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xfs_dir2_block.c
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xfs_dir2_block.c
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/*
* Copyright (c) 2000-2003,2005 Silicon Graphics, Inc.
* Copyright (c) 2013 Red Hat, 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_log.h"
#include "xfs_trans.h"
#include "xfs_sb.h"
#include "xfs_ag.h"
#include "xfs_mount.h"
#include "xfs_da_btree.h"
#include "xfs_bmap_btree.h"
#include "xfs_dinode.h"
#include "xfs_inode.h"
#include "xfs_inode_item.h"
#include "xfs_bmap.h"
#include "xfs_buf_item.h"
#include "xfs_dir2.h"
#include "xfs_dir2_format.h"
#include "xfs_dir2_priv.h"
#include "xfs_error.h"
#include "xfs_trace.h"
#include "xfs_cksum.h"
/*
* Local function prototypes.
*/
static void xfs_dir2_block_log_leaf(xfs_trans_t *tp, struct xfs_buf *bp,
int first, int last);
static void xfs_dir2_block_log_tail(xfs_trans_t *tp, struct xfs_buf *bp);
static int xfs_dir2_block_lookup_int(xfs_da_args_t *args, struct xfs_buf **bpp,
int *entno);
static int xfs_dir2_block_sort(const void *a, const void *b);
static xfs_dahash_t xfs_dir_hash_dot, xfs_dir_hash_dotdot;
/*
* One-time startup routine called from xfs_init().
*/
void
xfs_dir_startup(void)
{
xfs_dir_hash_dot = xfs_da_hashname((unsigned char *)".", 1);
xfs_dir_hash_dotdot = xfs_da_hashname((unsigned char *)"..", 2);
}
static bool
xfs_dir3_block_verify(
struct xfs_buf *bp)
{
struct xfs_mount *mp = bp->b_target->bt_mount;
struct xfs_dir3_blk_hdr *hdr3 = bp->b_addr;
if (xfs_sb_version_hascrc(&mp->m_sb)) {
if (hdr3->magic != cpu_to_be32(XFS_DIR3_BLOCK_MAGIC))
return false;
if (!uuid_equal(&hdr3->uuid, &mp->m_sb.sb_uuid))
return false;
if (be64_to_cpu(hdr3->blkno) != bp->b_bn)
return false;
} else {
if (hdr3->magic != cpu_to_be32(XFS_DIR2_BLOCK_MAGIC))
return false;
}
if (__xfs_dir3_data_check(NULL, bp))
return false;
return true;
}
static void
xfs_dir3_block_read_verify(
struct xfs_buf *bp)
{
struct xfs_mount *mp = bp->b_target->bt_mount;
if ((xfs_sb_version_hascrc(&mp->m_sb) &&
!xfs_verify_cksum(bp->b_addr, BBTOB(bp->b_length),
XFS_DIR3_DATA_CRC_OFF)) ||
!xfs_dir3_block_verify(bp)) {
XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, bp->b_addr);
xfs_buf_ioerror(bp, EFSCORRUPTED);
}
}
static void
xfs_dir3_block_write_verify(
struct xfs_buf *bp)
{
struct xfs_mount *mp = bp->b_target->bt_mount;
struct xfs_buf_log_item *bip = bp->b_fspriv;
struct xfs_dir3_blk_hdr *hdr3 = bp->b_addr;
if (!xfs_dir3_block_verify(bp)) {
XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, bp->b_addr);
xfs_buf_ioerror(bp, EFSCORRUPTED);
return;
}
if (!xfs_sb_version_hascrc(&mp->m_sb))
return;
if (bip)
hdr3->lsn = cpu_to_be64(bip->bli_item.li_lsn);
xfs_update_cksum(bp->b_addr, BBTOB(bp->b_length), XFS_DIR3_DATA_CRC_OFF);
}
const struct xfs_buf_ops xfs_dir3_block_buf_ops = {
.verify_read = xfs_dir3_block_read_verify,
.verify_write = xfs_dir3_block_write_verify,
};
static int
xfs_dir3_block_read(
struct xfs_trans *tp,
struct xfs_inode *dp,
struct xfs_buf **bpp)
{
struct xfs_mount *mp = dp->i_mount;
int err;
err = xfs_da_read_buf(tp, dp, mp->m_dirdatablk, -1, bpp,
XFS_DATA_FORK, &xfs_dir3_block_buf_ops);
if (!err && tp)
xfs_trans_buf_set_type(tp, *bpp, XFS_BLFT_DIR_BLOCK_BUF);
return err;
}
static void
xfs_dir3_block_init(
struct xfs_mount *mp,
struct xfs_trans *tp,
struct xfs_buf *bp,
struct xfs_inode *dp)
{
struct xfs_dir3_blk_hdr *hdr3 = bp->b_addr;
bp->b_ops = &xfs_dir3_block_buf_ops;
xfs_trans_buf_set_type(tp, bp, XFS_BLFT_DIR_BLOCK_BUF);
if (xfs_sb_version_hascrc(&mp->m_sb)) {
memset(hdr3, 0, sizeof(*hdr3));
hdr3->magic = cpu_to_be32(XFS_DIR3_BLOCK_MAGIC);
hdr3->blkno = cpu_to_be64(bp->b_bn);
hdr3->owner = cpu_to_be64(dp->i_ino);
uuid_copy(&hdr3->uuid, &mp->m_sb.sb_uuid);
return;
}
hdr3->magic = cpu_to_be32(XFS_DIR2_BLOCK_MAGIC);
}
static void
xfs_dir2_block_need_space(
struct xfs_dir2_data_hdr *hdr,
struct xfs_dir2_block_tail *btp,
struct xfs_dir2_leaf_entry *blp,
__be16 **tagpp,
struct xfs_dir2_data_unused **dupp,
struct xfs_dir2_data_unused **enddupp,
int *compact,
int len)
{
struct xfs_dir2_data_free *bf;
__be16 *tagp = NULL;
struct xfs_dir2_data_unused *dup = NULL;
struct xfs_dir2_data_unused *enddup = NULL;
*compact = 0;
bf = xfs_dir3_data_bestfree_p(hdr);
/*
* If there are stale entries we'll use one for the leaf.
*/
if (btp->stale) {
if (be16_to_cpu(bf[0].length) >= len) {
/*
* The biggest entry enough to avoid compaction.
*/
dup = (xfs_dir2_data_unused_t *)
((char *)hdr + be16_to_cpu(bf[0].offset));
goto out;
}
/*
* Will need to compact to make this work.
* Tag just before the first leaf entry.
*/
*compact = 1;
tagp = (__be16 *)blp - 1;
/* Data object just before the first leaf entry. */
dup = (xfs_dir2_data_unused_t *)((char *)hdr + be16_to_cpu(*tagp));
/*
* If it's not free then the data will go where the
* leaf data starts now, if it works at all.
*/
if (be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG) {
if (be16_to_cpu(dup->length) + (be32_to_cpu(btp->stale) - 1) *
(uint)sizeof(*blp) < len)
dup = NULL;
} else if ((be32_to_cpu(btp->stale) - 1) * (uint)sizeof(*blp) < len)
dup = NULL;
else
dup = (xfs_dir2_data_unused_t *)blp;
goto out;
}
/*
* no stale entries, so just use free space.
* Tag just before the first leaf entry.
*/
tagp = (__be16 *)blp - 1;
/* Data object just before the first leaf entry. */
enddup = (xfs_dir2_data_unused_t *)((char *)hdr + be16_to_cpu(*tagp));
/*
* If it's not free then can't do this add without cleaning up:
* the space before the first leaf entry needs to be free so it
* can be expanded to hold the pointer to the new entry.
*/
if (be16_to_cpu(enddup->freetag) == XFS_DIR2_DATA_FREE_TAG) {
/*
* Check out the biggest freespace and see if it's the same one.
*/
dup = (xfs_dir2_data_unused_t *)
((char *)hdr + be16_to_cpu(bf[0].offset));
if (dup != enddup) {
/*
* Not the same free entry, just check its length.
*/
if (be16_to_cpu(dup->length) < len)
dup = NULL;
goto out;
}
/*
* It is the biggest freespace, can it hold the leaf too?
*/
if (be16_to_cpu(dup->length) < len + (uint)sizeof(*blp)) {
/*
* Yes, use the second-largest entry instead if it works.
*/
if (be16_to_cpu(bf[1].length) >= len)
dup = (xfs_dir2_data_unused_t *)
((char *)hdr + be16_to_cpu(bf[1].offset));
else
dup = NULL;
}
}
out:
*tagpp = tagp;
*dupp = dup;
*enddupp = enddup;
}
/*
* compact the leaf entries.
* Leave the highest-numbered stale entry stale.
* XXX should be the one closest to mid but mid is not yet computed.
*/
static void
xfs_dir2_block_compact(
struct xfs_trans *tp,
struct xfs_buf *bp,
struct xfs_dir2_data_hdr *hdr,
struct xfs_dir2_block_tail *btp,
struct xfs_dir2_leaf_entry *blp,
int *needlog,
int *lfloghigh,
int *lfloglow)
{
int fromidx; /* source leaf index */
int toidx; /* target leaf index */
int needscan = 0;
int highstale; /* high stale index */
fromidx = toidx = be32_to_cpu(btp->count) - 1;
highstale = *lfloghigh = -1;
for (; fromidx >= 0; fromidx--) {
if (blp[fromidx].address == cpu_to_be32(XFS_DIR2_NULL_DATAPTR)) {
if (highstale == -1)
highstale = toidx;
else {
if (*lfloghigh == -1)
*lfloghigh = toidx;
continue;
}
}
if (fromidx < toidx)
blp[toidx] = blp[fromidx];
toidx--;
}
*lfloglow = toidx + 1 - (be32_to_cpu(btp->stale) - 1);
*lfloghigh -= be32_to_cpu(btp->stale) - 1;
be32_add_cpu(&btp->count, -(be32_to_cpu(btp->stale) - 1));
xfs_dir2_data_make_free(tp, bp,
(xfs_dir2_data_aoff_t)((char *)blp - (char *)hdr),
(xfs_dir2_data_aoff_t)((be32_to_cpu(btp->stale) - 1) * sizeof(*blp)),
needlog, &needscan);
blp += be32_to_cpu(btp->stale) - 1;
btp->stale = cpu_to_be32(1);
/*
* If we now need to rebuild the bestfree map, do so.
* This needs to happen before the next call to use_free.
*/
if (needscan)
xfs_dir2_data_freescan(tp->t_mountp, hdr, needlog);
}
/*
* Add an entry to a block directory.
*/
int /* error */
xfs_dir2_block_addname(
xfs_da_args_t *args) /* directory op arguments */
{
xfs_dir2_data_hdr_t *hdr; /* block header */
xfs_dir2_leaf_entry_t *blp; /* block leaf entries */
struct xfs_buf *bp; /* buffer for block */
xfs_dir2_block_tail_t *btp; /* block tail */
int compact; /* need to compact leaf ents */
xfs_dir2_data_entry_t *dep; /* block data entry */
xfs_inode_t *dp; /* directory inode */
xfs_dir2_data_unused_t *dup; /* block unused entry */
int error; /* error return value */
xfs_dir2_data_unused_t *enddup=NULL; /* unused at end of data */
xfs_dahash_t hash; /* hash value of found entry */
int high; /* high index for binary srch */
int highstale; /* high stale index */
int lfloghigh=0; /* last final leaf to log */
int lfloglow=0; /* first final leaf to log */
int len; /* length of the new entry */
int low; /* low index for binary srch */
int lowstale; /* low stale index */
int mid=0; /* midpoint for binary srch */
xfs_mount_t *mp; /* filesystem mount point */
int needlog; /* need to log header */
int needscan; /* need to rescan freespace */
__be16 *tagp; /* pointer to tag value */
xfs_trans_t *tp; /* transaction structure */
trace_xfs_dir2_block_addname(args);
dp = args->dp;
tp = args->trans;
mp = dp->i_mount;
/* Read the (one and only) directory block into bp. */
error = xfs_dir3_block_read(tp, dp, &bp);
if (error)
return error;
len = xfs_dir2_data_entsize(args->namelen);
/*
* Set up pointers to parts of the block.
*/
hdr = bp->b_addr;
btp = xfs_dir2_block_tail_p(mp, hdr);
blp = xfs_dir2_block_leaf_p(btp);
/*
* Find out if we can reuse stale entries or whether we need extra
* space for entry and new leaf.
*/
xfs_dir2_block_need_space(hdr, btp, blp, &tagp, &dup,
&enddup, &compact, len);
/*
* Done everything we need for a space check now.
*/
if (args->op_flags & XFS_DA_OP_JUSTCHECK) {
xfs_trans_brelse(tp, bp);
if (!dup)
return XFS_ERROR(ENOSPC);
return 0;
}
/*
* If we don't have space for the new entry & leaf ...
*/
if (!dup) {
/* Don't have a space reservation: return no-space. */
if (args->total == 0)
return XFS_ERROR(ENOSPC);
/*
* Convert to the next larger format.
* Then add the new entry in that format.
*/
error = xfs_dir2_block_to_leaf(args, bp);
if (error)
return error;
return xfs_dir2_leaf_addname(args);
}
needlog = needscan = 0;
/*
* If need to compact the leaf entries, do it now.
*/
if (compact) {
xfs_dir2_block_compact(tp, bp, hdr, btp, blp, &needlog,
&lfloghigh, &lfloglow);
/* recalculate blp post-compaction */
blp = xfs_dir2_block_leaf_p(btp);
} else if (btp->stale) {
/*
* Set leaf logging boundaries to impossible state.
* For the no-stale case they're set explicitly.
*/
lfloglow = be32_to_cpu(btp->count);
lfloghigh = -1;
}
/*
* Find the slot that's first lower than our hash value, -1 if none.
*/
for (low = 0, high = be32_to_cpu(btp->count) - 1; low <= high; ) {
mid = (low + high) >> 1;
if ((hash = be32_to_cpu(blp[mid].hashval)) == args->hashval)
break;
if (hash < args->hashval)
low = mid + 1;
else
high = mid - 1;
}
while (mid >= 0 && be32_to_cpu(blp[mid].hashval) >= args->hashval) {
mid--;
}
/*
* No stale entries, will use enddup space to hold new leaf.
*/
if (!btp->stale) {
/*
* Mark the space needed for the new leaf entry, now in use.
*/
xfs_dir2_data_use_free(tp, bp, enddup,
(xfs_dir2_data_aoff_t)
((char *)enddup - (char *)hdr + be16_to_cpu(enddup->length) -
sizeof(*blp)),
(xfs_dir2_data_aoff_t)sizeof(*blp),
&needlog, &needscan);
/*
* Update the tail (entry count).
*/
be32_add_cpu(&btp->count, 1);
/*
* If we now need to rebuild the bestfree map, do so.
* This needs to happen before the next call to use_free.
*/
if (needscan) {
xfs_dir2_data_freescan(mp, hdr, &needlog);
needscan = 0;
}
/*
* Adjust pointer to the first leaf entry, we're about to move
* the table up one to open up space for the new leaf entry.
* Then adjust our index to match.
*/
blp--;
mid++;
if (mid)
memmove(blp, &blp[1], mid * sizeof(*blp));
lfloglow = 0;
lfloghigh = mid;
}
/*
* Use a stale leaf for our new entry.
*/
else {
for (lowstale = mid;
lowstale >= 0 &&
blp[lowstale].address !=
cpu_to_be32(XFS_DIR2_NULL_DATAPTR);
lowstale--)
continue;
for (highstale = mid + 1;
highstale < be32_to_cpu(btp->count) &&
blp[highstale].address !=
cpu_to_be32(XFS_DIR2_NULL_DATAPTR) &&
(lowstale < 0 || mid - lowstale > highstale - mid);
highstale++)
continue;
/*
* Move entries toward the low-numbered stale entry.
*/
if (lowstale >= 0 &&
(highstale == be32_to_cpu(btp->count) ||
mid - lowstale <= highstale - mid)) {
if (mid - lowstale)
memmove(&blp[lowstale], &blp[lowstale + 1],
(mid - lowstale) * sizeof(*blp));
lfloglow = MIN(lowstale, lfloglow);
lfloghigh = MAX(mid, lfloghigh);
}
/*
* Move entries toward the high-numbered stale entry.
*/
else {
ASSERT(highstale < be32_to_cpu(btp->count));
mid++;
if (highstale - mid)
memmove(&blp[mid + 1], &blp[mid],
(highstale - mid) * sizeof(*blp));
lfloglow = MIN(mid, lfloglow);
lfloghigh = MAX(highstale, lfloghigh);
}
be32_add_cpu(&btp->stale, -1);
}
/*
* Point to the new data entry.
*/
dep = (xfs_dir2_data_entry_t *)dup;
/*
* Fill in the leaf entry.
*/
blp[mid].hashval = cpu_to_be32(args->hashval);
blp[mid].address = cpu_to_be32(xfs_dir2_byte_to_dataptr(mp,
(char *)dep - (char *)hdr));
xfs_dir2_block_log_leaf(tp, bp, lfloglow, lfloghigh);
/*
* Mark space for the data entry used.
*/
xfs_dir2_data_use_free(tp, bp, dup,
(xfs_dir2_data_aoff_t)((char *)dup - (char *)hdr),
(xfs_dir2_data_aoff_t)len, &needlog, &needscan);
/*
* Create the new data entry.
*/
dep->inumber = cpu_to_be64(args->inumber);
dep->namelen = args->namelen;
memcpy(dep->name, args->name, args->namelen);
tagp = xfs_dir2_data_entry_tag_p(dep);
*tagp = cpu_to_be16((char *)dep - (char *)hdr);
/*
* Clean up the bestfree array and log the header, tail, and entry.
*/
if (needscan)
xfs_dir2_data_freescan(mp, hdr, &needlog);
if (needlog)
xfs_dir2_data_log_header(tp, bp);
xfs_dir2_block_log_tail(tp, bp);
xfs_dir2_data_log_entry(tp, bp, dep);
xfs_dir3_data_check(dp, bp);
return 0;
}
/*
* Readdir for block directories.
*/
int /* error */
xfs_dir2_block_getdents(
xfs_inode_t *dp, /* incore inode */
struct dir_context *ctx)
{
xfs_dir2_data_hdr_t *hdr; /* block header */
struct xfs_buf *bp; /* buffer for block */
xfs_dir2_block_tail_t *btp; /* block tail */
xfs_dir2_data_entry_t *dep; /* block data entry */
xfs_dir2_data_unused_t *dup; /* block unused entry */
char *endptr; /* end of the data entries */
int error; /* error return value */
xfs_mount_t *mp; /* filesystem mount point */
char *ptr; /* current data entry */
int wantoff; /* starting block offset */
xfs_off_t cook;
mp = dp->i_mount;
/*
* If the block number in the offset is out of range, we're done.
*/
if (xfs_dir2_dataptr_to_db(mp, ctx->pos) > mp->m_dirdatablk)
return 0;
error = xfs_dir3_block_read(NULL, dp, &bp);
if (error)
return error;
/*
* Extract the byte offset we start at from the seek pointer.
* We'll skip entries before this.
*/
wantoff = xfs_dir2_dataptr_to_off(mp, ctx->pos);
hdr = bp->b_addr;
xfs_dir3_data_check(dp, bp);
/*
* Set up values for the loop.
*/
btp = xfs_dir2_block_tail_p(mp, hdr);
ptr = (char *)xfs_dir3_data_entry_p(hdr);
endptr = (char *)xfs_dir2_block_leaf_p(btp);
/*
* Loop over the data portion of the block.
* Each object is a real entry (dep) or an unused one (dup).
*/
while (ptr < endptr) {
dup = (xfs_dir2_data_unused_t *)ptr;
/*
* Unused, skip it.
*/
if (be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG) {
ptr += be16_to_cpu(dup->length);
continue;
}
dep = (xfs_dir2_data_entry_t *)ptr;
/*
* Bump pointer for the next iteration.
*/
ptr += xfs_dir2_data_entsize(dep->namelen);
/*
* The entry is before the desired starting point, skip it.
*/
if ((char *)dep - (char *)hdr < wantoff)
continue;
cook = xfs_dir2_db_off_to_dataptr(mp, mp->m_dirdatablk,
(char *)dep - (char *)hdr);
ctx->pos = cook & 0x7fffffff;
/*
* If it didn't fit, set the final offset to here & return.
*/
if (!dir_emit(ctx, (char *)dep->name, dep->namelen,
be64_to_cpu(dep->inumber), DT_UNKNOWN)) {
xfs_trans_brelse(NULL, bp);
return 0;
}
}
/*
* Reached the end of the block.
* Set the offset to a non-existent block 1 and return.
*/
ctx->pos = xfs_dir2_db_off_to_dataptr(mp, mp->m_dirdatablk + 1, 0) &
0x7fffffff;
xfs_trans_brelse(NULL, bp);
return 0;
}
/*
* Log leaf entries from the block.
*/
static void
xfs_dir2_block_log_leaf(
xfs_trans_t *tp, /* transaction structure */
struct xfs_buf *bp, /* block buffer */
int first, /* index of first logged leaf */
int last) /* index of last logged leaf */
{
xfs_dir2_data_hdr_t *hdr = bp->b_addr;
xfs_dir2_leaf_entry_t *blp;
xfs_dir2_block_tail_t *btp;
btp = xfs_dir2_block_tail_p(tp->t_mountp, hdr);
blp = xfs_dir2_block_leaf_p(btp);
xfs_trans_log_buf(tp, bp, (uint)((char *)&blp[first] - (char *)hdr),
(uint)((char *)&blp[last + 1] - (char *)hdr - 1));
}
/*
* Log the block tail.
*/
static void
xfs_dir2_block_log_tail(
xfs_trans_t *tp, /* transaction structure */
struct xfs_buf *bp) /* block buffer */
{
xfs_dir2_data_hdr_t *hdr = bp->b_addr;
xfs_dir2_block_tail_t *btp;
btp = xfs_dir2_block_tail_p(tp->t_mountp, hdr);
xfs_trans_log_buf(tp, bp, (uint)((char *)btp - (char *)hdr),
(uint)((char *)(btp + 1) - (char *)hdr - 1));
}
/*
* Look up an entry in the block. This is the external routine,
* xfs_dir2_block_lookup_int does the real work.
*/
int /* error */
xfs_dir2_block_lookup(
xfs_da_args_t *args) /* dir lookup arguments */
{
xfs_dir2_data_hdr_t *hdr; /* block header */
xfs_dir2_leaf_entry_t *blp; /* block leaf entries */
struct xfs_buf *bp; /* block buffer */
xfs_dir2_block_tail_t *btp; /* block tail */
xfs_dir2_data_entry_t *dep; /* block data entry */
xfs_inode_t *dp; /* incore inode */
int ent; /* entry index */
int error; /* error return value */
xfs_mount_t *mp; /* filesystem mount point */
trace_xfs_dir2_block_lookup(args);
/*
* Get the buffer, look up the entry.
* If not found (ENOENT) then return, have no buffer.
*/
if ((error = xfs_dir2_block_lookup_int(args, &bp, &ent)))
return error;
dp = args->dp;
mp = dp->i_mount;
hdr = bp->b_addr;
xfs_dir3_data_check(dp, bp);
btp = xfs_dir2_block_tail_p(mp, hdr);
blp = xfs_dir2_block_leaf_p(btp);
/*
* Get the offset from the leaf entry, to point to the data.
*/
dep = (xfs_dir2_data_entry_t *)((char *)hdr +
xfs_dir2_dataptr_to_off(mp, be32_to_cpu(blp[ent].address)));
/*
* Fill in inode number, CI name if appropriate, release the block.
*/
args->inumber = be64_to_cpu(dep->inumber);
error = xfs_dir_cilookup_result(args, dep->name, dep->namelen);
xfs_trans_brelse(args->trans, bp);
return XFS_ERROR(error);
}
/*
* Internal block lookup routine.
*/
static int /* error */
xfs_dir2_block_lookup_int(
xfs_da_args_t *args, /* dir lookup arguments */
struct xfs_buf **bpp, /* returned block buffer */
int *entno) /* returned entry number */
{
xfs_dir2_dataptr_t addr; /* data entry address */
xfs_dir2_data_hdr_t *hdr; /* block header */
xfs_dir2_leaf_entry_t *blp; /* block leaf entries */
struct xfs_buf *bp; /* block buffer */
xfs_dir2_block_tail_t *btp; /* block tail */
xfs_dir2_data_entry_t *dep; /* block data entry */
xfs_inode_t *dp; /* incore inode */
int error; /* error return value */
xfs_dahash_t hash; /* found hash value */
int high; /* binary search high index */
int low; /* binary search low index */
int mid; /* binary search current idx */
xfs_mount_t *mp; /* filesystem mount point */
xfs_trans_t *tp; /* transaction pointer */
enum xfs_dacmp cmp; /* comparison result */
dp = args->dp;
tp = args->trans;
mp = dp->i_mount;
error = xfs_dir3_block_read(tp, dp, &bp);
if (error)
return error;
hdr = bp->b_addr;
xfs_dir3_data_check(dp, bp);
btp = xfs_dir2_block_tail_p(mp, hdr);
blp = xfs_dir2_block_leaf_p(btp);
/*
* Loop doing a binary search for our hash value.
* Find our entry, ENOENT if it's not there.
*/
for (low = 0, high = be32_to_cpu(btp->count) - 1; ; ) {
ASSERT(low <= high);
mid = (low + high) >> 1;
if ((hash = be32_to_cpu(blp[mid].hashval)) == args->hashval)
break;
if (hash < args->hashval)
low = mid + 1;
else
high = mid - 1;
if (low > high) {
ASSERT(args->op_flags & XFS_DA_OP_OKNOENT);
xfs_trans_brelse(tp, bp);
return XFS_ERROR(ENOENT);
}
}
/*
* Back up to the first one with the right hash value.
*/
while (mid > 0 && be32_to_cpu(blp[mid - 1].hashval) == args->hashval) {
mid--;
}
/*
* Now loop forward through all the entries with the
* right hash value looking for our name.
*/
do {
if ((addr = be32_to_cpu(blp[mid].address)) == XFS_DIR2_NULL_DATAPTR)
continue;
/*
* Get pointer to the entry from the leaf.
*/
dep = (xfs_dir2_data_entry_t *)
((char *)hdr + xfs_dir2_dataptr_to_off(mp, addr));
/*
* Compare name and if it's an exact match, return the index
* and buffer. If it's the first case-insensitive match, store
* the index and buffer and continue looking for an exact match.
*/
cmp = mp->m_dirnameops->compname(args, dep->name, dep->namelen);
if (cmp != XFS_CMP_DIFFERENT && cmp != args->cmpresult) {
args->cmpresult = cmp;
*bpp = bp;
*entno = mid;
if (cmp == XFS_CMP_EXACT)
return 0;
}
} while (++mid < be32_to_cpu(btp->count) &&
be32_to_cpu(blp[mid].hashval) == hash);
ASSERT(args->op_flags & XFS_DA_OP_OKNOENT);
/*
* Here, we can only be doing a lookup (not a rename or replace).
* If a case-insensitive match was found earlier, return success.
*/
if (args->cmpresult == XFS_CMP_CASE)
return 0;
/*
* No match, release the buffer and return ENOENT.
*/
xfs_trans_brelse(tp, bp);
return XFS_ERROR(ENOENT);
}
/*
* Remove an entry from a block format directory.
* If that makes the block small enough to fit in shortform, transform it.
*/
int /* error */
xfs_dir2_block_removename(
xfs_da_args_t *args) /* directory operation args */
{
xfs_dir2_data_hdr_t *hdr; /* block header */
xfs_dir2_leaf_entry_t *blp; /* block leaf pointer */
struct xfs_buf *bp; /* block buffer */
xfs_dir2_block_tail_t *btp; /* block tail */
xfs_dir2_data_entry_t *dep; /* block data entry */
xfs_inode_t *dp; /* incore inode */
int ent; /* block leaf entry index */
int error; /* error return value */
xfs_mount_t *mp; /* filesystem mount point */
int needlog; /* need to log block header */
int needscan; /* need to fixup bestfree */
xfs_dir2_sf_hdr_t sfh; /* shortform header */
int size; /* shortform size */
xfs_trans_t *tp; /* transaction pointer */
trace_xfs_dir2_block_removename(args);
/*
* Look up the entry in the block. Gets the buffer and entry index.
* It will always be there, the vnodeops level does a lookup first.
*/
if ((error = xfs_dir2_block_lookup_int(args, &bp, &ent))) {
return error;
}
dp = args->dp;
tp = args->trans;
mp = dp->i_mount;
hdr = bp->b_addr;
btp = xfs_dir2_block_tail_p(mp, hdr);
blp = xfs_dir2_block_leaf_p(btp);
/*
* Point to the data entry using the leaf entry.
*/
dep = (xfs_dir2_data_entry_t *)
((char *)hdr + xfs_dir2_dataptr_to_off(mp, be32_to_cpu(blp[ent].address)));
/*
* Mark the data entry's space free.
*/
needlog = needscan = 0;
xfs_dir2_data_make_free(tp, bp,
(xfs_dir2_data_aoff_t)((char *)dep - (char *)hdr),
xfs_dir2_data_entsize(dep->namelen), &needlog, &needscan);
/*
* Fix up the block tail.
*/
be32_add_cpu(&btp->stale, 1);
xfs_dir2_block_log_tail(tp, bp);
/*
* Remove the leaf entry by marking it stale.
*/
blp[ent].address = cpu_to_be32(XFS_DIR2_NULL_DATAPTR);
xfs_dir2_block_log_leaf(tp, bp, ent, ent);
/*
* Fix up bestfree, log the header if necessary.
*/
if (needscan)
xfs_dir2_data_freescan(mp, hdr, &needlog);
if (needlog)
xfs_dir2_data_log_header(tp, bp);
xfs_dir3_data_check(dp, bp);
/*
* See if the size as a shortform is good enough.
*/
size = xfs_dir2_block_sfsize(dp, hdr, &sfh);
if (size > XFS_IFORK_DSIZE(dp))
return 0;
/*
* If it works, do the conversion.
*/
return xfs_dir2_block_to_sf(args, bp, size, &sfh);
}
/*
* Replace an entry in a V2 block directory.
* Change the inode number to the new value.
*/
int /* error */
xfs_dir2_block_replace(
xfs_da_args_t *args) /* directory operation args */
{
xfs_dir2_data_hdr_t *hdr; /* block header */
xfs_dir2_leaf_entry_t *blp; /* block leaf entries */
struct xfs_buf *bp; /* block buffer */
xfs_dir2_block_tail_t *btp; /* block tail */
xfs_dir2_data_entry_t *dep; /* block data entry */
xfs_inode_t *dp; /* incore inode */
int ent; /* leaf entry index */
int error; /* error return value */
xfs_mount_t *mp; /* filesystem mount point */
trace_xfs_dir2_block_replace(args);
/*
* Lookup the entry in the directory. Get buffer and entry index.
* This will always succeed since the caller has already done a lookup.
*/
if ((error = xfs_dir2_block_lookup_int(args, &bp, &ent))) {
return error;
}
dp = args->dp;
mp = dp->i_mount;
hdr = bp->b_addr;
btp = xfs_dir2_block_tail_p(mp, hdr);
blp = xfs_dir2_block_leaf_p(btp);
/*
* Point to the data entry we need to change.
*/
dep = (xfs_dir2_data_entry_t *)
((char *)hdr + xfs_dir2_dataptr_to_off(mp, be32_to_cpu(blp[ent].address)));
ASSERT(be64_to_cpu(dep->inumber) != args->inumber);
/*
* Change the inode number to the new value.
*/
dep->inumber = cpu_to_be64(args->inumber);
xfs_dir2_data_log_entry(args->trans, bp, dep);
xfs_dir3_data_check(dp, bp);
return 0;
}
/*
* Qsort comparison routine for the block leaf entries.
*/
static int /* sort order */
xfs_dir2_block_sort(
const void *a, /* first leaf entry */
const void *b) /* second leaf entry */
{
const xfs_dir2_leaf_entry_t *la; /* first leaf entry */
const xfs_dir2_leaf_entry_t *lb; /* second leaf entry */
la = a;
lb = b;
return be32_to_cpu(la->hashval) < be32_to_cpu(lb->hashval) ? -1 :
(be32_to_cpu(la->hashval) > be32_to_cpu(lb->hashval) ? 1 : 0);
}
/*
* Convert a V2 leaf directory to a V2 block directory if possible.
*/
int /* error */
xfs_dir2_leaf_to_block(
xfs_da_args_t *args, /* operation arguments */
struct xfs_buf *lbp, /* leaf buffer */
struct xfs_buf *dbp) /* data buffer */