diff options
Diffstat (limited to 'source3/modules/onefs_dir.c')
| -rw-r--r-- | source3/modules/onefs_dir.c | 622 |
1 files changed, 0 insertions, 622 deletions
diff --git a/source3/modules/onefs_dir.c b/source3/modules/onefs_dir.c deleted file mode 100644 index 1a0f4819fe..0000000000 --- a/source3/modules/onefs_dir.c +++ /dev/null @@ -1,622 +0,0 @@ -/* - * 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; - 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; - -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(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, 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 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 - */ -DIR * -onefs_opendir(vfs_handle_struct *handle, const char *fname, const char *mask, - uint32 attr) -{ - int ret = 0; - 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 - */ -struct dirent * -onefs_readdir(vfs_handle_struct *handle, DIR *dirp, - SMB_STRUCT_STAT *sbuf) -{ - struct rdp_dir_state *dsp = NULL; - 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 " - "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 += - ((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 = ((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, 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 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 " - "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, 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 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 " - "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, 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 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 " - "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, 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 " - "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, DIR *dirp) -{ - /* Setting the rdp_last_dirp to NULL will cause the next readdir - * operation to refill the cache. */ - rdp_last_dirp = NULL; - - return; -} |