/*
- * (C) 2001 Clemson University and The University of Chicago
- *
- * See COPYING in top-level directory.
+ * Copyright 2017 Omnibond Systems, L.L.C.
*/
#include "protocol.h"
#include "orangefs-kernel.h"
#include "orangefs-bufmap.h"
+struct orangefs_dir_part {
+ struct orangefs_dir_part *next;
+ size_t len;
+};
+
+struct orangefs_dir {
+ __u64 token;
+ struct orangefs_dir_part *part;
+ loff_t end;
+ int error;
+};
+
+#define PART_SHIFT (24)
+#define PART_SIZE (1<<24)
+#define PART_MASK (~(PART_SIZE - 1))
+
/*
- * 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.
+ * There can be up to 512 directory entries. Each entry is encoded as
+ * follows:
+ * 4 bytes: string size (n)
+ * n bytes: string
+ * 1 byte: trailing zero
+ * padding to 8 bytes
+ * 16 bytes: khandle
+ * padding to 8 bytes
+ *
+ * The trailer_buf starts with a struct orangefs_readdir_response_s
+ * which must be skipped to get to the directory data.
+ *
+ * The data which is received from the userspace daemon is termed a
+ * part and is stored in a linked list in case more than one part is
+ * needed for a large directory.
+ *
+ * The position pointer (ctx->pos) encodes the part and offset on which
+ * to begin reading at. Bits above PART_SHIFT encode the part and bits
+ * below PART_SHIFT encode the offset. Parts are stored in a linked
+ * list which grows as data is received from the server. The overhead
+ * associated with managing the list is presumed to be small compared to
+ * the overhead of communicating with the server.
+ *
+ * As data is received from the server, it is placed at the end of the
+ * part list. Data is parsed from the current position as it is needed.
+ * When data is determined to be corrupt, it is either because the
+ * userspace component has sent back corrupt data or because the file
+ * pointer has been moved to an invalid location. Since the two cannot
+ * be differentiated, return EIO.
+ *
+ * Part zero is synthesized to contains `.' and `..'. Part one is the
+ * first part of the part list.
*/
-static long decode_dirents(char *ptr, size_t size,
- struct orangefs_readdir_response_s *readdir)
+
+static int do_readdir(struct orangefs_inode_s *oi,
+ struct orangefs_dir *od, struct dentry *dentry,
+ struct orangefs_kernel_op_s *op)
{
- 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;
- }
+ struct orangefs_readdir_response_s *resp;
+ int bufi, r;
- 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;
- }
+ /*
+ * Despite the badly named field, readdir does not use shared
+ * memory. However, there are a limited number of readdir
+ * slots, which must be allocated here. This flag simply tells
+ * the op scheduler to return the op here for retry.
+ */
+ op->uses_shared_memory = 1;
+ op->upcall.req.readdir.refn = oi->refn;
+ op->upcall.req.readdir.token = od->token;
+ op->upcall.req.readdir.max_dirent_count =
+ ORANGEFS_MAX_DIRENT_COUNT_READDIR;
- 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;
+again:
+ bufi = orangefs_readdir_index_get();
+ if (bufi < 0) {
+ od->error = bufi;
+ return bufi;
}
- 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;
- }
+ op->upcall.req.readdir.buf_index = bufi;
- len = *(__u32 *)buf;
- if ((len < 1) || (len > ORANGEFS_NAME_MAX)) {
- gossip_err("%s: len:%d:\n", __func__, len);
- ret = -EINVAL;
- goto free;
- }
+ r = service_operation(op, "orangefs_readdir",
+ get_interruptible_flag(dentry->d_inode));
- gossip_debug(GOSSIP_DIR_DEBUG,
- "%s: size:%zu: len:%d:\n",
- __func__,
- size,
- len);
+ orangefs_readdir_index_put(bufi);
- readdir->dirent_array[i].d_name = buf + sizeof_u32;
- readdir->dirent_array[i].d_length = len;
+ if (op_state_purged(op)) {
+ if (r == -EAGAIN) {
+ vfree(op->downcall.trailer_buf);
+ goto again;
+ } else if (r == -EIO) {
+ vfree(op->downcall.trailer_buf);
+ od->error = r;
+ return r;
+ }
+ }
- /*
- * 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);
+ if (r < 0) {
+ vfree(op->downcall.trailer_buf);
+ od->error = r;
+ return r;
+ } else if (op->downcall.status) {
+ vfree(op->downcall.trailer_buf);
+ od->error = op->downcall.status;
+ return op->downcall.status;
+ }
- /*
- * 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;
+ /*
+ * The maximum size is size per entry times the 512 entries plus
+ * the header. This is well under the limit.
+ */
+ if (op->downcall.trailer_size > PART_SIZE) {
+ vfree(op->downcall.trailer_buf);
+ od->error = -EIO;
+ return -EIO;
+ }
- buf += aligned_len;
+ resp = (struct orangefs_readdir_response_s *)
+ op->downcall.trailer_buf;
+ od->token = resp->token;
+ return 0;
+}
- readdir->dirent_array[i].khandle =
- *(struct orangefs_khandle *) buf;
- buf += khandle_size;
+static int parse_readdir(struct orangefs_dir *od,
+ struct orangefs_kernel_op_s *op)
+{
+ struct orangefs_dir_part *part, *new;
+ size_t count;
+
+ count = 1;
+ part = od->part;
+ while (part) {
+ count++;
+ if (part->next)
+ part = part->next;
+ else
+ break;
}
- 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;
+ new = (void *)op->downcall.trailer_buf;
+ new->next = NULL;
+ new->len = op->downcall.trailer_size -
+ sizeof(struct orangefs_readdir_response_s);
+ if (!od->part)
+ od->part = new;
+ else
+ part->next = new;
+ count++;
+ od->end = count << PART_SHIFT;
-out:
- return ret;
+ return 0;
}
-/*
- * Read directory entries from an instance of an open directory.
- */
-static int orangefs_readdir(struct file *file, struct dir_context *ctx)
+static int orangefs_dir_more(struct orangefs_inode_s *oi,
+ struct orangefs_dir *od, struct dentry *dentry)
{
- 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;
+ struct orangefs_kernel_op_s *op;
+ int r;
+
+ op = op_alloc(ORANGEFS_VFS_OP_READDIR);
+ if (!op) {
+ od->error = -ENOMEM;
+ return -ENOMEM;
+ }
+ r = do_readdir(oi, od, dentry, op);
+ if (r) {
+ od->error = r;
+ goto out;
+ }
+ r = parse_readdir(od, op);
+ if (r) {
+ od->error = r;
+ goto out;
}
- gossip_debug(GOSSIP_DIR_DEBUG,
- "orangefs_readdir called on %pd (pos=%llu)\n",
- dentry, llu(pos));
+ od->error = 0;
+out:
+ op_release(op);
+ return od->error;
+}
- memset(&readdir_response, 0, sizeof(readdir_response));
+static int fill_from_part(struct orangefs_dir_part *part,
+ struct dir_context *ctx)
+{
+ const int offset = sizeof(struct orangefs_readdir_response_s);
+ struct orangefs_khandle *khandle;
+ __u32 *len, padlen;
+ loff_t i;
+ char *s;
+ i = ctx->pos & ~PART_MASK;
- new_op = op_alloc(ORANGEFS_VFS_OP_READDIR);
- if (!new_op)
- return -ENOMEM;
+ /* The file offset from userspace is too large. */
+ if (i > part->len)
+ return 1;
/*
- * Only the indices are shared. No memory is actually shared, but the
- * mechanism is used.
+ * If the seek pointer is positioned just before an entry it
+ * should find the next entry.
*/
- 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);
+ if (i % 8)
+ i = i + (8 - i%8)%8;
- 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;
+ while (i < part->len) {
+ if (part->len < i + sizeof *len)
+ break;
+ len = (void *)part + offset + i;
+ /*
+ * len is the size of the string itself. padlen is the
+ * total size of the encoded string.
+ */
+ padlen = (sizeof *len + *len + 1) +
+ (8 - (sizeof *len + *len + 1)%8)%8;
+ if (part->len < i + padlen + sizeof *khandle)
+ goto next;
+ s = (void *)part + offset + i + sizeof *len;
+ if (s[*len] != 0)
+ goto next;
+ khandle = (void *)part + offset + i + padlen;
+ if (!dir_emit(ctx, s, *len,
+ orangefs_khandle_to_ino(khandle),
+ DT_UNKNOWN))
+ return 0;
+ i += padlen + sizeof *khandle;
+ i = i + (8 - i%8)%8;
+ BUG_ON(i > part->len);
+ ctx->pos = (ctx->pos & PART_MASK) | i;
+ continue;
+next:
+ i += 8;
}
- new_op->upcall.req.readdir.buf_index = buffer_index;
-
- ret = service_operation(new_op,
- "orangefs_readdir",
- get_interruptible_flag(dentry->d_inode));
+ return 1;
+}
- gossip_debug(GOSSIP_DIR_DEBUG,
- "Readdir downcall status is %d. ret:%d\n",
- new_op->downcall.status,
- ret);
+static int orangefs_dir_fill(struct orangefs_inode_s *oi,
+ struct orangefs_dir *od, struct dentry *dentry,
+ struct dir_context *ctx)
+{
+ struct orangefs_dir_part *part;
+ size_t count;
- orangefs_readdir_index_put(buffer_index);
+ count = ((ctx->pos & PART_MASK) >> PART_SHIFT) - 1;
- 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;
+ part = od->part;
+ while (part->next && count) {
+ count--;
+ part = part->next;
}
-
- if (ret == -EIO && op_state_purged(new_op)) {
- gossip_err("%s: Client is down. Aborting readdir call.\n",
- __func__);
- goto out_free_op;
+ /* This means the userspace file offset is invalid. */
+ if (count) {
+ od->error = -EIO;
+ return -EIO;
}
- 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;
+ while (part && part->len) {
+ int r;
+ r = fill_from_part(part, ctx);
+ if (r < 0) {
+ od->error = r;
+ return r;
+ } else if (r == 0) {
+ /* Userspace buffer is full. */
+ break;
+ } else {
+ /*
+ * The part ran out of data. Move to the next
+ * part. */
+ ctx->pos = (ctx->pos & PART_MASK) +
+ (1 << PART_SHIFT);
+ part = part->next;
+ }
}
+ return 0;
+}
- 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;
+static loff_t orangefs_dir_llseek(struct file *file, loff_t offset,
+ int whence)
+{
+ struct orangefs_dir *od = file->private_data;
+ /*
+ * Delete the stored data so userspace sees new directory
+ * entries.
+ */
+ if (!whence && offset < od->end) {
+ struct orangefs_dir_part *part = od->part;
+ while (part) {
+ struct orangefs_dir_part *next = part->next;
+ vfree(part);
+ part = next;
+ }
+ od->token = ORANGEFS_ITERATE_START;
+ od->part = NULL;
+ od->end = 1 << PART_SHIFT;
}
+ return default_llseek(file, offset, whence);
+}
- 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;
- }
+static int orangefs_dir_iterate(struct file *file,
+ struct dir_context *ctx)
+{
+ struct orangefs_inode_s *oi;
+ struct orangefs_dir *od;
+ struct dentry *dentry;
+ int r;
- 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;
- }
+ dentry = file->f_path.dentry;
+ oi = ORANGEFS_I(dentry->d_inode);
+ od = file->private_data;
- /*
- * 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 (od->error)
+ return od->error;
- 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;
+ if (ctx->pos == 0) {
+ if (!dir_emit_dot(file, ctx))
+ return 0;
+ ctx->pos++;
+ }
+ if (ctx->pos == 1) {
+ if (!dir_emit_dotdot(file, ctx))
+ return 0;
+ ctx->pos = 1 << PART_SHIFT;
}
/*
- * 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.
+ * The seek position is in the first synthesized part but is not
+ * valid.
*/
- 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));
+ if ((ctx->pos & PART_MASK) == 0)
+ return -EIO;
- }
+ r = 0;
/*
- * we ran all the way through the last batch, set up for
- * getting another batch...
+ * Must read more if the user has sought past what has been read
+ * so far. Stop a user who has sought past the end.
*/
- if (ret) {
- *ptoken = readdir_response.token;
- ctx->pos = ORANGEFS_ITERATE_NEXT;
+ while (od->token != ORANGEFS_ITERATE_END &&
+ ctx->pos > od->end) {
+ r = orangefs_dir_more(oi, od, dentry);
+ if (r)
+ return r;
+ }
+ if (od->token == ORANGEFS_ITERATE_END && ctx->pos > od->end)
+ return -EIO;
+
+ /* Then try to fill if there's any left in the buffer. */
+ if (ctx->pos < od->end) {
+ r = orangefs_dir_fill(oi, od, dentry, ctx);
+ if (r)
+ return r;
}
- /*
- * 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;
+ /* Finally get some more and try to fill. */
+ if (od->token != ORANGEFS_ITERATE_END) {
+ r = orangefs_dir_more(oi, od, dentry);
+ if (r)
+ return r;
+ r = orangefs_dir_fill(oi, od, dentry, ctx);
}
-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;
+ return r;
}
static int orangefs_dir_open(struct inode *inode, struct file *file)
{
- __u64 *ptoken;
-
- file->private_data = kmalloc(sizeof(__u64), GFP_KERNEL);
+ struct orangefs_dir *od;
+ file->private_data = kmalloc(sizeof(struct orangefs_dir),
+ GFP_KERNEL);
if (!file->private_data)
return -ENOMEM;
-
- ptoken = file->private_data;
- *ptoken = ORANGEFS_READDIR_START;
+ od = file->private_data;
+ od->token = ORANGEFS_ITERATE_START;
+ od->part = NULL;
+ od->end = 1 << PART_SHIFT;
+ od->error = 0;
return 0;
}
static int orangefs_dir_release(struct inode *inode, struct file *file)
{
+ struct orangefs_dir *od = file->private_data;
+ struct orangefs_dir_part *part = od->part;
orangefs_flush_inode(inode);
- kfree(file->private_data);
+ while (part) {
+ struct orangefs_dir_part *next = part->next;
+ vfree(part);
+ part = next;
+ }
+ kfree(od);
return 0;
}
-/** ORANGEFS implementation of VFS directory operations */
const struct file_operations orangefs_dir_operations = {
+ .llseek = orangefs_dir_llseek,
.read = generic_read_dir,
- .iterate = orangefs_readdir,
+ .iterate = orangefs_dir_iterate,
.open = orangefs_dir_open,
- .release = orangefs_dir_release,
+ .release = orangefs_dir_release
};
projects / karo-tx-linux.git / blobdiff