/*
* Pointer to an entry's tag word.
*/
static __be16 *
xfs_dir2_data_entry_tag_p(
struct xfs_dir2_data_entry *dep)
{
return (__be16 *)((char *)dep +
xfs_dir2_data_entsize(dep->namelen) - sizeof(__be16));
}
/*
* Check consistency of shortform directory, assert if bad.
*/
static void
xfs_dir2_sf_check(
xfs_da_args_t *args) /* operation arguments */
{
xfs_inode_t *dp; /* incore directory inode */
int i; /* entry number */
int i8count; /* number of big inode#s */
xfs_ino_t ino; /* entry inode number */
int offset; /* data offset */
xfs_dir2_sf_entry_t *sfep; /* shortform dir entry */
xfs_dir2_sf_hdr_t *sfp; /* shortform structure */
dp = args->dp;
sfp = (xfs_dir2_sf_hdr_t *)dp->i_df.if_u1.if_data;
offset = XFS_DIR2_DATA_FIRST_OFFSET;
ino = xfs_dir2_sf_get_parent_ino(sfp);
i8count = ino > XFS_DIR2_MAX_SHORT_INUM;
for (i = 0, sfep = xfs_dir2_sf_firstentry(sfp);
i < sfp->count;
i++, sfep = xfs_dir2_sf_nextentry(sfp, sfep)) {
ASSERT(xfs_dir2_sf_get_offset(sfep) >= offset);
ino = xfs_dir2_sfe_get_ino(sfp, sfep);
i8count += ino > XFS_DIR2_MAX_SHORT_INUM;
offset =
xfs_dir2_sf_get_offset(sfep) +
xfs_dir2_data_entsize(sfep->namelen);
}
ASSERT(i8count == sfp->i8count);
ASSERT(XFS_BIG_INUMS || i8count == 0);
ASSERT((char *)sfep - (char *)sfp == dp->i_d.di_size);
ASSERT(offset +
(sfp->count + 2) * (uint)sizeof(xfs_dir2_leaf_entry_t) +
(uint)sizeof(xfs_dir2_block_tail_t) <=
dp->i_mount->m_dirblksize);
}
/*ARGSUSED*/
static int /* pick result */
xfs_dir2_sf_addname_pick(
xfs_da_args_t *args, /* operation arguments */
int objchange, /* inode # size changes */
xfs_dir2_sf_entry_t **sfepp, /* out(1): new entry ptr */
xfs_dir2_data_aoff_t *offsetp) /* out(1): new offset */
{
xfs_inode_t *dp; /* incore directory inode */
int holefit; /* found hole it will fit in */
int i; /* entry number */
xfs_mount_t *mp; /* filesystem mount point */
xfs_dir2_data_aoff_t offset; /* data block offset */
xfs_dir2_sf_entry_t *sfep; /* shortform entry */
xfs_dir2_sf_hdr_t *sfp; /* shortform structure */
int size; /* entry's data size */
int used; /* data bytes used */
dp = args->dp;
mp = dp->i_mount;
sfp = (xfs_dir2_sf_hdr_t *)dp->i_df.if_u1.if_data;
size = xfs_dir2_data_entsize(args->namelen);
offset = XFS_DIR3_DATA_FIRST_OFFSET(mp);
sfep = xfs_dir2_sf_firstentry(sfp);
holefit = 0;
/*
* Loop over sf entries.
* Keep track of data offset and whether we've seen a place
* to insert the new entry.
*/
for (i = 0; i < sfp->count; i++) {
if (!holefit)
holefit = offset + size <= xfs_dir2_sf_get_offset(sfep);
offset = xfs_dir2_sf_get_offset(sfep) +
xfs_dir2_data_entsize(sfep->namelen);
sfep = xfs_dir2_sf_nextentry(sfp, sfep);
}
/*
* Calculate data bytes used excluding the new entry, if this
* was a data block (block form directory).
*/
used = offset +
(sfp->count + 3) * (uint)sizeof(xfs_dir2_leaf_entry_t) +
(uint)sizeof(xfs_dir2_block_tail_t);
/*
* If it won't fit in a block form then we can't insert it,
* we'll go back, convert to block, then try the insert and convert
* to leaf.
*/
if (used + (holefit ? 0 : size) > mp->m_dirblksize)
return 0;
/*
* If changing the inode number size, do it the hard way.
*/
#if XFS_BIG_INUMS
if (objchange) {
return 2;
}
#else
ASSERT(objchange == 0);
#endif
/*
* If it won't fit at the end then do it the hard way (use the hole).
*/
if (used + size > mp->m_dirblksize)
return 2;
/*
* Do it the easy way.
*/
*sfepp = sfep;
*offsetp = offset;
return 1;
}
/* ARGSUSED */
static void
xfs_dir2_sf_addname_hard(
xfs_da_args_t *args, /* operation arguments */
int objchange, /* changing inode number size */
int new_isize) /* new directory size */
{
int add_datasize; /* data size need for new ent */
char *buf; /* buffer for old */
xfs_inode_t *dp; /* incore directory inode */
int eof; /* reached end of old dir */
int nbytes; /* temp for byte copies */
xfs_dir2_data_aoff_t new_offset; /* next offset value */
xfs_dir2_data_aoff_t offset; /* current offset value */
int old_isize; /* previous di_size */
xfs_dir2_sf_entry_t *oldsfep; /* entry in original dir */
xfs_dir2_sf_hdr_t *oldsfp; /* original shortform dir */
xfs_dir2_sf_entry_t *sfep; /* entry in new dir */
xfs_dir2_sf_hdr_t *sfp; /* new shortform dir */
/*
* Copy the old directory to the stack buffer.
*/
dp = args->dp;
sfp = (xfs_dir2_sf_hdr_t *)dp->i_df.if_u1.if_data;
old_isize = (int)dp->i_d.di_size;
buf = kmem_alloc(old_isize, KM_SLEEP);
oldsfp = (xfs_dir2_sf_hdr_t *)buf;
memcpy(oldsfp, sfp, old_isize);
/*
* Loop over the old directory finding the place we're going
* to insert the new entry.
* If it's going to end up at the end then oldsfep will point there.
*/
for (offset = XFS_DIR3_DATA_FIRST_OFFSET(dp->i_mount),
oldsfep = xfs_dir2_sf_firstentry(oldsfp),
add_datasize = xfs_dir2_data_entsize(args->namelen),
eof = (char *)oldsfep == &buf[old_isize];
!eof;
offset = new_offset + xfs_dir2_data_entsize(oldsfep->namelen),
oldsfep = xfs_dir2_sf_nextentry(oldsfp, oldsfep),
eof = (char *)oldsfep == &buf[old_isize]) {
new_offset = xfs_dir2_sf_get_offset(oldsfep);
if (offset + add_datasize <= new_offset)
break;
}
/*
* Get rid of the old directory, then allocate space for
* the new one. We do this so xfs_idata_realloc won't copy
* the data.
*/
xfs_idata_realloc(dp, -old_isize, XFS_DATA_FORK);
xfs_idata_realloc(dp, new_isize, XFS_DATA_FORK);
/*
* Reset the pointer since the buffer was reallocated.
*/
sfp = (xfs_dir2_sf_hdr_t *)dp->i_df.if_u1.if_data;
/*
* Copy the first part of the directory, including the header.
*/
nbytes = (int)((char *)oldsfep - (char *)oldsfp);
memcpy(sfp, oldsfp, nbytes);
sfep = (xfs_dir2_sf_entry_t *)((char *)sfp + nbytes);
/*
* Fill in the new entry, and update the header counts.
*/
sfep->namelen = args->namelen;
xfs_dir2_sf_put_offset(sfep, offset);
memcpy(sfep->name, args->name, sfep->namelen);
xfs_dir2_sfe_put_ino(sfp, sfep, args->inumber);
sfp->count++;
#if XFS_BIG_INUMS
if (args->inumber > XFS_DIR2_MAX_SHORT_INUM && !objchange)
sfp->i8count++;
#endif
/*
* If there's more left to copy, do that.
*/
if (!eof) {
sfep = xfs_dir2_sf_nextentry(sfp, sfep);
memcpy(sfep, oldsfep, old_isize - nbytes);
}
kmem_free(buf);
dp->i_d.di_size = new_isize;
xfs_dir2_sf_check(args);
}
/*
* Convert a block format directory to shortform.
* Caller has already checked that it will fit, and built us a header.
*/
int /* error */
xfs_dir2_block_to_sf(
xfs_da_args_t *args, /* operation arguments */
struct xfs_buf *bp,
int size, /* shortform directory size */
xfs_dir2_sf_hdr_t *sfhp) /* shortform directory hdr */
{
xfs_dir2_data_hdr_t *hdr; /* block header */
xfs_dir2_block_tail_t *btp; /* block tail pointer */
xfs_dir2_data_entry_t *dep; /* data entry pointer */
xfs_inode_t *dp; /* incore directory inode */
xfs_dir2_data_unused_t *dup; /* unused data pointer */
char *endptr; /* end of data entries */
int error; /* error return value */
int logflags; /* inode logging flags */
xfs_mount_t *mp; /* filesystem mount point */
char *ptr; /* current data pointer */
xfs_dir2_sf_entry_t *sfep; /* shortform entry */
xfs_dir2_sf_hdr_t *sfp; /* shortform directory header */
trace_xfs_dir2_block_to_sf(args);
dp = args->dp;
mp = dp->i_mount;
/*
* Make a copy of the block data, so we can shrink the inode
* and add local data.
*/
hdr = kmem_alloc(mp->m_dirblksize, KM_SLEEP);
memcpy(hdr, bp->b_addr, mp->m_dirblksize);
logflags = XFS_ILOG_CORE;
if ((error = xfs_dir2_shrink_inode(args, mp->m_dirdatablk, bp))) {
ASSERT(error != ENOSPC);
goto out;
}
/*
* The buffer is now unconditionally gone, whether
* xfs_dir2_shrink_inode worked or not.
*
* Convert the inode to local format.
*/
dp->i_df.if_flags &= ~XFS_IFEXTENTS;
dp->i_df.if_flags |= XFS_IFINLINE;
dp->i_d.di_format = XFS_DINODE_FMT_LOCAL;
ASSERT(dp->i_df.if_bytes == 0);
xfs_idata_realloc(dp, size, XFS_DATA_FORK);
logflags |= XFS_ILOG_DDATA;
/*
* Copy the header into the newly allocate local space.
*/
sfp = (xfs_dir2_sf_hdr_t *)dp->i_df.if_u1.if_data;
memcpy(sfp, sfhp, xfs_dir2_sf_hdr_size(sfhp->i8count));
dp->i_d.di_size = size;
/*
* Set up to loop over the block's entries.
*/
btp = xfs_dir2_block_tail_p(mp, hdr);
ptr = (char *)xfs_dir3_data_entry_p(hdr);
endptr = (char *)xfs_dir2_block_leaf_p(btp);
sfep = xfs_dir2_sf_firstentry(sfp);
/*
* Loop over the active and unused entries.
* Stop when we reach the leaf/tail portion of the block.
*/
while (ptr < endptr) {
/*
* If it's unused, just skip over it.
*/
dup = (xfs_dir2_data_unused_t *)ptr;
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;
/*
* Skip .
*/
if (dep->namelen == 1 && dep->name[0] == '.')
ASSERT(be64_to_cpu(dep->inumber) == dp->i_ino);
/*
* Skip .., but make sure the inode number is right.
*/
else if (dep->namelen == 2 &&
dep->name[0] == '.' && dep->name[1] == '.')
ASSERT(be64_to_cpu(dep->inumber) ==
xfs_dir2_sf_get_parent_ino(sfp));
/*
* Normal entry, copy it into shortform.
*/
else {
sfep->namelen = dep->namelen;
xfs_dir2_sf_put_offset(sfep,
(xfs_dir2_data_aoff_t)
((char *)dep - (char *)hdr));
memcpy(sfep->name, dep->name, dep->namelen);
xfs_dir2_sfe_put_ino(sfp, sfep,
be64_to_cpu(dep->inumber));
sfep = xfs_dir2_sf_nextentry(sfp, sfep);
}
ptr += xfs_dir2_data_entsize(dep->namelen);
}
ASSERT((char *)sfep - (char *)sfp == size);
xfs_dir2_sf_check(args);
out:
xfs_trans_log_inode(args->trans, dp, logflags);
kmem_free(hdr);
return error;
}
/*
* Readdir for block directories.
*/
int /* error */
xfs_dir2_block_getdents(
xfs_inode_t *dp, /* incore inode */
void *dirent,
xfs_off_t *offset,
filldir_t filldir)
{
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, *offset) > mp->m_dirdatablk)
return 0;
error = xfs_dir2_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, *offset);
hdr = bp->b_addr;
xfs_dir2_data_check(dp, bp);
/*
* Set up values for the loop.
*/
btp = xfs_dir2_block_tail_p(mp, hdr);
ptr = (char *)(hdr + 1);
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);
/*
* If it didn't fit, set the final offset to here & return.
*/
if (filldir(dirent, (char *)dep->name, dep->namelen,
cook & 0x7fffffff, be64_to_cpu(dep->inumber),
DT_UNKNOWN)) {
*offset = cook & 0x7fffffff;
xfs_trans_brelse(NULL, bp);
return 0;
}
}
/*
* Reached the end of the block.
* Set the offset to a non-existent block 1 and return.
*/
*offset = xfs_dir2_db_off_to_dataptr(mp, mp->m_dirdatablk + 1, 0) &
0x7fffffff;
xfs_trans_brelse(NULL, bp);
return 0;
}
static void
xfs_dir2_sf_addname_hard(
xfs_da_args_t *args, /* */
int objchange, /* */
int new_isize) /* */
{
int add_datasize; /* */
char *buf; /* */
xfs_inode_t *dp; /* */
int eof; /* */
int nbytes; /* */
xfs_dir2_data_aoff_t new_offset; /* */
xfs_dir2_data_aoff_t offset; /* */
int old_isize; /* */
xfs_dir2_sf_entry_t *oldsfep; /* */
xfs_dir2_sf_hdr_t *oldsfp; /* */
xfs_dir2_sf_entry_t *sfep; /* */
xfs_dir2_sf_hdr_t *sfp; /* */
/*
*/
dp = args->dp;
sfp = (xfs_dir2_sf_hdr_t *)dp->i_df.if_u1.if_data;
old_isize = (int)dp->i_d.di_size;
buf = kmem_alloc(old_isize, KM_SLEEP);
oldsfp = (xfs_dir2_sf_hdr_t *)buf;
memcpy(oldsfp, sfp, old_isize);
/*
*/
for (offset = XFS_DIR2_DATA_FIRST_OFFSET,
oldsfep = xfs_dir2_sf_firstentry(oldsfp),
add_datasize = xfs_dir2_data_entsize(args->namelen),
eof = (char *)oldsfep == &buf[old_isize];
!eof;
offset = new_offset + xfs_dir2_data_entsize(oldsfep->namelen),
oldsfep = xfs_dir2_sf_nextentry(oldsfp, oldsfep),
eof = (char *)oldsfep == &buf[old_isize]) {
new_offset = xfs_dir2_sf_get_offset(oldsfep);
if (offset + add_datasize <= new_offset)
break;
}
/*
*/
xfs_idata_realloc(dp, -old_isize, XFS_DATA_FORK);
xfs_idata_realloc(dp, new_isize, XFS_DATA_FORK);
/*
*/
sfp = (xfs_dir2_sf_hdr_t *)dp->i_df.if_u1.if_data;
/*
*/
nbytes = (int)((char *)oldsfep - (char *)oldsfp);
memcpy(sfp, oldsfp, nbytes);
sfep = (xfs_dir2_sf_entry_t *)((char *)sfp + nbytes);
/*
*/
sfep->namelen = args->namelen;
xfs_dir2_sf_put_offset(sfep, offset);
memcpy(sfep->name, args->name, sfep->namelen);
xfs_dir2_sfe_put_ino(sfp, sfep, args->inumber);
sfp->count++;
#if XFS_BIG_INUMS
if (args->inumber > XFS_DIR2_MAX_SHORT_INUM && !objchange)
sfp->i8count++;
#endif
/*
*/
if (!eof) {
sfep = xfs_dir2_sf_nextentry(sfp, sfep);
memcpy(sfep, oldsfep, old_isize - nbytes);
}
kmem_free(buf);
dp->i_d.di_size = new_isize;
xfs_dir2_sf_check(args);
}
static int /* */
xfs_dir2_sf_addname_pick(
xfs_da_args_t *args, /* */
int objchange, /* */
xfs_dir2_sf_entry_t **sfepp, /* */
xfs_dir2_data_aoff_t *offsetp) /* */
{
xfs_inode_t *dp; /* */
int holefit; /* */
int i; /* */
xfs_mount_t *mp; /* */
xfs_dir2_data_aoff_t offset; /* */
xfs_dir2_sf_entry_t *sfep; /* */
xfs_dir2_sf_hdr_t *sfp; /* */
int size; /* */
int used; /* */
dp = args->dp;
mp = dp->i_mount;
sfp = (xfs_dir2_sf_hdr_t *)dp->i_df.if_u1.if_data;
size = xfs_dir2_data_entsize(args->namelen);
offset = XFS_DIR2_DATA_FIRST_OFFSET;
sfep = xfs_dir2_sf_firstentry(sfp);
holefit = 0;
/*
*/
for (i = 0; i < sfp->count; i++) {
if (!holefit)
holefit = offset + size <= xfs_dir2_sf_get_offset(sfep);
offset = xfs_dir2_sf_get_offset(sfep) +
xfs_dir2_data_entsize(sfep->namelen);
sfep = xfs_dir2_sf_nextentry(sfp, sfep);
}
/*
*/
used = offset +
(sfp->count + 3) * (uint)sizeof(xfs_dir2_leaf_entry_t) +
(uint)sizeof(xfs_dir2_block_tail_t);
/*
*/
if (used + (holefit ? 0 : size) > mp->m_dirblksize)
return 0;
/*
*/
#if XFS_BIG_INUMS
if (objchange) {
return 2;
}
#else
ASSERT(objchange == 0);
#endif
/*
*/
if (used + size > mp->m_dirblksize)
return 2;
/*
*/
*sfepp = sfep;
*offsetp = offset;
return 1;
}
int /* */
xfs_dir2_block_to_sf(
xfs_da_args_t *args, /* */
xfs_dabuf_t *bp, /* */
int size, /* */
xfs_dir2_sf_hdr_t *sfhp) /* */
{
xfs_dir2_data_hdr_t *hdr; /* */
xfs_dir2_block_tail_t *btp; /* */
xfs_dir2_data_entry_t *dep; /* */
xfs_inode_t *dp; /* */
xfs_dir2_data_unused_t *dup; /* */
char *endptr; /* */
int error; /* */
int logflags; /* */
xfs_mount_t *mp; /* */
char *ptr; /* */
xfs_dir2_sf_entry_t *sfep; /* */
xfs_dir2_sf_hdr_t *sfp; /* */
trace_xfs_dir2_block_to_sf(args);
dp = args->dp;
mp = dp->i_mount;
/*
*/
hdr = kmem_alloc(mp->m_dirblksize, KM_SLEEP);
memcpy(hdr, bp->data, mp->m_dirblksize);
logflags = XFS_ILOG_CORE;
if ((error = xfs_dir2_shrink_inode(args, mp->m_dirdatablk, bp))) {
ASSERT(error != ENOSPC);
goto out;
}
/*
*/
dp->i_df.if_flags &= ~XFS_IFEXTENTS;
dp->i_df.if_flags |= XFS_IFINLINE;
dp->i_d.di_format = XFS_DINODE_FMT_LOCAL;
ASSERT(dp->i_df.if_bytes == 0);
xfs_idata_realloc(dp, size, XFS_DATA_FORK);
logflags |= XFS_ILOG_DDATA;
/*
*/
sfp = (xfs_dir2_sf_hdr_t *)dp->i_df.if_u1.if_data;
memcpy(sfp, sfhp, xfs_dir2_sf_hdr_size(sfhp->i8count));
dp->i_d.di_size = size;
/*
*/
btp = xfs_dir2_block_tail_p(mp, hdr);
ptr = (char *)(hdr + 1);
endptr = (char *)xfs_dir2_block_leaf_p(btp);
sfep = xfs_dir2_sf_firstentry(sfp);
/*
*/
while (ptr < endptr) {
/*
*/
dup = (xfs_dir2_data_unused_t *)ptr;
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;
/*
*/
if (dep->namelen == 1 && dep->name[0] == '.')
ASSERT(be64_to_cpu(dep->inumber) == dp->i_ino);
/*
*/
else if (dep->namelen == 2 &&
dep->name[0] == '.' && dep->name[1] == '.')
ASSERT(be64_to_cpu(dep->inumber) ==
xfs_dir2_sf_get_parent_ino(sfp));
/*
*/
else {
sfep->namelen = dep->namelen;
xfs_dir2_sf_put_offset(sfep,
(xfs_dir2_data_aoff_t)
((char *)dep - (char *)hdr));
memcpy(sfep->name, dep->name, dep->namelen);
xfs_dir2_sfe_put_ino(sfp, sfep,
be64_to_cpu(dep->inumber));
sfep = xfs_dir2_sf_nextentry(sfp, sfep);
}
ptr += xfs_dir2_data_entsize(dep->namelen);
}
ASSERT((char *)sfep - (char *)sfp == size);
xfs_dir2_sf_check(args);
out:
xfs_trans_log_inode(args->trans, dp, logflags);
kmem_free(hdr);
return error;
}
/*
* Getdents (readdir) for leaf and node directories.
* This reads the data blocks only, so is the same for both forms.
*/
int /* error */
xfs_dir2_leaf_getdents(
xfs_inode_t *dp, /* incore directory inode */
void *dirent,
size_t bufsize,
xfs_off_t *offset,
filldir_t filldir)
{
xfs_dabuf_t *bp; /* data block buffer */
int byteoff; /* offset in current block */
xfs_dir2_db_t curdb; /* db for current block */
xfs_dir2_off_t curoff; /* current overall offset */
xfs_dir2_data_t *data; /* data block structure */
xfs_dir2_data_entry_t *dep; /* data entry */
xfs_dir2_data_unused_t *dup; /* unused entry */
int error = 0; /* error return value */
int i; /* temporary loop index */
int j; /* temporary loop index */
int length; /* temporary length value */
xfs_bmbt_irec_t *map; /* map vector for blocks */
xfs_extlen_t map_blocks; /* number of fsbs in map */
xfs_dablk_t map_off; /* last mapped file offset */
int map_size; /* total entries in *map */
int map_valid; /* valid entries in *map */
xfs_mount_t *mp; /* filesystem mount point */
xfs_dir2_off_t newoff; /* new curoff after new blk */
int nmap; /* mappings to ask xfs_bmapi */
char *ptr = NULL; /* pointer to current data */
int ra_current; /* number of read-ahead blks */
int ra_index; /* *map index for read-ahead */
int ra_offset; /* map entry offset for ra */
int ra_want; /* readahead count wanted */
/*
* If the offset is at or past the largest allowed value,
* give up right away.
*/
if (*offset >= XFS_DIR2_MAX_DATAPTR)
return 0;
mp = dp->i_mount;
/*
* Set up to bmap a number of blocks based on the caller's
* buffer size, the directory block size, and the filesystem
* block size.
*/
map_size = howmany(bufsize + mp->m_dirblksize, mp->m_sb.sb_blocksize);
map = kmem_alloc(map_size * sizeof(*map), KM_SLEEP);
map_valid = ra_index = ra_offset = ra_current = map_blocks = 0;
bp = NULL;
/*
* Inside the loop we keep the main offset value as a byte offset
* in the directory file.
*/
curoff = xfs_dir2_dataptr_to_byte(mp, *offset);
/*
* Force this conversion through db so we truncate the offset
* down to get the start of the data block.
*/
map_off = xfs_dir2_db_to_da(mp, xfs_dir2_byte_to_db(mp, curoff));
/*
* Loop over directory entries until we reach the end offset.
* Get more blocks and readahead as necessary.
*/
while (curoff < XFS_DIR2_LEAF_OFFSET) {
/*
* If we have no buffer, or we're off the end of the
* current buffer, need to get another one.
*/
if (!bp || ptr >= (char *)bp->data + mp->m_dirblksize) {
/*
* If we have a buffer, we need to release it and
* take it out of the mapping.
*/
if (bp) {
xfs_da_brelse(NULL, bp);
bp = NULL;
map_blocks -= mp->m_dirblkfsbs;
/*
* Loop to get rid of the extents for the
* directory block.
*/
for (i = mp->m_dirblkfsbs; i > 0; ) {
j = MIN((int)map->br_blockcount, i);
map->br_blockcount -= j;
map->br_startblock += j;
map->br_startoff += j;
/*
* If mapping is done, pitch it from
* the table.
*/
if (!map->br_blockcount && --map_valid)
memmove(&map[0], &map[1],
sizeof(map[0]) *
map_valid);
i -= j;
}
}
/*
* Recalculate the readahead blocks wanted.
*/
ra_want = howmany(bufsize + mp->m_dirblksize,
mp->m_sb.sb_blocksize) - 1;
ASSERT(ra_want >= 0);
/*
* If we don't have as many as we want, and we haven't
* run out of data blocks, get some more mappings.
*/
if (1 + ra_want > map_blocks &&
map_off <
xfs_dir2_byte_to_da(mp, XFS_DIR2_LEAF_OFFSET)) {
/*
* Get more bmaps, fill in after the ones
* we already have in the table.
*/
nmap = map_size - map_valid;
error = xfs_bmapi(NULL, dp,
map_off,
xfs_dir2_byte_to_da(mp,
XFS_DIR2_LEAF_OFFSET) - map_off,
XFS_BMAPI_METADATA, NULL, 0,
&map[map_valid], &nmap, NULL, NULL);
/*
* Don't know if we should ignore this or
* try to return an error.
* The trouble with returning errors
* is that readdir will just stop without
* actually passing the error through.
*/
if (error)
break; /* XXX */
/*
* If we got all the mappings we asked for,
* set the final map offset based on the
* last bmap value received.
* Otherwise, we've reached the end.
*/
if (nmap == map_size - map_valid)
map_off =
map[map_valid + nmap - 1].br_startoff +
map[map_valid + nmap - 1].br_blockcount;
else
map_off =
xfs_dir2_byte_to_da(mp,
XFS_DIR2_LEAF_OFFSET);
/*
* Look for holes in the mapping, and
* eliminate them. Count up the valid blocks.
*/
for (i = map_valid; i < map_valid + nmap; ) {
if (map[i].br_startblock ==
HOLESTARTBLOCK) {
nmap--;
length = map_valid + nmap - i;
if (length)
memmove(&map[i],
&map[i + 1],
sizeof(map[i]) *
length);
} else {
map_blocks +=
map[i].br_blockcount;
i++;
}
}
map_valid += nmap;
}
/*
* No valid mappings, so no more data blocks.
*/
if (!map_valid) {
curoff = xfs_dir2_da_to_byte(mp, map_off);
break;
}
/*
* Read the directory block starting at the first
* mapping.
*/
curdb = xfs_dir2_da_to_db(mp, map->br_startoff);
error = xfs_da_read_buf(NULL, dp, map->br_startoff,
map->br_blockcount >= mp->m_dirblkfsbs ?
XFS_FSB_TO_DADDR(mp, map->br_startblock) :
-1,
&bp, XFS_DATA_FORK);
/*
* Should just skip over the data block instead
* of giving up.
*/
if (error)
break; /* XXX */
/*
* Adjust the current amount of read-ahead: we just
* read a block that was previously ra.
*/
if (ra_current)
ra_current -= mp->m_dirblkfsbs;
/*
* Do we need more readahead?
*/
for (ra_index = ra_offset = i = 0;
ra_want > ra_current && i < map_blocks;
i += mp->m_dirblkfsbs) {
ASSERT(ra_index < map_valid);
/*
* Read-ahead a contiguous directory block.
*/
if (i > ra_current &&
map[ra_index].br_blockcount >=
mp->m_dirblkfsbs) {
//TODO: make sure this is right, should readahead be
//replaced by readbuf?
//xfs_buf_readahead(mp->m_ddev_targp,
// XFS_FSB_TO_DADDR(mp,
// map[ra_index].br_startblock +
// ra_offset),
// (int)BTOBB(mp->m_dirblksize));
//TODO: figure out flags, flags =0
//libxfs_readbuf(mp->m_dev,
// XFS_FSB_TO_DADDR(mp,
// map[ra_index].br_startblock +
// ra_offset),
// (int)BTOBB(mp->m_dirblksize), 0);
ra_current = i;
}
/*
* Read-ahead a non-contiguous directory block.
* This doesn't use our mapping, but this
* is a very rare case.
*/
else if (i > ra_current) {
(void)xfs_da_reada_buf(NULL, dp,
map[ra_index].br_startoff +
ra_offset, XFS_DATA_FORK);
ra_current = i;
}
/*
* Advance offset through the mapping table.
*/
for (j = 0; j < mp->m_dirblkfsbs; j++) {
/*
* The rest of this extent but not
* more than a dir block.
*/
length = MIN(mp->m_dirblkfsbs,
(int)(map[ra_index].br_blockcount -
ra_offset));
j += length;
ra_offset += length;
/*
* Advance to the next mapping if
* this one is used up.
*/
if (ra_offset ==
map[ra_index].br_blockcount) {
ra_offset = 0;
ra_index++;
}
}
}
/*
* Having done a read, we need to set a new offset.
*/
newoff = xfs_dir2_db_off_to_byte(mp, curdb, 0);
/*
* Start of the current block.
*/
if (curoff < newoff)
curoff = newoff;
/*
* Make sure we're in the right block.
*/
else if (curoff > newoff)
ASSERT(xfs_dir2_byte_to_db(mp, curoff) ==
curdb);
data = bp->data;
xfs_dir2_data_check(dp, bp);
/*
* Find our position in the block.
*/
ptr = (char *)&data->u;
byteoff = xfs_dir2_byte_to_off(mp, curoff);
/*
* Skip past the header.
*/
if (byteoff == 0)
curoff += (uint)sizeof(data->hdr);
/*
* Skip past entries until we reach our offset.
*/
else {
while ((char *)ptr - (char *)data < byteoff) {
dup = (xfs_dir2_data_unused_t *)ptr;
if (be16_to_cpu(dup->freetag)
== XFS_DIR2_DATA_FREE_TAG) {
length = be16_to_cpu(dup->length);
ptr += length;
continue;
}
dep = (xfs_dir2_data_entry_t *)ptr;
length =
xfs_dir2_data_entsize(dep->namelen);
ptr += length;
}
/*
* Now set our real offset.
*/
curoff =
xfs_dir2_db_off_to_byte(mp,
xfs_dir2_byte_to_db(mp, curoff),
(char *)ptr - (char *)data);
if (ptr >= (char *)data + mp->m_dirblksize) {
continue;
}
}
}
/*
* We have a pointer to an entry.
* Is it a live one?
*/
dup = (xfs_dir2_data_unused_t *)ptr;
/*
* No, it's unused, skip over it.
*/
if (be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG) {
length = be16_to_cpu(dup->length);
ptr += length;
curoff += length;
continue;
}
dep = (xfs_dir2_data_entry_t *)ptr;
length = xfs_dir2_data_entsize(dep->namelen);
if (filldir(dirent, (char *)dep->name, dep->namelen,
xfs_dir2_byte_to_dataptr(mp, curoff) & 0x7fffffff,
be64_to_cpu(dep->inumber), DT_UNKNOWN))
break;
/*
* Advance to next entry in the block.
*/
ptr += length;
curoff += length;
/* bufsize may have just been a guess; don't go negative */
bufsize = bufsize > length ? bufsize - length : 0;
}
/*
* All done. Set output offset value to current offset.
*/
if (curoff > xfs_dir2_dataptr_to_byte(mp, XFS_DIR2_MAX_DATAPTR))
*offset = XFS_DIR2_MAX_DATAPTR & 0x7fffffff;
else
*offset = xfs_dir2_byte_to_dataptr(mp, curoff) & 0x7fffffff;
kmem_free(map);
if (bp)
xfs_da_brelse(NULL, bp);
return error;
}
/*
* 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_block_t *block; /* block structure */
xfs_dir2_leaf_entry_t *blp; /* block leaf pointer */
xfs_dabuf_t *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;
block = bp->data;
btp = xfs_dir2_block_tail_p(mp, block);
blp = xfs_dir2_block_leaf_p(btp);
/*
* Point to the data entry using the leaf entry.
*/
dep = (xfs_dir2_data_entry_t *)
((char *)block + 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 *)block),
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, (xfs_dir2_data_t *)block, &needlog);
if (needlog)
xfs_dir2_data_log_header(tp, bp);
xfs_dir2_data_check(dp, bp);
/*
* See if the size as a shortform is good enough.
*/
if ((size = xfs_dir2_block_sfsize(dp, block, &sfh)) >
XFS_IFORK_DSIZE(dp)) {
xfs_da_buf_done(bp);
return 0;
}
/*
* If it works, do the conversion.
*/
return xfs_dir2_block_to_sf(args, bp, size, &sfh);
}
/*
* Add an entry to a block directory.
*/
int /* error */
xfs_dir2_block_addname(
xfs_da_args_t *args) /* directory op arguments */
{
xfs_dir2_data_free_t *bf; /* bestfree table in block */
xfs_dir2_block_t *block; /* directory block structure */
xfs_dir2_leaf_entry_t *blp; /* block leaf entries */
xfs_dabuf_t *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 dabuf bp.
*/
if ((error =
xfs_da_read_buf(tp, dp, mp->m_dirdatablk, -1, &bp, XFS_DATA_FORK))) {
return error;
}
ASSERT(bp != NULL);
block = bp->data;
/*
* Check the magic number, corrupted if wrong.
*/
if (unlikely(be32_to_cpu(block->hdr.magic) != XFS_DIR2_BLOCK_MAGIC)) {
XFS_CORRUPTION_ERROR("xfs_dir2_block_addname",
XFS_ERRLEVEL_LOW, mp, block);
xfs_da_brelse(tp, bp);
return XFS_ERROR(EFSCORRUPTED);
}
len = xfs_dir2_data_entsize(args->namelen);
/*
* Set up pointers to parts of the block.
*/
bf = block->hdr.bestfree;
btp = xfs_dir2_block_tail_p(mp, block);
blp = xfs_dir2_block_leaf_p(btp);
/*
* No stale entries? Need space for entry and new leaf.
*/
if (!btp->stale) {
/*
* 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 *)block + 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)
dup = enddup = NULL;
/*
* Check out the biggest freespace and see if it's the same one.
*/
else {
dup = (xfs_dir2_data_unused_t *)
((char *)block + be16_to_cpu(bf[0].offset));
if (dup == enddup) {
/*
* It is the biggest freespace, is it too small
* to hold the new leaf too?
*/
if (be16_to_cpu(dup->length) < len + (uint)sizeof(*blp)) {
/*
* Yes, we use the second-largest
* entry instead if it works.
*/
if (be16_to_cpu(bf[1].length) >= len)
dup = (xfs_dir2_data_unused_t *)
((char *)block +
be16_to_cpu(bf[1].offset));
else
dup = NULL;
}
} else {
/*
* Not the same free entry,
* just check its length.
*/
if (be16_to_cpu(dup->length) < len) {
dup = NULL;
}
}
}
compact = 0;
}
/*
* If there are stale entries we'll use one for the leaf.
* Is the biggest entry enough to avoid compaction?
*/
else if (be16_to_cpu(bf[0].length) >= len) {
dup = (xfs_dir2_data_unused_t *)
((char *)block + be16_to_cpu(bf[0].offset));
compact = 0;
}
/*
* Will need to compact to make this work.
*/
else {
/*
* Tag just before the first leaf entry.
*/
tagp = (__be16 *)blp - 1;
/*
* Data object just before the first leaf entry.
*/
dup = (xfs_dir2_data_unused_t *)((char *)block + 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;
compact = 1;
}
/*
* If this isn't a real add, we're done with the buffer.
*/
if (args->op_flags & XFS_DA_OP_JUSTCHECK)
xfs_da_brelse(tp, bp);
/*
* If we don't have space for the new entry & leaf ...
*/
if (!dup) {
/*
* Not trying to actually do anything, or don't have
* a space reservation: return no-space.
*/
if ((args->op_flags & XFS_DA_OP_JUSTCHECK) || 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);
xfs_da_buf_done(bp);
if (error)
return error;
return xfs_dir2_leaf_addname(args);
}
/*
* Just checking, and it would work, so say so.
*/
if (args->op_flags & XFS_DA_OP_JUSTCHECK)
return 0;
needlog = needscan = 0;
/*
* If need to compact the leaf entries, do it now.
* Leave the highest-numbered stale entry stale.
* XXX should be the one closest to mid but mid is not yet computed.
*/
if (compact) {
int fromidx; /* source leaf index */
int toidx; /* target leaf index */
for (fromidx = toidx = be32_to_cpu(btp->count) - 1,
highstale = lfloghigh = -1;
fromidx >= 0;
fromidx--) {
if (be32_to_cpu(blp[fromidx].address) == 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 *)block),
(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(mp, (xfs_dir2_data_t *)block, &needlog);
needscan = 0;
}
}
/*
* Set leaf logging boundaries to impossible state.
* For the no-stale case they're set explicitly.
*/
else if (btp->stale) {
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 *)block + 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, (xfs_dir2_data_t *)block,
&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 &&
be32_to_cpu(blp[lowstale].address) != XFS_DIR2_NULL_DATAPTR;
lowstale--)
continue;
for (highstale = mid + 1;
highstale < be32_to_cpu(btp->count) &&
be32_to_cpu(blp[highstale].address) != 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 *)block));
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 *)block),
(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 *)block);
/*
* Clean up the bestfree array and log the header, tail, and entry.
*/
if (needscan)
xfs_dir2_data_freescan(mp, (xfs_dir2_data_t *)block, &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_dir2_data_check(dp, bp);
xfs_da_buf_done(bp);
return 0;
}
/*
* Readdir for block directories.
*/
int /* error */
xfs_dir2_block_getdents(
xfs_inode_t *dp, /* incore inode */
void *dirent,
xfs_off_t *offset,
filldir_t filldir)
{
xfs_dir2_block_t *block; /* directory block structure */
xfs_dabuf_t *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_ino_t ino;
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, *offset) > mp->m_dirdatablk) {
return 0;
}
/*
* Can't read the block, give up, else get dabuf in bp.
*/
error = xfs_da_read_buf(NULL, dp, mp->m_dirdatablk, -1,
&bp, XFS_DATA_FORK);
if (error)
return error;
ASSERT(bp != NULL);
/*
* Extract the byte offset we start at from the seek pointer.
* We'll skip entries before this.
*/
wantoff = xfs_dir2_dataptr_to_off(mp, *offset);
block = bp->data;
xfs_dir2_data_check(dp, bp);
/*
* Set up values for the loop.
*/
btp = xfs_dir2_block_tail_p(mp, block);
ptr = (char *)block->u;
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 *)block < wantoff)
continue;
cook = xfs_dir2_db_off_to_dataptr(mp, mp->m_dirdatablk,
(char *)dep - (char *)block);
ino = be64_to_cpu(dep->inumber);
#if XFS_BIG_INUMS
ino += mp->m_inoadd;
#endif
/*
* If it didn't fit, set the final offset to here & return.
*/
if (filldir(dirent, dep->name, dep->namelen, cook,
ino, DT_UNKNOWN)) {
*offset = cook;
xfs_da_brelse(NULL, bp);
return 0;
}
}
/*
* Reached the end of the block.
* Set the offset to a non-existent block 1 and return.
*/
*offset = xfs_dir2_db_off_to_dataptr(mp, mp->m_dirdatablk + 1, 0);
xfs_da_brelse(NULL, bp);
return 0;
}
