extern int DEBUGLEVEL;
+static BOOL setup_write_cache(files_struct *, SMB_OFF_T);
/****************************************************************************
seek a file. Try to avoid the seek if possible
SMB_OFF_T seek_file(files_struct *fsp,SMB_OFF_T pos)
{
SMB_OFF_T offset = 0;
+ SMB_OFF_T seek_ret;
if (fsp->print_file && lp_postscript(fsp->conn->service))
offset = 3;
- fsp->pos = (sys_lseek(fsp->fd_ptr->fd,pos+offset,SEEK_SET) - offset);
+ seek_ret = sys_lseek(fsp->fd_ptr->fd,pos+offset,SEEK_SET);
+
+ /*
+ * We want to maintain the fiction that we can seek
+ * on a fifo for file system purposes. This allows
+ * people to set up UNIX fifo's that feed data to Windows
+ * applications. JRA.
+ */
+
+ if((seek_ret == -1) && (errno == ESPIPE)) {
+ seek_ret = pos+offset;
+ errno = 0;
+ }
+
+ if((seek_ret == -1) || (seek_ret != pos+offset)) {
+ DEBUG(0,("seek_file: sys_lseek failed. Error was %s\n", strerror(errno) ));
+ fsp->pos = -1;
+ return -1;
+ }
+
+ fsp->pos = seek_ret - offset;
DEBUG(10,("seek_file: requested pos = %.0f, new pos = %.0f\n",
(double)(pos+offset), (double)fsp->pos ));
return(fsp->pos);
}
+/****************************************************************************
+ Read from write cache if we can.
+****************************************************************************/
+
+static unsigned int cache_read_hits;
+
+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);
+
+ cache_read_hits++;
+
+ return True;
+}
+
/****************************************************************************
read from a file
****************************************************************************/
}
#endif
-#if WITH_MMAP
- if (fsp->mmap_ptr) {
- SMB_OFF_T num = (fsp->mmap_size > pos) ? (fsp->mmap_size - pos) : 0;
- num = MIN(n,num);
- if (num > 0) {
- memcpy(data,fsp->mmap_ptr+pos,num);
- data += num;
- pos += num;
- n -= num;
- ret += num;
- }
- }
-#endif
+ /*
+ * Serve from write cache if we can.
+ */
+ if(read_from_write_cache(fsp, data, pos, n))
+ return n;
- if (seek_file(fsp,pos) != pos) {
+ flush_write_cache(fsp, READ_FLUSH);
+
+ if (seek_file(fsp,pos) == -1) {
DEBUG(3,("read_file: Failed to seek to %.0f\n",(double)pos));
return(ret);
}
return(ret);
}
+/* Write cache static counters. */
+
+static unsigned int abutted_writes;
+static unsigned int total_writes;
+static unsigned int non_oplock_writes;
+static unsigned int direct_writes;
+static unsigned int init_writes;
+static unsigned int flushed_writes;
+static unsigned int num_perfect_writes;
+static unsigned int flush_reasons[NUM_FLUSH_REASONS];
+
+/* how many write cache buffers have been allocated */
+static unsigned int allocated_write_caches;
+static unsigned int num_write_caches;
+
+/****************************************************************************
+ *Really* write to a file
+****************************************************************************/
+
+static ssize_t real_write_file(files_struct *fsp,char *data,SMB_OFF_T pos, size_t n)
+{
+ if ((pos != -1) && (seek_file(fsp,pos) == -1))
+ return -1;
+
+ return write_data(fsp->fd_ptr->fd,data,n);
+}
/****************************************************************************
write to a file
****************************************************************************/
-ssize_t write_file(files_struct *fsp,char *data,size_t n)
+ssize_t write_file(files_struct *fsp, 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->can_write) {
errno = EPERM;
if (!fsp->modified) {
SMB_STRUCT_STAT st;
fsp->modified = True;
+
if (sys_fstat(fsp->fd_ptr->fd,&st) == 0) {
int dosmode = dos_mode(fsp->conn,fsp->fsp_name,&st);
if (MAP_ARCHIVE(fsp->conn) && !IS_DOS_ARCHIVE(dosmode)) {
file_chmod(fsp->conn,fsp->fsp_name,dosmode | aARCH,&st);
}
+
+ /*
+ * If this is the first write and we have an exclusive oplock then setup
+ * the write cache.
+ */
+
+ if ((fsp->oplock_type == EXCLUSIVE_OPLOCK) && !wcp) {
+ setup_write_cache(fsp, st.st_size);
+ wcp = fsp->wcp;
+ }
}
}
- return(write_data(fsp->fd_ptr->fd,data,n));
+ total_writes++;
+ if (!fsp->oplock_type) {
+ non_oplock_writes++;
+ }
+
+ /*
+ * 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.
+ */
+
+ if (LEVEL_II_OPLOCK_TYPE(fsp->oplock_type)) {
+ SMB_DEV_T dev = fsp->fd_ptr->dev;
+ SMB_INO_T inode = fsp->fd_ptr->inode;
+ share_mode_entry *share_list = NULL;
+ pid_t pid = getpid();
+ int token = -1;
+ int num_share_modes = 0;
+ int i;
+
+ if (lock_share_entry(fsp->conn, dev, inode, &token) == False) {
+ DEBUG(0,("write_file: failed to lock share mode entry for file %s.\n", fsp->fsp_name ));
+ }
+
+ num_share_modes = get_share_modes(fsp->conn, token, dev, inode, &share_list);
+
+ for(i = 0; i < num_share_modes; i++) {
+ share_mode_entry *share_entry = &share_list[i];
+
+ /*
+ * As there could have been multiple writes waiting at the lock_share_entry
+ * gate we may not be the first to enter. Hence the state of the op_types
+ * in the share mode entries may be partly NO_OPLOCK and partly LEVEL_II
+ * oplock. It will do no harm to re-send break messages to those smbd's
+ * that are still waiting their turn to remove their LEVEL_II state, and
+ * also no harm to ignore existing NO_OPLOCK states. JRA.
+ */
+
+ if (share_entry->op_type == NO_OPLOCK)
+ continue;
+
+ /* Paranoia .... */
+ if (EXCLUSIVE_OPLOCK_TYPE(share_entry->op_type)) {
+ DEBUG(0,("write_file: PANIC. share mode entry %d is an exlusive oplock !\n", i ));
+ abort();
+ }
+
+ /*
+ * Check if this is a file we have open (including the
+ * file we've been called to do write_file on. If so
+ * then break it directly without releasing the lock.
+ */
+
+ if (pid == share_entry->pid) {
+ files_struct *new_fsp = file_find_dit(dev, inode, &share_entry->time);
+
+ /* Paranoia check... */
+ if(new_fsp == NULL) {
+ DEBUG(0,("write_file: PANIC. share mode entry %d is not a local file !\n", i ));
+ abort();
+ }
+ oplock_break_level2(new_fsp, True, token);
+
+ } else {
+
+ /*
+ * This is a remote file and so we send an asynchronous
+ * message.
+ */
+
+ request_oplock_break(share_entry, dev, inode);
+ }
+ }
+
+ free((char *)share_list);
+ unlock_share_entry(fsp->conn, dev, inode, token);
+ }
+
+ /* Paranoia check... */
+ if (LEVEL_II_OPLOCK_TYPE(fsp->oplock_type)) {
+ DEBUG(0,("write_file: PANIC. File %s still has a level II oplock.\n", fsp->fsp_name));
+ abort();
+ }
+
+ if (total_writes % 500 == 0) {
+ DEBUG(3,("WRITECACHE: initwrites=%u abutted=%u flushes=%u total=%u \
+nonop=%u allocated=%u active=%u direct=%u perfect=%u readhits=%u\n",
+ init_writes, abutted_writes, flushed_writes, total_writes, non_oplock_writes,
+ allocated_write_caches,
+ num_write_caches, direct_writes, num_perfect_writes, cache_read_hits ));
+
+ DEBUG(3,("WRITECACHE: SEEK=%d, READ=%d, WRITE=%d, READRAW=%d, OPLOCK=%d, CLOSE=%d, SYNC=%d\n",
+ flush_reasons[SEEK_FLUSH],
+ flush_reasons[READ_FLUSH],
+ flush_reasons[WRITE_FLUSH],
+ flush_reasons[READRAW_FLUSH],
+ flush_reasons[OPLOCK_RELEASE_FLUSH],
+ flush_reasons[CLOSE_FLUSH],
+ flush_reasons[SYNC_FLUSH] ));
+ }
+
+ if(!wcp) {
+ direct_writes++;
+ return real_write_file(fsp, data, pos, n);
+ }
+
+ DEBUG(9,("write_file(fd=%d pos=%d size=%d) wofs=%d wsize=%d\n",
+ fsp->fd_ptr->fd, (int)pos, (int)n, (int)wcp->offset, (int)wcp->data_size));
+
+ /*
+ * 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)) {
+
+ /*
+ * 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;
+
+ /*
+ * 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;
+
+ 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)) {
+
+ /*
+ * 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;
+
+ /*
+ * 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;
+
+ abutted_writes++;
+ total_written = data_used;
+
+ write_path = 2;
+
+ } else if ( (pos >= wcp->file_size) &&
+ (pos > wcp->offset + wcp->data_size) &&
+ (pos < wcp->offset + wcp->alloc_size) ) {
+
+ /*
+ * Non-contiguous write part of which fits within
+ * the cache buffer and is extending 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 known file length.
+ */
+
+ wcp->file_size = wcp->offset + wcp->data_size;
+
+#if 0
+ if (set_filelen(fsp->fd_ptr->fd, wcp->file_size) == -1) {
+ DEBUG(0,("write_file: error %s in setting file to length %.0f\n",
+ strerror(errno), (double)wcp->file_size ));
+ return -1;
+ }
+#endif
+
+ /*
+ * 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;
+
+ abutted_writes++;
+ total_written = data_used;
+
+ write_path = 3;
+
+ } else {
+
+ /*
+ * 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->fd_ptr->fd, (double)pos, (unsigned int)n, (double)wcp->offset, (unsigned int)wcp->data_size ));
+
+ /*
+ * Update the file size if needed.
+ */
+
+ if(pos + n > wcp->file_size)
+ wcp->file_size = pos + n;
+
+ /*
+ * 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 {
+ direct_writes++;
+ return real_write_file(fsp, data, pos, n);
+ }
+
+ write_path = 4;
+
+ }
+
+ if(wcp->data_size > wcp->file_size)
+ wcp->file_size = wcp->data_size;
+
+ if (cache_flush_needed) {
+ flushed_writes++;
+
+ 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->fd_ptr->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 ) {
+ if(real_write_file(fsp, data, pos, n) == -1)
+ return -1;
+ direct_writes++;
+ return total_written + n;
+ }
+
+ /*
+ * If there's any data left, cache it.
+ */
+
+ if (n) {
+ if (wcp->data_size) {
+ abutted_writes++;
+ DEBUG(9,("abutted write (%u)\n", abutted_writes));
+ } else {
+ init_writes++;
+ }
+ memcpy(wcp->data+wcp->data_size, data, n);
+ if (wcp->data_size == 0) {
+ wcp->offset = pos;
+ num_write_caches++;
+ }
+ wcp->data_size += n;
+ DEBUG(9,("cache return %u\n", (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;
+
+ allocated_write_caches--;
+
+ SMB_ASSERT(wcp->data_size == 0);
+
+ free(wcp->data);
+ free(wcp);
+
+ fsp->wcp = NULL;
+}
+
+/****************************************************************************
+ 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 = (write_cache *)malloc(sizeof(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 = malloc(wcp->alloc_size)) == NULL) {
+ DEBUG(0,("setup_write_cache: malloc fail for buffer size %u.\n",
+ (unsigned int)wcp->alloc_size ));
+ free(wcp);
+ return False;
+ }
+
+ fsp->wcp = wcp;
+ allocated_write_caches++;
+
+ return True;
+}
+
+/****************************************************************************
+ Cope with a size change.
+****************************************************************************/
+
+void set_filelen_write_cache(files_struct *fsp, SMB_OFF_T file_size)
+{
+ if(fsp->wcp) {
+ flush_write_cache(fsp, SIZECHANGE_FLUSH);
+ 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;
+
+ if(!wcp || !wcp->data_size)
+ return 0;
+
+ data_size = wcp->data_size;
+ wcp->data_size = 0;
+
+ num_write_caches--;
+
+ flush_reasons[(int)reason]++;
+
+ DEBUG(9,("flushing write cache: fd = %d, off=%.0f, size=%u\n",
+ fsp->fd_ptr->fd, (double)wcp->offset, (unsigned int)data_size));
+
+ if(data_size == wcp->alloc_size)
+ num_perfect_writes++;
+
+ return real_write_file(fsp, wcp->data, wcp->offset, data_size);
+}
/*******************************************************************
sync a file
********************************************************************/
void sync_file(connection_struct *conn, files_struct *fsp)
{
#ifdef HAVE_FSYNC
- if(lp_strict_sync(SNUM(conn)))
+ if(lp_strict_sync(SNUM(conn)) && fsp->fd_ptr != NULL) {
+ flush_write_cache(fsp, SYNC_FLUSH);
fsync(fsp->fd_ptr->fd);
+ }
#endif
}
git.samba.org / samba.git / blobdiff