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-rw-r--r--source3/smbd/fileio.c955
1 files changed, 955 insertions, 0 deletions
diff --git a/source3/smbd/fileio.c b/source3/smbd/fileio.c
new file mode 100644
index 0000000000..60aeeef1e2
--- /dev/null
+++ b/source3/smbd/fileio.c
@@ -0,0 +1,955 @@
+/*
+ Unix SMB/Netbios implementation.
+ Version 1.9.
+ read/write to a files_struct
+ Copyright (C) Andrew Tridgell 1992-1998
+ Copyright (C) Jeremy Allison 2000-2002. - write cache.
+
+ 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"
+
+static bool setup_write_cache(files_struct *, SMB_OFF_T);
+
+/****************************************************************************
+ Read from write cache if we can.
+****************************************************************************/
+
+static bool read_from_write_cache(files_struct *fsp,char *data,SMB_OFF_T pos,size_t n)
+{
+ write_cache *wcp = fsp->wcp;
+
+ if(!wcp) {
+ return False;
+ }
+
+ if( n > wcp->data_size || pos < wcp->offset || pos + n > wcp->offset + wcp->data_size) {
+ return False;
+ }
+
+ memcpy(data, wcp->data + (pos - wcp->offset), n);
+
+ DO_PROFILE_INC(writecache_read_hits);
+
+ return True;
+}
+
+/****************************************************************************
+ Read from a file.
+****************************************************************************/
+
+ssize_t read_file(files_struct *fsp,char *data,SMB_OFF_T pos,size_t n)
+{
+ ssize_t ret=0,readret;
+
+ /* you can't read from print files */
+ if (fsp->print_file) {
+ return -1;
+ }
+
+ /*
+ * Serve from write cache if we can.
+ */
+
+ if(read_from_write_cache(fsp, data, pos, n)) {
+ fsp->fh->pos = pos + n;
+ fsp->fh->position_information = fsp->fh->pos;
+ return n;
+ }
+
+ flush_write_cache(fsp, READ_FLUSH);
+
+ fsp->fh->pos = pos;
+
+ if (n > 0) {
+#ifdef DMF_FIX
+ int numretries = 3;
+tryagain:
+ readret = SMB_VFS_PREAD(fsp,data,n,pos);
+
+ if (readret == -1) {
+ if ((errno == EAGAIN) && numretries) {
+ DEBUG(3,("read_file EAGAIN retry in 10 seconds\n"));
+ (void)sleep(10);
+ --numretries;
+ goto tryagain;
+ }
+ return -1;
+ }
+#else /* NO DMF fix. */
+ readret = SMB_VFS_PREAD(fsp,data,n,pos);
+
+ if (readret == -1) {
+ return -1;
+ }
+#endif
+ if (readret > 0) {
+ ret += readret;
+ }
+ }
+
+ DEBUG(10,("read_file (%s): pos = %.0f, size = %lu, returned %lu\n",
+ fsp->fsp_name, (double)pos, (unsigned long)n, (long)ret ));
+
+ fsp->fh->pos += ret;
+ fsp->fh->position_information = fsp->fh->pos;
+
+ return(ret);
+}
+
+/* how many write cache buffers have been allocated */
+static unsigned int allocated_write_caches;
+
+/****************************************************************************
+ *Really* write to a file.
+****************************************************************************/
+
+static ssize_t real_write_file(struct smb_request *req,
+ files_struct *fsp,
+ const char *data,
+ SMB_OFF_T pos,
+ size_t n)
+{
+ ssize_t ret;
+
+ if (pos == -1) {
+ ret = vfs_write_data(req, fsp, data, n);
+ } else {
+ fsp->fh->pos = pos;
+ if (pos && lp_strict_allocate(SNUM(fsp->conn))) {
+ if (vfs_fill_sparse(fsp, pos) == -1) {
+ return -1;
+ }
+ }
+ ret = vfs_pwrite_data(req, fsp, data, n, pos);
+ }
+
+ DEBUG(10,("real_write_file (%s): pos = %.0f, size = %lu, returned %ld\n",
+ fsp->fsp_name, (double)pos, (unsigned long)n, (long)ret ));
+
+ if (ret != -1) {
+ fsp->fh->pos += ret;
+
+/* Yes - this is correct - writes don't update this. JRA. */
+/* Found by Samba4 tests. */
+#if 0
+ fsp->position_information = fsp->pos;
+#endif
+ }
+
+ return ret;
+}
+
+/****************************************************************************
+ File size cache change.
+ Updates size on disk but doesn't flush the cache.
+****************************************************************************/
+
+static int wcp_file_size_change(files_struct *fsp)
+{
+ int ret;
+ write_cache *wcp = fsp->wcp;
+
+ wcp->file_size = wcp->offset + wcp->data_size;
+ ret = SMB_VFS_FTRUNCATE(fsp, wcp->file_size);
+ if (ret == -1) {
+ DEBUG(0,("wcp_file_size_change (%s): ftruncate of size %.0f error %s\n",
+ fsp->fsp_name, (double)wcp->file_size, strerror(errno) ));
+ }
+ return ret;
+}
+
+static void update_write_time_handler(struct event_context *ctx,
+ struct timed_event *te,
+ const struct timeval *now,
+ void *private_data)
+{
+ files_struct *fsp = (files_struct *)private_data;
+
+ /* Remove the timed event handler. */
+ TALLOC_FREE(fsp->update_write_time_event);
+ DEBUG(5, ("Update write time on %s\n", fsp->fsp_name));
+
+ /* change the write time if not already changed by someone else */
+ update_write_time(fsp);
+}
+
+/*********************************************************
+ Schedule a write time update for WRITE_TIME_UPDATE_USEC_DELAY
+ in the future.
+*********************************************************/
+
+void trigger_write_time_update(struct files_struct *fsp)
+{
+ int delay;
+
+ if (fsp->write_time_forced) {
+ /* No point - "sticky" write times
+ * in effect.
+ */
+ return;
+ }
+
+ if (fsp->update_write_time_triggered) {
+ /*
+ * We only update the write time
+ * on the first write. After that
+ * no other writes affect this.
+ */
+ return;
+ }
+ fsp->update_write_time_triggered = true;
+
+ delay = lp_parm_int(SNUM(fsp->conn),
+ "smbd", "writetimeupdatedelay",
+ WRITE_TIME_UPDATE_USEC_DELAY);
+
+ /* trigger the update 2 seconds later */
+ fsp->update_write_time_on_close = true;
+ fsp->update_write_time_event =
+ event_add_timed(smbd_event_context(), NULL,
+ timeval_current_ofs(0, delay),
+ "update_write_time_handler",
+ update_write_time_handler, fsp);
+}
+
+void trigger_write_time_update_immediate(struct files_struct *fsp)
+{
+ if (fsp->write_time_forced) {
+ /*
+ * No point - "sticky" write times
+ * in effect.
+ */
+ return;
+ }
+
+ TALLOC_FREE(fsp->update_write_time_event);
+ DEBUG(5, ("Update write time immediate on %s\n", fsp->fsp_name));
+
+ fsp->update_write_time_triggered = true;
+
+ fsp->update_write_time_on_close = false;
+ update_write_time(fsp);
+}
+
+/****************************************************************************
+ Write to a file.
+****************************************************************************/
+
+ssize_t write_file(struct smb_request *req,
+ files_struct *fsp,
+ const char *data,
+ SMB_OFF_T pos,
+ size_t n)
+{
+ write_cache *wcp = fsp->wcp;
+ ssize_t total_written = 0;
+ int write_path = -1;
+
+ if (fsp->print_file) {
+ fstring sharename;
+ uint32 jobid;
+
+ if (!rap_to_pjobid(fsp->rap_print_jobid, sharename, &jobid)) {
+ DEBUG(3,("write_file: Unable to map RAP jobid %u to jobid.\n",
+ (unsigned int)fsp->rap_print_jobid ));
+ errno = EBADF;
+ return -1;
+ }
+
+ return print_job_write(SNUM(fsp->conn), jobid, data, pos, n);
+ }
+
+ if (!fsp->can_write) {
+ errno = EPERM;
+ return -1;
+ }
+
+ if (!fsp->modified) {
+ SMB_STRUCT_STAT st;
+ fsp->modified = True;
+
+ if (SMB_VFS_FSTAT(fsp, &st) == 0) {
+ int dosmode;
+ trigger_write_time_update(fsp);
+ dosmode = dos_mode(fsp->conn,fsp->fsp_name,&st);
+ if ((lp_store_dos_attributes(SNUM(fsp->conn)) ||
+ MAP_ARCHIVE(fsp->conn)) &&
+ !IS_DOS_ARCHIVE(dosmode)) {
+ file_set_dosmode(fsp->conn,fsp->fsp_name,
+ dosmode | aARCH,&st,
+ NULL,
+ false);
+ }
+
+ /*
+ * If this is the first write and we have an exclusive oplock then setup
+ * the write cache.
+ */
+
+ if (EXCLUSIVE_OPLOCK_TYPE(fsp->oplock_type) && !wcp) {
+ setup_write_cache(fsp, st.st_size);
+ wcp = fsp->wcp;
+ }
+ }
+ }
+
+#ifdef WITH_PROFILE
+ DO_PROFILE_INC(writecache_total_writes);
+ if (!fsp->oplock_type) {
+ DO_PROFILE_INC(writecache_non_oplock_writes);
+ }
+#endif
+
+ /*
+ * If this file is level II oplocked then we need
+ * to grab the shared memory lock and inform all
+ * other files with a level II lock that they need
+ * to flush their read caches. We keep the lock over
+ * the shared memory area whilst doing this.
+ */
+
+ release_level_2_oplocks_on_change(fsp);
+
+#ifdef WITH_PROFILE
+ if (profile_p && profile_p->writecache_total_writes % 500 == 0) {
+ DEBUG(3,("WRITECACHE: initwrites=%u abutted=%u total=%u \
+nonop=%u allocated=%u active=%u direct=%u perfect=%u readhits=%u\n",
+ profile_p->writecache_init_writes,
+ profile_p->writecache_abutted_writes,
+ profile_p->writecache_total_writes,
+ profile_p->writecache_non_oplock_writes,
+ profile_p->writecache_allocated_write_caches,
+ profile_p->writecache_num_write_caches,
+ profile_p->writecache_direct_writes,
+ profile_p->writecache_num_perfect_writes,
+ profile_p->writecache_read_hits ));
+
+ DEBUG(3,("WRITECACHE: Flushes SEEK=%d, READ=%d, WRITE=%d, READRAW=%d, OPLOCK=%d, CLOSE=%d, SYNC=%d\n",
+ profile_p->writecache_flushed_writes[SEEK_FLUSH],
+ profile_p->writecache_flushed_writes[READ_FLUSH],
+ profile_p->writecache_flushed_writes[WRITE_FLUSH],
+ profile_p->writecache_flushed_writes[READRAW_FLUSH],
+ profile_p->writecache_flushed_writes[OPLOCK_RELEASE_FLUSH],
+ profile_p->writecache_flushed_writes[CLOSE_FLUSH],
+ profile_p->writecache_flushed_writes[SYNC_FLUSH] ));
+ }
+#endif
+
+ if (wcp && req->unread_bytes) {
+ /* If we're using receivefile don't
+ * deal with a write cache.
+ */
+ flush_write_cache(fsp, WRITE_FLUSH);
+ delete_write_cache(fsp);
+ wcp = NULL;
+ }
+
+ if(!wcp) {
+ DO_PROFILE_INC(writecache_direct_writes);
+ total_written = real_write_file(req, fsp, data, pos, n);
+ return total_written;
+ }
+
+ DEBUG(9,("write_file (%s)(fd=%d pos=%.0f size=%u) wcp->offset=%.0f wcp->data_size=%u\n",
+ fsp->fsp_name, fsp->fh->fd, (double)pos, (unsigned int)n, (double)wcp->offset, (unsigned int)wcp->data_size));
+
+ fsp->fh->pos = pos + n;
+
+ /*
+ * If we have active cache and it isn't contiguous then we flush.
+ * NOTE: There is a small problem with running out of disk ....
+ */
+
+ if (wcp->data_size) {
+ bool cache_flush_needed = False;
+
+ if ((pos >= wcp->offset) && (pos <= wcp->offset + wcp->data_size)) {
+
+ /* ASCII art.... JRA.
+
+ +--------------+-----
+ | Cached data | Rest of allocated cache buffer....
+ +--------------+-----
+
+ +-------------------+
+ | Data to write |
+ +-------------------+
+
+ */
+
+ /*
+ * Start of write overlaps or abutts the existing data.
+ */
+
+ size_t data_used = MIN((wcp->alloc_size - (pos - wcp->offset)), n);
+
+ memcpy(wcp->data + (pos - wcp->offset), data, data_used);
+
+ /*
+ * Update the current buffer size with the new data.
+ */
+
+ if(pos + data_used > wcp->offset + wcp->data_size) {
+ wcp->data_size = pos + data_used - wcp->offset;
+ }
+
+ /*
+ * Update the file size if changed.
+ */
+
+ if (wcp->offset + wcp->data_size > wcp->file_size) {
+ if (wcp_file_size_change(fsp) == -1) {
+ return -1;
+ }
+ }
+
+ /*
+ * If we used all the data then
+ * return here.
+ */
+
+ if(n == data_used) {
+ return n;
+ } else {
+ cache_flush_needed = True;
+ }
+ /*
+ * Move the start of data forward by the amount used,
+ * cut down the amount left by the same amount.
+ */
+
+ data += data_used;
+ pos += data_used;
+ n -= data_used;
+
+ DO_PROFILE_INC(writecache_abutted_writes);
+ total_written = data_used;
+
+ write_path = 1;
+
+ } else if ((pos < wcp->offset) && (pos + n > wcp->offset) &&
+ (pos + n <= wcp->offset + wcp->alloc_size)) {
+
+ /* ASCII art.... JRA.
+
+ +---------------+
+ | Cache buffer |
+ +---------------+
+
+ +-------------------+
+ | Data to write |
+ +-------------------+
+
+ */
+
+ /*
+ * End of write overlaps the existing data.
+ */
+
+ size_t data_used = pos + n - wcp->offset;
+
+ memcpy(wcp->data, data + n - data_used, data_used);
+
+ /*
+ * Update the current buffer size with the new data.
+ */
+
+ if(pos + n > wcp->offset + wcp->data_size) {
+ wcp->data_size = pos + n - wcp->offset;
+ }
+
+ /*
+ * Update the file size if changed.
+ */
+
+ if (wcp->offset + wcp->data_size > wcp->file_size) {
+ if (wcp_file_size_change(fsp) == -1) {
+ return -1;
+ }
+ }
+
+ /*
+ * We don't need to move the start of data, but we
+ * cut down the amount left by the amount used.
+ */
+
+ n -= data_used;
+
+ /*
+ * We cannot have used all the data here.
+ */
+
+ cache_flush_needed = True;
+
+ DO_PROFILE_INC(writecache_abutted_writes);
+ total_written = data_used;
+
+ write_path = 2;
+
+ } else if ( (pos >= wcp->file_size) &&
+ (wcp->offset + wcp->data_size == wcp->file_size) &&
+ (pos > wcp->offset + wcp->data_size) &&
+ (pos < wcp->offset + wcp->alloc_size) ) {
+
+ /* ASCII art.... JRA.
+
+ End of file ---->|
+
+ +---------------+---------------+
+ | Cached data | Cache buffer |
+ +---------------+---------------+
+
+ +-------------------+
+ | Data to write |
+ +-------------------+
+
+ */
+
+ /*
+ * Non-contiguous write part of which fits within
+ * the cache buffer and is extending the file
+ * and the cache contents reflect the current
+ * data up to the current end of the file.
+ */
+
+ size_t data_used;
+
+ if(pos + n <= wcp->offset + wcp->alloc_size) {
+ data_used = n;
+ } else {
+ data_used = wcp->offset + wcp->alloc_size - pos;
+ }
+
+ /*
+ * Fill in the non-continuous area with zeros.
+ */
+
+ memset(wcp->data + wcp->data_size, '\0',
+ pos - (wcp->offset + wcp->data_size) );
+
+ memcpy(wcp->data + (pos - wcp->offset), data, data_used);
+
+ /*
+ * Update the current buffer size with the new data.
+ */
+
+ if(pos + data_used > wcp->offset + wcp->data_size) {
+ wcp->data_size = pos + data_used - wcp->offset;
+ }
+
+ /*
+ * Update the file size if changed.
+ */
+
+ if (wcp->offset + wcp->data_size > wcp->file_size) {
+ if (wcp_file_size_change(fsp) == -1) {
+ return -1;
+ }
+ }
+
+ /*
+ * If we used all the data then
+ * return here.
+ */
+
+ if(n == data_used) {
+ return n;
+ } else {
+ cache_flush_needed = True;
+ }
+
+ /*
+ * Move the start of data forward by the amount used,
+ * cut down the amount left by the same amount.
+ */
+
+ data += data_used;
+ pos += data_used;
+ n -= data_used;
+
+ DO_PROFILE_INC(writecache_abutted_writes);
+ total_written = data_used;
+
+ write_path = 3;
+
+ } else if ( (pos >= wcp->file_size) &&
+ (n == 1) &&
+ (wcp->file_size == wcp->offset + wcp->data_size) &&
+ (pos < wcp->file_size + wcp->alloc_size)) {
+
+ /*
+
+ End of file ---->|
+
+ +---------------+---------------+
+ | Cached data | Cache buffer |
+ +---------------+---------------+
+
+ |<------- allocated size ---------------->|
+
+ +--------+
+ | 1 Byte |
+ +--------+
+
+ MS-Office seems to do this a lot to determine if there's enough
+ space on the filesystem to write a new file.
+
+ Change to :
+
+ End of file ---->|
+ +-----------------------+--------+
+ | Zeroed Cached data | 1 Byte |
+ +-----------------------+--------+
+ */
+
+ flush_write_cache(fsp, WRITE_FLUSH);
+ wcp->offset = wcp->file_size;
+ wcp->data_size = pos - wcp->file_size + 1;
+ memset(wcp->data, '\0', wcp->data_size);
+ memcpy(wcp->data + wcp->data_size-1, data, 1);
+
+ /*
+ * Update the file size if changed.
+ */
+
+ if (wcp->offset + wcp->data_size > wcp->file_size) {
+ if (wcp_file_size_change(fsp) == -1) {
+ return -1;
+ }
+ }
+
+ return n;
+
+ } else {
+
+ /* ASCII art..... JRA.
+
+ Case 1).
+
+ +---------------+---------------+
+ | Cached data | Cache buffer |
+ +---------------+---------------+
+
+ +-------------------+
+ | Data to write |
+ +-------------------+
+
+ Case 2).
+
+ +---------------+---------------+
+ | Cached data | Cache buffer |
+ +---------------+---------------+
+
+ +-------------------+
+ | Data to write |
+ +-------------------+
+
+ Case 3).
+
+ +---------------+---------------+
+ | Cached data | Cache buffer |
+ +---------------+---------------+
+
+ +-----------------------------------------------------+
+ | Data to write |
+ +-----------------------------------------------------+
+
+ */
+
+ /*
+ * Write is bigger than buffer, or there is no overlap on the
+ * low or high ends.
+ */
+
+ DEBUG(9,("write_file: non cacheable write : fd = %d, pos = %.0f, len = %u, current cache pos = %.0f \
+len = %u\n",fsp->fh->fd, (double)pos, (unsigned int)n, (double)wcp->offset, (unsigned int)wcp->data_size ));
+
+ /*
+ * If write would fit in the cache, and is larger than
+ * the data already in the cache, flush the cache and
+ * preferentially copy the data new data into it. Otherwise
+ * just write the data directly.
+ */
+
+ if ( n <= wcp->alloc_size && n > wcp->data_size) {
+ cache_flush_needed = True;
+ } else {
+ ssize_t ret = real_write_file(NULL,fsp, data, pos, n);
+
+ /*
+ * If the write overlaps the entire cache, then
+ * discard the current contents of the cache.
+ * Fix from Rasmus Borup Hansen rbh@math.ku.dk.
+ */
+
+ if ((pos <= wcp->offset) &&
+ (pos + n >= wcp->offset + wcp->data_size) ) {
+ DEBUG(9,("write_file: discarding overwritten write \
+cache: fd = %d, off=%.0f, size=%u\n", fsp->fh->fd, (double)wcp->offset, (unsigned int)wcp->data_size ));
+ wcp->data_size = 0;
+ }
+
+ DO_PROFILE_INC(writecache_direct_writes);
+ if (ret == -1) {
+ return ret;
+ }
+
+ if (pos + ret > wcp->file_size) {
+ wcp->file_size = pos + ret;
+ }
+
+ return ret;
+ }
+
+ write_path = 4;
+
+ }
+
+ if (cache_flush_needed) {
+ DEBUG(3,("WRITE_FLUSH:%d: due to noncontinuous write: fd = %d, size = %.0f, pos = %.0f, \
+n = %u, wcp->offset=%.0f, wcp->data_size=%u\n",
+ write_path, fsp->fh->fd, (double)wcp->file_size, (double)pos, (unsigned int)n,
+ (double)wcp->offset, (unsigned int)wcp->data_size ));
+
+ flush_write_cache(fsp, WRITE_FLUSH);
+ }
+ }
+
+ /*
+ * If the write request is bigger than the cache
+ * size, write it all out.
+ */
+
+ if (n > wcp->alloc_size ) {
+ ssize_t ret = real_write_file(NULL,fsp, data, pos, n);
+ if (ret == -1) {
+ return -1;
+ }
+
+ if (pos + ret > wcp->file_size) {
+ wcp->file_size = pos + n;
+ }
+
+ DO_PROFILE_INC(writecache_direct_writes);
+ return total_written + n;
+ }
+
+ /*
+ * If there's any data left, cache it.
+ */
+
+ if (n) {
+#ifdef WITH_PROFILE
+ if (wcp->data_size) {
+ DO_PROFILE_INC(writecache_abutted_writes);
+ } else {
+ DO_PROFILE_INC(writecache_init_writes);
+ }
+#endif
+ memcpy(wcp->data+wcp->data_size, data, n);
+ if (wcp->data_size == 0) {
+ wcp->offset = pos;
+ DO_PROFILE_INC(writecache_num_write_caches);
+ }
+ wcp->data_size += n;
+
+ /*
+ * Update the file size if changed.
+ */
+
+ if (wcp->offset + wcp->data_size > wcp->file_size) {
+ if (wcp_file_size_change(fsp) == -1) {
+ return -1;
+ }
+ }
+ DEBUG(9,("wcp->offset = %.0f wcp->data_size = %u cache return %u\n",
+ (double)wcp->offset, (unsigned int)wcp->data_size, (unsigned int)n));
+
+ total_written += n;
+ return total_written; /* .... that's a write :) */
+ }
+
+ return total_written;
+}
+
+/****************************************************************************
+ Delete the write cache structure.
+****************************************************************************/
+
+void delete_write_cache(files_struct *fsp)
+{
+ write_cache *wcp;
+
+ if(!fsp) {
+ return;
+ }
+
+ if(!(wcp = fsp->wcp)) {
+ return;
+ }
+
+ DO_PROFILE_DEC(writecache_allocated_write_caches);
+ allocated_write_caches--;
+
+ SMB_ASSERT(wcp->data_size == 0);
+
+ SAFE_FREE(wcp->data);
+ SAFE_FREE(fsp->wcp);
+
+ DEBUG(10,("delete_write_cache: File %s deleted write cache\n", fsp->fsp_name ));
+}
+
+/****************************************************************************
+ Setup the write cache structure.
+****************************************************************************/
+
+static bool setup_write_cache(files_struct *fsp, SMB_OFF_T file_size)
+{
+ ssize_t alloc_size = lp_write_cache_size(SNUM(fsp->conn));
+ write_cache *wcp;
+
+ if (allocated_write_caches >= MAX_WRITE_CACHES) {
+ return False;
+ }
+
+ if(alloc_size == 0 || fsp->wcp) {
+ return False;
+ }
+
+ if((wcp = SMB_MALLOC_P(write_cache)) == NULL) {
+ DEBUG(0,("setup_write_cache: malloc fail.\n"));
+ return False;
+ }
+
+ wcp->file_size = file_size;
+ wcp->offset = 0;
+ wcp->alloc_size = alloc_size;
+ wcp->data_size = 0;
+ if((wcp->data = (char *)SMB_MALLOC(wcp->alloc_size)) == NULL) {
+ DEBUG(0,("setup_write_cache: malloc fail for buffer size %u.\n",
+ (unsigned int)wcp->alloc_size ));
+ SAFE_FREE(wcp);
+ return False;
+ }
+
+ memset(wcp->data, '\0', wcp->alloc_size );
+
+ fsp->wcp = wcp;
+ DO_PROFILE_INC(writecache_allocated_write_caches);
+ allocated_write_caches++;
+
+ DEBUG(10,("setup_write_cache: File %s allocated write cache size %lu\n",
+ fsp->fsp_name, (unsigned long)wcp->alloc_size ));
+
+ return True;
+}
+
+/****************************************************************************
+ Cope with a size change.
+****************************************************************************/
+
+void set_filelen_write_cache(files_struct *fsp, SMB_OFF_T file_size)
+{
+ if(fsp->wcp) {
+ /* The cache *must* have been flushed before we do this. */
+ if (fsp->wcp->data_size != 0) {
+ char *msg;
+ asprintf(&msg, "set_filelen_write_cache: size change "
+ "on file %s with write cache size = %lu\n",
+ fsp->fsp_name,
+ (unsigned long)fsp->wcp->data_size);
+ smb_panic(msg);
+ }
+ fsp->wcp->file_size = file_size;
+ }
+}
+
+/*******************************************************************
+ Flush a write cache struct to disk.
+********************************************************************/
+
+ssize_t flush_write_cache(files_struct *fsp, enum flush_reason_enum reason)
+{
+ write_cache *wcp = fsp->wcp;
+ size_t data_size;
+ ssize_t ret;
+
+ if(!wcp || !wcp->data_size) {
+ return 0;
+ }
+
+ data_size = wcp->data_size;
+ wcp->data_size = 0;
+
+ DO_PROFILE_DEC_INC(writecache_num_write_caches,writecache_flushed_writes[reason]);
+
+ DEBUG(9,("flushing write cache: fd = %d, off=%.0f, size=%u\n",
+ fsp->fh->fd, (double)wcp->offset, (unsigned int)data_size));
+
+#ifdef WITH_PROFILE
+ if(data_size == wcp->alloc_size) {
+ DO_PROFILE_INC(writecache_num_perfect_writes);
+ }
+#endif
+
+ ret = real_write_file(NULL, fsp, wcp->data, wcp->offset, data_size);
+
+ /*
+ * Ensure file size if kept up to date if write extends file.
+ */
+
+ if ((ret != -1) && (wcp->offset + ret > wcp->file_size)) {
+ wcp->file_size = wcp->offset + ret;
+ }
+
+ return ret;
+}
+
+/*******************************************************************
+sync a file
+********************************************************************/
+
+NTSTATUS sync_file(connection_struct *conn, files_struct *fsp, bool write_through)
+{
+ if (fsp->fh->fd == -1)
+ return NT_STATUS_INVALID_HANDLE;
+
+ if (lp_strict_sync(SNUM(conn)) &&
+ (lp_syncalways(SNUM(conn)) || write_through)) {
+ int ret = flush_write_cache(fsp, SYNC_FLUSH);
+ if (ret == -1) {
+ return map_nt_error_from_unix(errno);
+ }
+ ret = SMB_VFS_FSYNC(fsp);
+ if (ret == -1) {
+ return map_nt_error_from_unix(errno);
+ }
+ }
+ return NT_STATUS_OK;
+}
+
+/************************************************************
+ Perform a stat whether a valid fd or not.
+************************************************************/
+
+int fsp_stat(files_struct *fsp, SMB_STRUCT_STAT *pst)
+{
+ if (fsp->fh->fd == -1) {
+ return SMB_VFS_STAT(fsp->conn, fsp->fsp_name, pst);
+ } else {
+ return SMB_VFS_FSTAT(fsp, pst);
+ }
+}