WSL2-Linux-Kernel/fs/orangefs/dir.c

397 строки
10 KiB
C

/*
* (C) 2001 Clemson University and The University of Chicago
*
* See COPYING in top-level directory.
*/
#include "protocol.h"
#include "orangefs-kernel.h"
#include "orangefs-bufmap.h"
/*
* decode routine used by kmod to deal with the blob sent from
* userspace for readdirs. The blob contains zero or more of these
* sub-blobs:
* __u32 - represents length of the character string that follows.
* string - between 1 and ORANGEFS_NAME_MAX bytes long.
* padding - (if needed) to cause the __u32 plus the string to be
* eight byte aligned.
* khandle - sizeof(khandle) bytes.
*/
static long decode_dirents(char *ptr, size_t size,
struct orangefs_readdir_response_s *readdir)
{
int i;
struct orangefs_readdir_response_s *rd =
(struct orangefs_readdir_response_s *) ptr;
char *buf = ptr;
int khandle_size = sizeof(struct orangefs_khandle);
size_t offset = offsetof(struct orangefs_readdir_response_s,
dirent_array);
/* 8 reflects eight byte alignment */
int smallest_blob = khandle_size + 8;
__u32 len;
int aligned_len;
int sizeof_u32 = sizeof(__u32);
long ret;
gossip_debug(GOSSIP_DIR_DEBUG, "%s: size:%zu:\n", __func__, size);
/* size is = offset on empty dirs, > offset on non-empty dirs... */
if (size < offset) {
gossip_err("%s: size:%zu: offset:%zu:\n",
__func__,
size,
offset);
ret = -EINVAL;
goto out;
}
if ((size == offset) && (readdir->orangefs_dirent_outcount != 0)) {
gossip_err("%s: size:%zu: dirent_outcount:%d:\n",
__func__,
size,
readdir->orangefs_dirent_outcount);
ret = -EINVAL;
goto out;
}
readdir->token = rd->token;
readdir->orangefs_dirent_outcount = rd->orangefs_dirent_outcount;
readdir->dirent_array = kcalloc(readdir->orangefs_dirent_outcount,
sizeof(*readdir->dirent_array),
GFP_KERNEL);
if (readdir->dirent_array == NULL) {
gossip_err("%s: kcalloc failed.\n", __func__);
ret = -ENOMEM;
goto out;
}
buf += offset;
size -= offset;
for (i = 0; i < readdir->orangefs_dirent_outcount; i++) {
if (size < smallest_blob) {
gossip_err("%s: size:%zu: smallest_blob:%d:\n",
__func__,
size,
smallest_blob);
ret = -EINVAL;
goto free;
}
len = *(__u32 *)buf;
if ((len < 1) || (len > ORANGEFS_NAME_MAX)) {
gossip_err("%s: len:%d:\n", __func__, len);
ret = -EINVAL;
goto free;
}
gossip_debug(GOSSIP_DIR_DEBUG,
"%s: size:%zu: len:%d:\n",
__func__,
size,
len);
readdir->dirent_array[i].d_name = buf + sizeof_u32;
readdir->dirent_array[i].d_length = len;
/*
* Calculate "aligned" length of this string and its
* associated __u32 descriptor.
*/
aligned_len = ((sizeof_u32 + len + 1) + 7) & ~7;
gossip_debug(GOSSIP_DIR_DEBUG,
"%s: aligned_len:%d:\n",
__func__,
aligned_len);
/*
* The end of the blob should coincide with the end
* of the last sub-blob.
*/
if (size < aligned_len + khandle_size) {
gossip_err("%s: ran off the end of the blob.\n",
__func__);
ret = -EINVAL;
goto free;
}
size -= aligned_len + khandle_size;
buf += aligned_len;
readdir->dirent_array[i].khandle =
*(struct orangefs_khandle *) buf;
buf += khandle_size;
}
ret = buf - ptr;
gossip_debug(GOSSIP_DIR_DEBUG, "%s: returning:%ld:\n", __func__, ret);
goto out;
free:
kfree(readdir->dirent_array);
readdir->dirent_array = NULL;
out:
return ret;
}
/*
* Read directory entries from an instance of an open directory.
*/
static int orangefs_readdir(struct file *file, struct dir_context *ctx)
{
int ret = 0;
int buffer_index;
/*
* ptoken supports Orangefs' distributed directory logic, added
* in 2.9.2.
*/
__u64 *ptoken = file->private_data;
__u64 pos = 0;
ino_t ino = 0;
struct dentry *dentry = file->f_path.dentry;
struct orangefs_kernel_op_s *new_op = NULL;
struct orangefs_inode_s *orangefs_inode = ORANGEFS_I(dentry->d_inode);
struct orangefs_readdir_response_s readdir_response;
void *dents_buf;
int i = 0;
int len = 0;
ino_t current_ino = 0;
char *current_entry = NULL;
long bytes_decoded;
gossip_debug(GOSSIP_DIR_DEBUG,
"%s: ctx->pos:%lld, ptoken = %llu\n",
__func__,
lld(ctx->pos),
llu(*ptoken));
pos = (__u64) ctx->pos;
/* are we done? */
if (pos == ORANGEFS_READDIR_END) {
gossip_debug(GOSSIP_DIR_DEBUG,
"Skipping to termination path\n");
return 0;
}
gossip_debug(GOSSIP_DIR_DEBUG,
"orangefs_readdir called on %pd (pos=%llu)\n",
dentry, llu(pos));
memset(&readdir_response, 0, sizeof(readdir_response));
new_op = op_alloc(ORANGEFS_VFS_OP_READDIR);
if (!new_op)
return -ENOMEM;
/*
* Only the indices are shared. No memory is actually shared, but the
* mechanism is used.
*/
new_op->uses_shared_memory = 1;
new_op->upcall.req.readdir.refn = orangefs_inode->refn;
new_op->upcall.req.readdir.max_dirent_count =
ORANGEFS_MAX_DIRENT_COUNT_READDIR;
gossip_debug(GOSSIP_DIR_DEBUG,
"%s: upcall.req.readdir.refn.khandle: %pU\n",
__func__,
&new_op->upcall.req.readdir.refn.khandle);
new_op->upcall.req.readdir.token = *ptoken;
get_new_buffer_index:
buffer_index = orangefs_readdir_index_get();
if (buffer_index < 0) {
ret = buffer_index;
gossip_lerr("orangefs_readdir: orangefs_readdir_index_get() failure (%d)\n",
ret);
goto out_free_op;
}
new_op->upcall.req.readdir.buf_index = buffer_index;
ret = service_operation(new_op,
"orangefs_readdir",
get_interruptible_flag(dentry->d_inode));
gossip_debug(GOSSIP_DIR_DEBUG,
"Readdir downcall status is %d. ret:%d\n",
new_op->downcall.status,
ret);
orangefs_readdir_index_put(buffer_index);
if (ret == -EAGAIN && op_state_purged(new_op)) {
/* Client-core indices are invalid after it restarted. */
gossip_debug(GOSSIP_DIR_DEBUG,
"%s: Getting new buffer_index for retry of readdir..\n",
__func__);
goto get_new_buffer_index;
}
if (ret == -EIO && op_state_purged(new_op)) {
gossip_err("%s: Client is down. Aborting readdir call.\n",
__func__);
goto out_free_op;
}
if (ret < 0 || new_op->downcall.status != 0) {
gossip_debug(GOSSIP_DIR_DEBUG,
"Readdir request failed. Status:%d\n",
new_op->downcall.status);
if (ret >= 0)
ret = new_op->downcall.status;
goto out_free_op;
}
dents_buf = new_op->downcall.trailer_buf;
if (dents_buf == NULL) {
gossip_err("Invalid NULL buffer in readdir response\n");
ret = -ENOMEM;
goto out_free_op;
}
bytes_decoded = decode_dirents(dents_buf, new_op->downcall.trailer_size,
&readdir_response);
if (bytes_decoded < 0) {
ret = bytes_decoded;
gossip_err("Could not decode readdir from buffer %d\n", ret);
goto out_vfree;
}
if (bytes_decoded != new_op->downcall.trailer_size) {
gossip_err("orangefs_readdir: # bytes decoded (%ld) "
"!= trailer size (%ld)\n",
bytes_decoded,
(long)new_op->downcall.trailer_size);
ret = -EINVAL;
goto out_destroy_handle;
}
/*
* orangefs doesn't actually store dot and dot-dot, but
* we need to have them represented.
*/
if (pos == 0) {
ino = get_ino_from_khandle(dentry->d_inode);
gossip_debug(GOSSIP_DIR_DEBUG,
"%s: calling dir_emit of \".\" with pos = %llu\n",
__func__,
llu(pos));
ret = dir_emit(ctx, ".", 1, ino, DT_DIR);
pos += 1;
}
if (pos == 1) {
ino = get_parent_ino_from_dentry(dentry);
gossip_debug(GOSSIP_DIR_DEBUG,
"%s: calling dir_emit of \"..\" with pos = %llu\n",
__func__,
llu(pos));
ret = dir_emit(ctx, "..", 2, ino, DT_DIR);
pos += 1;
}
/*
* we stored ORANGEFS_ITERATE_NEXT in ctx->pos last time around
* to prevent "finding" dot and dot-dot on any iteration
* other than the first.
*/
if (ctx->pos == ORANGEFS_ITERATE_NEXT)
ctx->pos = 0;
gossip_debug(GOSSIP_DIR_DEBUG,
"%s: dirent_outcount:%d:\n",
__func__,
readdir_response.orangefs_dirent_outcount);
for (i = ctx->pos;
i < readdir_response.orangefs_dirent_outcount;
i++) {
len = readdir_response.dirent_array[i].d_length;
current_entry = readdir_response.dirent_array[i].d_name;
current_ino = orangefs_khandle_to_ino(
&readdir_response.dirent_array[i].khandle);
gossip_debug(GOSSIP_DIR_DEBUG,
"calling dir_emit for %s with len %d"
", ctx->pos %ld\n",
current_entry,
len,
(unsigned long)ctx->pos);
/*
* type is unknown. We don't return object type
* in the dirent_array. This leaves getdents
* clueless about type.
*/
ret =
dir_emit(ctx, current_entry, len, current_ino, DT_UNKNOWN);
if (!ret)
break;
ctx->pos++;
gossip_debug(GOSSIP_DIR_DEBUG,
"%s: ctx->pos:%lld\n",
__func__,
lld(ctx->pos));
}
/*
* we ran all the way through the last batch, set up for
* getting another batch...
*/
if (ret) {
*ptoken = readdir_response.token;
ctx->pos = ORANGEFS_ITERATE_NEXT;
}
/*
* Did we hit the end of the directory?
*/
if (readdir_response.token == ORANGEFS_READDIR_END) {
gossip_debug(GOSSIP_DIR_DEBUG,
"End of dir detected; setting ctx->pos to ORANGEFS_READDIR_END.\n");
ctx->pos = ORANGEFS_READDIR_END;
}
out_destroy_handle:
/* kfree(NULL) is safe */
kfree(readdir_response.dirent_array);
out_vfree:
gossip_debug(GOSSIP_DIR_DEBUG, "vfree %p\n", dents_buf);
vfree(dents_buf);
out_free_op:
op_release(new_op);
gossip_debug(GOSSIP_DIR_DEBUG, "orangefs_readdir returning %d\n", ret);
return ret;
}
static int orangefs_dir_open(struct inode *inode, struct file *file)
{
__u64 *ptoken;
file->private_data = kmalloc(sizeof(__u64), GFP_KERNEL);
if (!file->private_data)
return -ENOMEM;
ptoken = file->private_data;
*ptoken = ORANGEFS_READDIR_START;
return 0;
}
static int orangefs_dir_release(struct inode *inode, struct file *file)
{
orangefs_flush_inode(inode);
kfree(file->private_data);
return 0;
}
/** ORANGEFS implementation of VFS directory operations */
const struct file_operations orangefs_dir_operations = {
.read = generic_read_dir,
.iterate = orangefs_readdir,
.open = orangefs_dir_open,
.release = orangefs_dir_release,
};