+++ /dev/null
-/*
- * Unix SMB/CIFS implementation.
- *
- * Support for OneFS bulk directory enumeration API
- *
- * Copyright (C) Steven Danneman, 2009
- *
- * 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; either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will 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, see <http://www.gnu.org/licenses/>.
- */
-
-#include "includes.h"
-#include "smbd/smbd.h"
-#include "onefs.h"
-#include "onefs_config.h"
-
-#include <ifs/ifs_syscalls.h>
-#include <isi_util/isi_dir.h>
-
-/* The OneFS filesystem provides a readdirplus() syscall, equivalent to the
- * NFSv3 PDU, which retrieves bulk directory listings with stat information
- * in a single syscall.
- *
- * This file hides this bulk interface underneath Samba's very POSIX like
- * opendir/readdir/telldir VFS interface. This is done to provide a
- * significant performance improvement when listing the contents of large
- * directories, which also require file meta information. ie a typical
- * Windows Explorer request.
- */
-
-#define RDP_RESUME_KEY_START 0x1
-
-#define RDP_BATCH_SIZE 128
-#define RDP_DIRENTRIES_SIZE ((size_t)(RDP_BATCH_SIZE * sizeof(struct dirent)))
-
-static char *rdp_direntries = NULL;
-static struct stat *rdp_stats = NULL;
-static uint64_t *rdp_cookies = NULL;
-
-struct rdp_dir_state {
- struct rdp_dir_state *next, *prev;
- SMB_STRUCT_DIR *dirp;
- char *direntries_cursor; /* cursor to last returned direntry in cache */
- size_t stat_count; /* number of entries stored in the cache */
- size_t stat_cursor; /* cursor to last returned stat in the cache */
- uint64_t resume_cookie; /* cookie from the last entry returned from the
- cache */
-};
-
-static struct rdp_dir_state *dirstatelist = NULL;
-
-SMB_STRUCT_DIR *rdp_last_dirp = NULL;
-
-/**
- * Given a DIR pointer, return our internal state.
- *
- * This function also tells us whether the given DIR is the same as we saw
- * during the last call. Because we use a single globally allocated buffer
- * for readdirplus entries we must check every call into this API to see if
- * it's for the same directory listing, or a new one. If it's the same we can
- * maintain our current cached entries, otherwise we must go to the kernel.
- *
- * @return 0 on success, 1 on failure
- */
-static int
-rdp_retrieve_dir_state(SMB_STRUCT_DIR *dirp, struct rdp_dir_state **dir_state,
- bool *same_as_last)
-{
- struct rdp_dir_state *dsp;
-
- /* Is this directory the same as the last call */
- *same_as_last = (dirp == rdp_last_dirp);
-
- for(dsp = dirstatelist; dsp; dsp = dsp->next)
- if (dsp->dirp == dirp) {
- *dir_state = dsp;
- return 0;
- }
-
- /* Couldn't find existing dir_state for the given directory
- * pointer. */
- return 1;
-}
-
-/**
- * Initialize the global readdirplus buffers.
- *
- * These same buffers are used for all calls into readdirplus.
- *
- * @return 0 on success, errno value on failure
- */
-static int
-rdp_init(struct rdp_dir_state *dsp)
-{
- /* Unfortunately, there is no good way to free these buffers. If we
- * allocated and freed for every DIR handle performance would be
- * adversely affected. For now these buffers will be leaked and only
- * freed when the smbd process dies. */
- if (!rdp_direntries) {
- rdp_direntries = SMB_MALLOC(RDP_DIRENTRIES_SIZE);
- if (!rdp_direntries)
- return ENOMEM;
- }
-
- if (!rdp_stats) {
- rdp_stats =
- SMB_MALLOC(RDP_BATCH_SIZE * sizeof(struct stat));
- if (!rdp_stats)
- return ENOMEM;
- }
-
- if (!rdp_cookies) {
- rdp_cookies = SMB_MALLOC(RDP_BATCH_SIZE * sizeof(uint64_t));
- if (!rdp_cookies)
- return ENOMEM;
- }
-
- dsp->direntries_cursor = rdp_direntries + RDP_DIRENTRIES_SIZE;
- dsp->stat_count = RDP_BATCH_SIZE;
- dsp->stat_cursor = RDP_BATCH_SIZE;
- dsp->resume_cookie = RDP_RESUME_KEY_START;
-
- return 0;
-}
-
-/**
- * Call into readdirplus() to refill our global dirent cache.
- *
- * This function also resets all cursors back to the beginning of the cache.
- * All stat buffers are retrieved by following symlinks.
- *
- * @return number of entries retrieved, -1 on error
- */
-static int
-rdp_fill_cache(struct rdp_dir_state *dsp)
-{
- int nread, dirfd;
-
- dirfd = dirfd(dsp->dirp);
- if (dirfd < 0) {
- DEBUG(1, ("Could not retrieve fd for DIR\n"));
- return -1;
- }
-
- /* Resize the stat_count to grab as many entries as possible */
- dsp->stat_count = RDP_BATCH_SIZE;
-
- DEBUG(9, ("Calling readdirplus() with DIR %p, dirfd: %d, "
- "resume_cookie %#llx, size_to_read: %zu, "
- "direntries_size: %zu, stat_count: %u\n",
- dsp->dirp, dirfd, dsp->resume_cookie, RDP_BATCH_SIZE,
- RDP_DIRENTRIES_SIZE, dsp->stat_count));
-
- nread = readdirplus(dirfd,
- RDP_FOLLOW,
- &dsp->resume_cookie,
- RDP_BATCH_SIZE,
- rdp_direntries,
- RDP_DIRENTRIES_SIZE,
- &dsp->stat_count,
- rdp_stats,
- rdp_cookies);
- if (nread < 0) {
- DEBUG(1, ("Error calling readdirplus(): %s\n",
- strerror(errno)));
- return -1;
- }
-
- DEBUG(9, ("readdirplus() returned %u entries from DIR %p\n",
- dsp->stat_count, dsp->dirp));
-
- dsp->direntries_cursor = rdp_direntries;
- dsp->stat_cursor = 0;
-
- return nread;
-}
-
-/**
- * Create a dir_state to track an open directory that we're enumerating.
- *
- * This utility function is globally accessible for use by other parts of the
- * onefs.so module to initialize a dir_state when a directory is opened through
- * a path other than the VFS layer.
- *
- * @return 0 on success and errno on failure
- *
- * @note: Callers of this function MUST cleanup the dir_state through a proper
- * call to VFS_CLOSEDIR().
- */
-int
-onefs_rdp_add_dir_state(connection_struct *conn, SMB_STRUCT_DIR *dirp)
-{
- int ret = 0;
- struct rdp_dir_state *dsp = NULL;
-
- /* No-op if readdirplus is disabled */
- if (!lp_parm_bool(SNUM(conn), PARM_ONEFS_TYPE,
- PARM_USE_READDIRPLUS, PARM_USE_READDIRPLUS_DEFAULT))
- {
- return 0;
- }
-
- /* Create a struct dir_state */
- dsp = SMB_MALLOC_P(struct rdp_dir_state);
- if (!dsp) {
- DEBUG(0, ("Error allocating struct rdp_dir_state.\n"));
- return ENOMEM;
- }
-
- /* Initialize the dir_state structure and add it to the list */
- ret = rdp_init(dsp);
- if (ret) {
- DEBUG(0, ("Error initializing readdirplus() buffers: %s\n",
- strerror(ret)));
- return ret;
- }
-
- /* Set the SMB_STRUCT_DIR in the dsp */
- dsp->dirp = dirp;
-
- DLIST_ADD(dirstatelist, dsp);
-
- return 0;
-}
-
-/**
- * Open a directory for enumeration.
- *
- * Create a state struct to track the state of this directory for the life
- * of this open.
- *
- * @param[in] handle vfs handle given in most VFS calls
- * @param[in] fname filename of the directory to open
- * @param[in] mask unused
- * @param[in] attr unused
- *
- * @return DIR pointer, NULL if directory does not exist, NULL on error
- */
-SMB_STRUCT_DIR *
-onefs_opendir(vfs_handle_struct *handle, const char *fname, const char *mask,
- uint32 attr)
-{
- int ret = 0;
- SMB_STRUCT_DIR *ret_dirp;
-
- /* Fallback to default system routines if readdirplus is disabled */
- if (!lp_parm_bool(SNUM(handle->conn), PARM_ONEFS_TYPE,
- PARM_USE_READDIRPLUS, PARM_USE_READDIRPLUS_DEFAULT))
- {
- return SMB_VFS_NEXT_OPENDIR(handle, fname, mask, attr);
- }
-
- /* Open the directory */
- ret_dirp = SMB_VFS_NEXT_OPENDIR(handle, fname, mask, attr);
- if (!ret_dirp) {
- DEBUG(3, ("Unable to open directory: %s\n", fname));
- return NULL;
- }
-
- /* Create the dir_state struct and add it to the list */
- ret = onefs_rdp_add_dir_state(handle->conn, ret_dirp);
- if (ret) {
- DEBUG(0, ("Error adding dir_state to the list\n"));
- return NULL;
- }
-
- DEBUG(9, ("Opened handle on directory: \"%s\", DIR %p\n",
- fname, ret_dirp));
-
- return ret_dirp;
-}
-
-/**
- * Retrieve one direntry and optional stat buffer from our readdir cache.
- *
- * Increment the internal resume cookie, and refresh the cache from the
- * kernel if necessary.
- *
- * The cache cursor tracks the last entry which was successfully returned
- * to a caller of onefs_readdir(). When a new entry is requested, this
- * function first increments the cursor, then returns that entry.
- *
- * @param[in] handle vfs handle given in most VFS calls
- * @param[in] dirp system DIR handle to retrieve direntries from
- * @param[in/out] sbuf optional stat buffer to fill, this can be NULL
- *
- * @return dirent structure, NULL if at the end of the directory, NULL on error
- */
-SMB_STRUCT_DIRENT *
-onefs_readdir(vfs_handle_struct *handle, SMB_STRUCT_DIR *dirp,
- SMB_STRUCT_STAT *sbuf)
-{
- struct rdp_dir_state *dsp = NULL;
- SMB_STRUCT_DIRENT *ret_direntp;
- bool same_as_last, filled_cache = false;
- int ret = -1;
-
- /* Set stat invalid in-case we error out */
- if (sbuf)
- SET_STAT_INVALID(*sbuf);
-
- /* Fallback to default system routines if readdirplus is disabled */
- if (!lp_parm_bool(SNUM(handle->conn), PARM_ONEFS_TYPE,
- PARM_USE_READDIRPLUS, PARM_USE_READDIRPLUS_DEFAULT))
- {
- return readdir(dirp);
- }
-
- /* Retrieve state based off DIR handle */
- ret = rdp_retrieve_dir_state(dirp, &dsp, &same_as_last);
- if (ret) {
- DEBUG(1, ("Could not retrieve dir_state struct for "
- "SMB_STRUCT_DIR pointer.\n"));
- ret_direntp = NULL;
- goto end;
- }
-
- /* DIR is the same, current buffer and cursors are valid.
- * Check if there are any entries left in our current cache. */
- if (same_as_last) {
- if (dsp->stat_cursor == dsp->stat_count - 1) {
- /* Cache is empty, refill from kernel */
- ret = rdp_fill_cache(dsp);
- if (ret <= 0) {
- ret_direntp = NULL;
- goto end;
- }
- filled_cache = true;
- }
- } else {
- /* DIR is different from last call, reset all buffers and
- * cursors, and refill the global cache from the new DIR */
- ret = rdp_fill_cache(dsp);
- if (ret <= 0) {
- ret_direntp = NULL;
- goto end;
- }
- filled_cache = true;
- DEBUG(8, ("Switched global rdp cache to new DIR entry.\n"));
- }
-
- /* If we just filled the cache we treat that action as the cursor
- * increment as the resume cookie used belonged to the previous
- * directory entry. If the cache has not changed we first increment
- * our cursor, then return the next entry */
- if (!filled_cache) {
- dsp->direntries_cursor +=
- ((SMB_STRUCT_DIRENT *)dsp->direntries_cursor)->d_reclen;
- dsp->stat_cursor++;
- }
-
- /* The resume_cookie stored here purposely differs based on whether we
- * just filled the cache. The resume cookie stored must always provide
- * the next direntry, in case the cache is reloaded on every
- * onefs_readdir() */
- dsp->resume_cookie = rdp_cookies[dsp->stat_cursor];
-
- /* Return an entry from cache */
- ret_direntp = ((SMB_STRUCT_DIRENT *)dsp->direntries_cursor);
- if (sbuf) {
- struct stat onefs_sbuf;
-
- onefs_sbuf = rdp_stats[dsp->stat_cursor];
- init_stat_ex_from_onefs_stat(sbuf, &onefs_sbuf);
-
- /* readdirplus() sets st_ino field to 0, if it was
- * unable to retrieve stat information for that
- * particular directory entry. */
- if (sbuf->st_ex_ino == 0)
- SET_STAT_INVALID(*sbuf);
- }
-
- DEBUG(9, ("Read from DIR %p, direntry: \"%s\", resume cookie: %#llx, "
- "cache cursor: %zu, cache count: %zu\n",
- dsp->dirp, ret_direntp->d_name, dsp->resume_cookie,
- dsp->stat_cursor, dsp->stat_count));
-
- /* FALLTHROUGH */
-end:
- /* Set rdp_last_dirp at the end of every VFS call where the cache was
- * reloaded */
- rdp_last_dirp = dirp;
- return ret_direntp;
-}
-
-/**
- * Set the location of the next direntry to be read via onefs_readdir().
- *
- * This function should only pass in locations retrieved from onefs_telldir().
- *
- * @param[in] handle vfs handle given in most VFS calls
- * @param[in] dirp system DIR handle to set offset on
- * @param[in] offset into the directory to resume reading from
- *
- * @return no return value
- */
-void
-onefs_seekdir(vfs_handle_struct *handle, SMB_STRUCT_DIR *dirp, long offset)
-{
- struct rdp_dir_state *dsp = NULL;
- bool same_as_last;
- uint64_t resume_cookie = 0;
- int ret = -1;
-
- /* Fallback to default system routines if readdirplus is disabled */
- if (!lp_parm_bool(SNUM(handle->conn), PARM_ONEFS_TYPE,
- PARM_USE_READDIRPLUS, PARM_USE_READDIRPLUS_DEFAULT))
- {
- return sys_seekdir(dirp, offset);
- }
-
- /* Validate inputs */
- if (offset < 0) {
- DEBUG(1, ("Invalid offset %ld passed.\n", offset));
- return;
- }
-
- /* Retrieve state based off DIR handle */
- ret = rdp_retrieve_dir_state(dirp, &dsp, &same_as_last);
- if (ret) {
- DEBUG(1, ("Could not retrieve dir_state struct for "
- "SMB_STRUCT_DIR pointer.\n"));
- /* XXX: we can't return an error, should we ABORT rather than
- * return without actually seeking? */
- return;
- }
-
- /* Convert offset to resume_cookie */
- resume_cookie = rdp_offset31_to_cookie63(offset);
-
- DEBUG(9, ("Seek DIR %p, offset: %ld, resume_cookie: %#llx\n",
- dsp->dirp, offset, resume_cookie));
-
- /* TODO: We could check if the resume_cookie is already in the cache
- * through a linear search. This would allow us to avoid the cost of
- * flushing the cache. Frequently, the seekdir offset will only be
- * one entry before the current cache cursor. However, usually
- * VFS_SEEKDIR() is only called at the end of a TRAND2_FIND read and
- * we'll flush the cache at the beginning of the next PDU anyway. Some
- * analysis should be done to see if this enhancement would provide
- * better performance. */
-
- /* Set the resume cookie and indicate that the cache should be reloaded
- * on next read */
- dsp->resume_cookie = resume_cookie;
- rdp_last_dirp = NULL;
-
- return;
-}
-
-/**
- * Returns the location of the next direntry to be read via onefs_readdir().
- *
- * This value can be passed into onefs_seekdir().
- *
- * @param[in] handle vfs handle given in most VFS calls
- * @param[in] dirp system DIR handle to set offset on
- *
- * @return offset into the directory to resume reading from
- */
-long
-onefs_telldir(vfs_handle_struct *handle, SMB_STRUCT_DIR *dirp)
-{
- struct rdp_dir_state *dsp = NULL;
- bool same_as_last;
- long offset;
- int ret = -1;
-
- /* Fallback to default system routines if readdirplus is disabled */
- if (!lp_parm_bool(SNUM(handle->conn), PARM_ONEFS_TYPE,
- PARM_USE_READDIRPLUS, PARM_USE_READDIRPLUS_DEFAULT))
- {
- return sys_telldir(dirp);
- }
-
- /* Retrieve state based off DIR handle */
- ret = rdp_retrieve_dir_state(dirp, &dsp, &same_as_last);
- if (ret) {
- DEBUG(1, ("Could not retrieve dir_state struct for "
- "SMB_STRUCT_DIR pointer.\n"));
- return -1;
- }
-
- /* Convert resume_cookie to offset */
- offset = rdp_cookie63_to_offset31(dsp->resume_cookie);
- if (offset < 0) {
- DEBUG(1, ("Unable to convert resume_cookie: %#llx to a "
- "suitable 32-bit offset value. Error: %s\n",
- dsp->resume_cookie, strerror(errno)));
- return -1;
- }
-
- DEBUG(9, ("Seek DIR %p, offset: %ld, resume_cookie: %#llx\n",
- dsp->dirp, offset, dsp->resume_cookie));
-
- return offset;
-}
-
-/**
- * Set the next direntry to be read via onefs_readdir() to the beginning of the
- * directory.
- *
- * @param[in] handle vfs handle given in most VFS calls
- * @param[in] dirp system DIR handle to set offset on
- *
- * @return no return value
- */
-void
-onefs_rewinddir(vfs_handle_struct *handle, SMB_STRUCT_DIR *dirp)
-{
- struct rdp_dir_state *dsp = NULL;
- bool same_as_last;
- int ret = -1;
-
- /* Fallback to default system routines if readdirplus is disabled */
- if (!lp_parm_bool(SNUM(handle->conn), PARM_ONEFS_TYPE,
- PARM_USE_READDIRPLUS, PARM_USE_READDIRPLUS_DEFAULT))
- {
- return sys_rewinddir(dirp);
- }
-
- /* Retrieve state based off DIR handle */
- ret = rdp_retrieve_dir_state(dirp, &dsp, &same_as_last);
- if (ret) {
- DEBUG(1, ("Could not retrieve dir_state struct for "
- "SMB_STRUCT_DIR pointer.\n"));
- return;
- }
-
- /* Reset location and resume key to beginning */
- ret = rdp_init(dsp);
- if (ret) {
- DEBUG(0, ("Error re-initializing rdp cursors: %s\n",
- strerror(ret)));
- return;
- }
-
- DEBUG(9, ("Rewind DIR: %p, to resume_cookie: %#llx\n", dsp->dirp,
- dsp->resume_cookie));
-
- return;
-}
-
-/**
- * Close DIR pointer and remove all state for that directory open.
- *
- * @param[in] handle vfs handle given in most VFS calls
- * @param[in] dirp system DIR handle to set offset on
- *
- * @return -1 on failure, setting errno
- */
-int
-onefs_closedir(vfs_handle_struct *handle, SMB_STRUCT_DIR *dirp)
-{
- struct rdp_dir_state *dsp = NULL;
- bool same_as_last;
- int ret_val = -1;
- int ret = -1;
-
- /* Fallback to default system routines if readdirplus is disabled */
- if (!lp_parm_bool(SNUM(handle->conn), PARM_ONEFS_TYPE,
- PARM_USE_READDIRPLUS, PARM_USE_READDIRPLUS_DEFAULT))
- {
- return SMB_VFS_NEXT_CLOSEDIR(handle, dirp);
- }
-
- /* Retrieve state based off DIR handle */
- ret = rdp_retrieve_dir_state(dirp, &dsp, &same_as_last);
- if (ret) {
- DEBUG(1, ("Could not retrieve dir_state struct for "
- "SMB_STRUCT_DIR pointer.\n"));
- errno = ENOENT;
- return -1;
- }
-
- /* Close DIR pointer */
- ret_val = SMB_VFS_NEXT_CLOSEDIR(handle, dsp->dirp);
-
- DEBUG(9, ("Closed handle on DIR %p\n", dsp->dirp));
-
- /* Tear down state struct */
- DLIST_REMOVE(dirstatelist, dsp);
- SAFE_FREE(dsp);
-
- /* Set lastp to NULL, as cache is no longer valid */
- rdp_last_dirp = NULL;
-
- return ret_val;
-}
-
-/**
- * Initialize cache data at the beginning of every SMB search operation
- *
- * Since filesystem operations, such as delete files or meta data
- * updates can occur to files in the directory we're searching
- * between FIND_FIRST and FIND_NEXT calls we must refresh the cache
- * from the kernel on every new search SMB.
- *
- * @param[in] handle vfs handle given in most VFS calls
- * @param[in] dirp system DIR handle for the current search
- *
- * @return nothing
- */
-void
-onefs_init_search_op(vfs_handle_struct *handle, SMB_STRUCT_DIR *dirp)
-{
- /* Setting the rdp_last_dirp to NULL will cause the next readdir
- * operation to refill the cache. */
- rdp_last_dirp = NULL;
-
- return;
-}
git.samba.org / samba.git / blobdiff