_trans_t *tp;
trace_xfs_dir2_shrink_inode(args, db);
dp = args->dp;
mp = dp->i_mount;
tp = args->trans;
da = xfs_dir2_db_to_da(mp, db);
/*
* Unmap the fsblock(s).
*/
if ((error = xfs_bunmapi(tp, dp, da, mp->m_dirblkfsbs,
XFS_BMAPI_METADATA, 0, args->firstblock, args->flist,
&done))) {
/*
* 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_da_binval(tp, bp);
/*
* If it's not a data block, we're done.
*/
if (db >= XFS_DIR2_LEAF_FIRSTDB(mp))
return 0;
/*
* If the block isn't the last one in the directory, we're done.
*/
if (dp->i_d.di_size > xfs_dir2_db_off_to_byte(mp, 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 == mp->m_dirdatablk)
ASSERT(bno == 0);
else
ASSERT(bno > 0);
/*
* Set the size to the new last block.
*/
dp->i_d.di_size = XFS_FSB_TO_B(mp, bno);
xfs_trans_log_inode(tp, dp, XFS_ILOG_CORE);
return 0;
}