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Handle VMFS5's double indirect pointer for files > 256G #14

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7a25cd0
Handle VMFS5's double indirect pointer for files > 256G
May 22, 2015
92f00e6
Fix whitespace
Jun 5, 2015
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5 changes: 5 additions & 0 deletions libvmfs/vmfs_file.c
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Original file line number Diff line number Diff line change
Expand Up @@ -205,6 +205,11 @@ ssize_t vmfs_file_pread(vmfs_file_t *f,u_char *buf,size_t len,off_t pos)
break;
}

/* Pointer-Block, if we get here we failed to resolve pointer */
case VMFS_BLK_TYPE_PB:
fprintf(stderr, "VMFS: Pointer block at id 0x%8.8x\n", blk_id);
return(-EINVAL);

/* Inline in the inode */
case VMFS_BLK_TYPE_FD:
if (blk_id == f->inode->id) {
Expand Down
118 changes: 90 additions & 28 deletions libvmfs/vmfs_inode.c
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Original file line number Diff line number Diff line change
Expand Up @@ -311,36 +311,20 @@ int vmfs_inode_get_block(const vmfs_inode_t *inode,off_t pos,uint32_t *blk_id)

case VMFS_BLK_TYPE_PB:
{
DECL_ALIGNED_BUFFER_WOL(buf,fs->pbc->bmh.data_size);
uint32_t pb_blk_id;
uint32_t blk_per_pb;
u_int pb_index;
u_int sub_index;

blk_per_pb = fs->pbc->bmh.data_size / sizeof(uint32_t);
blk_index = pos / inode->blk_size;

pb_index = blk_index / blk_per_pb;
sub_index = blk_index % blk_per_pb;

if (pb_index >= VMFS_INODE_BLK_COUNT)
return(-EINVAL);

pb_blk_id = inode->blocks[pb_index];

if (!pb_blk_id)
break;

if (!vmfs_bitmap_get_item(fs->pbc,
VMFS_BLK_PB_ENTRY(pb_blk_id),
VMFS_BLK_PB_ITEM(pb_blk_id),
buf))
return(-EIO);

*blk_id = read_le32(buf,sub_index*sizeof(uint32_t));
int pointer_result = -EINVAL;
if (inode->blk_size == VMFS_DP_BLOCK_SZ &&
inode->size > VMFS_SP_MAX_SZ) {
pointer_result = vmfs_dp_get_block(fs, inode, pos, blk_id);
} else {
pointer_result = vmfs_sp_get_block(fs, inode, pos, blk_id);
}
if (pointer_result) {
fprintf(stderr, "Error in resolving pointer block: %d\n",
pointer_result);
return(pointer_result);
}
break;
}

case VMFS_BLK_TYPE_FD:
if (vmfs5_extension) {
*blk_id = inode->id;
Expand All @@ -354,6 +338,84 @@ int vmfs_inode_get_block(const vmfs_inode_t *inode,off_t pos,uint32_t *blk_id)
return(0);
}

/* read pointer to get block id */
int vmfs_sp_get_block(const vmfs_fs_t *fs, const vmfs_inode_t *inode, off_t pos,
uint32_t *blk_id) {
DECL_ALIGNED_BUFFER_WOL(buf,fs->pbc->bmh.data_size);
uint32_t pb_blk_id;
uint32_t blk_per_pb;
u_int pb_index;
u_int sub_index;
u_int blk_index;

blk_per_pb = fs->pbc->bmh.data_size / sizeof(uint32_t);
blk_index = pos / inode->blk_size;

pb_index = blk_index / blk_per_pb;
sub_index = blk_index % blk_per_pb;

if (pb_index >= VMFS_INODE_BLK_COUNT)
return(-EINVAL);

pb_blk_id = inode->blocks[pb_index];

if (!pb_blk_id) {
return(0);
}

if (!vmfs_bitmap_get_item(fs->pbc,
VMFS_BLK_PB_ENTRY(pb_blk_id),
VMFS_BLK_PB_ITEM(pb_blk_id),
buf)) {
return(-EIO);
}

*blk_id = read_le32(buf,sub_index*sizeof(uint32_t));

return(0);
}

/* read double pointer to get block */
int vmfs_dp_get_block(const vmfs_fs_t *fs, const vmfs_inode_t *inode, off_t pos,
uint32_t *blk_id) {
DECL_ALIGNED_BUFFER_WOL(buf,fs->pbc->bmh.data_size);
uint32_t pb_blk_id;
uint32_t di_blk_id;
uint32_t blk_per_pb;
u_int pb_index;
u_int sub_index;
u_int blk_index;
u_int di_pb_index;

blk_per_pb = fs->pbc->bmh.data_size / sizeof(uint32_t);
blk_index = pos / inode->blk_size;
pb_index = blk_index / (blk_per_pb * blk_per_pb);
di_pb_index = (blk_index / blk_per_pb) % blk_per_pb;
sub_index = blk_index % blk_per_pb;
pb_blk_id = inode->blocks[pb_index];

if (!pb_blk_id) {
return(0);
}
// read first pointer block
if (!vmfs_bitmap_get_item(fs->pbc,
VMFS_BLK_PB_ENTRY(pb_blk_id),
VMFS_BLK_PB_ITEM(pb_blk_id),
buf)) {
return(-EIO);
}
di_blk_id = read_le32(buf,di_pb_index*sizeof(uint32_t));
// read second pointer block
if (!vmfs_bitmap_get_item(fs->pbc,
VMFS_BLK_PB_ENTRY(di_blk_id),
VMFS_BLK_PB_ITEM(di_blk_id),
buf)) {
return(-EIO);
}
*blk_id = read_le32(buf, sub_index*sizeof(uint32_t));
return(0);
}

/* Aggregate a sub-block to a file block */
static int vmfs_inode_aggregate_fb(vmfs_inode_t *inode)
{
Expand Down
9 changes: 9 additions & 0 deletions libvmfs/vmfs_inode.h
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Original file line number Diff line number Diff line change
Expand Up @@ -26,6 +26,9 @@

#define VMFS_INODE_MAGIC 0x10c00001

#define VMFS_DP_BLOCK_SZ 0x100000
#define VMFS_SP_MAX_SZ 0x4000000000

struct vmfs_inode_raw {
struct vmfs_metadata_hdr_raw mdh;
uint32_t id;
Expand Down Expand Up @@ -136,6 +139,12 @@ int vmfs_inode_alloc(vmfs_fs_t *fs,u_int type,mode_t mode,vmfs_inode_t **inode);
*/
int vmfs_inode_get_block(const vmfs_inode_t *inode,off_t pos,uint32_t *blk_id);

/* Get block id from pointer block */
int vmfs_sp_get_block(const vmfs_fs_t *fs, const vmfs_inode_t *inode, off_t pos, uint32_t *blk_id);

/* Get block id from double indirect pointer block */
int vmfs_dp_get_block(const vmfs_fs_t *fs, const vmfs_inode_t *inode, off_t pos, uint32_t *blk_id);

/* Get a block for writing corresponding to the specified position */
int vmfs_inode_get_wrblock(vmfs_inode_t *inode,off_t pos,uint32_t *blk_id);

Expand Down