/*
- Copyright (C) Andrew Tridgell 1998
- Copyright (C) 2002 by Martin Pool
+ * File IO utilities used in rsync.
+ *
+ * Copyright (C) 1998 Andrew Tridgell
+ * Copyright (C) 2002 Martin Pool
+ * Copyright (C) 2004-2020 Wayne Davison
+ *
+ * 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, visit the http://fsf.org website.
+ */
- 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 2 of the License, or
- (at your option) any later version.
+#include "rsync.h"
+#include "inums.h"
- 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.
+#ifndef ENODATA
+#define ENODATA EAGAIN
+#endif
- You should have received a copy of the GNU General Public License
- along with this program; if not, write to the Free Software
- Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
-*/
-
-/*
- File IO utilities used in rsync
- */
-#include "rsync.h"
+/* We want all reads to be aligned on 1K boundaries. */
+#define ALIGN_BOUNDARY 1024
+/* How far past the boundary is an offset? */
+#define ALIGNED_OVERSHOOT(oft) ((oft) & (ALIGN_BOUNDARY-1))
+/* Round up a length to the next boundary */
+#define ALIGNED_LENGTH(len) ((((len) - 1) | (ALIGN_BOUNDARY-1)) + 1)
extern int sparse_files;
-static char last_byte;
-static int last_sparse;
+OFF_T preallocated_len = 0;
+
+static OFF_T sparse_seek = 0;
+static OFF_T sparse_past_write = 0;
-int sparse_end(int f)
+int sparse_end(int f, OFF_T size)
{
- if (last_sparse) {
- do_lseek(f,-1,SEEK_CUR);
- return (write(f,&last_byte,1) == 1 ? 0 : -1);
+ int ret;
+
+ sparse_past_write = 0;
+
+ if (!sparse_seek)
+ return 0;
+
+#ifdef HAVE_FTRUNCATE
+ ret = do_ftruncate(f, size);
+#else
+ if (do_lseek(f, sparse_seek-1, SEEK_CUR) != size-1)
+ ret = -1;
+ else {
+ do {
+ ret = write(f, "", 1);
+ } while (ret < 0 && errno == EINTR);
+
+ ret = ret <= 0 ? -1 : 0;
}
- last_sparse = 0;
- return 0;
-}
+#endif
+ sparse_seek = 0;
-static int write_sparse(int f,char *buf,size_t len)
+ return ret;
+}
+
+/* Note that the offset is just the caller letting us know where
+ * the current file position is in the file. The use_seek arg tells
+ * us that we should seek over matching data instead of writing it. */
+static int write_sparse(int f, int use_seek, OFF_T offset, const char *buf, int len)
{
- size_t l1=0, l2=0;
+ int l1 = 0, l2 = 0;
int ret;
for (l1 = 0; l1 < len && buf[l1] == 0; l1++) {}
for (l2 = 0; l2 < len-l1 && buf[len-(l2+1)] == 0; l2++) {}
- last_byte = buf[len-1];
+ sparse_seek += l1;
- if (l1 == len || l2 > 0)
- last_sparse=1;
+ if (l1 == len)
+ return len;
- if (l1 > 0) {
- do_lseek(f,l1,SEEK_CUR);
+ if (sparse_seek) {
+ if (sparse_past_write >= preallocated_len) {
+ if (do_lseek(f, sparse_seek, SEEK_CUR) < 0)
+ return -1;
+ } else if (do_punch_hole(f, sparse_past_write, sparse_seek) < 0) {
+ sparse_seek = 0;
+ return -1;
+ }
}
+ sparse_seek = l2;
+ sparse_past_write = offset + len - l2;
- if (l1 == len)
+ if (use_seek) {
+ /* The in-place data already matches. */
+ if (do_lseek(f, len - (l1+l2), SEEK_CUR) < 0)
+ return -1;
return len;
+ }
- ret = write(f, buf + l1, len - (l1+l2));
- if (ret == -1 || ret == 0)
+ while ((ret = write(f, buf + l1, len - (l1+l2))) <= 0) {
+ if (ret < 0 && errno == EINTR)
+ continue;
+ sparse_seek = 0;
return ret;
- else if (ret != (int) (len - (l1+l2)))
- return (l1+ret);
+ }
- if (l2 > 0)
- do_lseek(f,l2,SEEK_CUR);
+ if (ret != (int)(len - (l1+l2))) {
+ sparse_seek = 0;
+ return l1+ret;
+ }
return len;
}
-
static char *wf_writeBuf;
static size_t wf_writeBufSize;
static size_t wf_writeBufCnt;
return ret;
}
-
-/*
- * write_file does not allow incomplete writes. It loops internally
- * until len bytes are written or errno is set.
- */
-int write_file(int f,char *buf,size_t len)
+/* write_file does not allow incomplete writes. It loops internally
+ * until len bytes are written or errno is set. Note that use_seek and
+ * offset are only used in sparse processing (see write_sparse()). */
+int write_file(int f, int use_seek, OFF_T offset, const char *buf, int len)
{
int ret = 0;
while (len > 0) {
int r1;
- if (sparse_files) {
+ if (sparse_files > 0) {
int len1 = MIN(len, SPARSE_WRITE_SIZE);
- r1 = write_sparse(f, buf, len1);
+ r1 = write_sparse(f, use_seek, offset, buf, len1);
+ offset += r1;
} else {
if (!wf_writeBuf) {
wf_writeBufSize = WRITE_SIZE * 8;
wf_writeBufCnt = 0;
wf_writeBuf = new_array(char, wf_writeBufSize);
- if (!wf_writeBuf)
- out_of_memory("write_file");
}
- r1 = MIN(len, wf_writeBufSize - wf_writeBufCnt);
+ r1 = (int)MIN((size_t)len, wf_writeBufSize - wf_writeBufCnt);
if (r1) {
memcpy(wf_writeBuf + wf_writeBufCnt, buf, r1);
wf_writeBufCnt += r1;
return ret;
}
+/* An in-place update found identical data at an identical location. We either
+ * just seek past it, or (for an in-place sparse update), we give the data to
+ * the sparse processor with the use_seek flag set. */
+int skip_matched(int fd, OFF_T offset, const char *buf, int len)
+{
+ OFF_T pos;
+
+ if (sparse_files > 0) {
+ if (write_file(fd, 1, offset, buf, len) != len)
+ return -1;
+ return 0;
+ }
+
+ if (flush_write_file(fd) < 0)
+ return -1;
+
+ if ((pos = do_lseek(fd, len, SEEK_CUR)) != offset + len) {
+ rsyserr(FERROR_XFER, errno, "lseek returned %s, not %s",
+ big_num(pos), big_num(offset));
+ return -1;
+ }
+
+ return 0;
+}
/* This provides functionality somewhat similar to mmap() but using read().
* It gives sliding window access to a file. mmap() is not used because of
* the possibility of another program (such as a mailer) truncating the
* file thus giving us a SIGBUS. */
-struct map_struct *map_file(int fd, OFF_T len, OFF_T map_size,
- size_t block_size)
+struct map_struct *map_file(int fd, OFF_T len, int32 read_size, int32 blk_size)
{
struct map_struct *map;
- if (!(map = new(struct map_struct)))
- out_of_memory("map_file");
+ map = new0(struct map_struct);
- if (block_size && (map_size % block_size))
- map_size += block_size - (map_size % block_size);
+ if (blk_size && (read_size % blk_size))
+ read_size += blk_size - (read_size % blk_size);
- memset(map, 0, sizeof map[0]);
map->fd = fd;
map->file_size = len;
- map->def_window_size = map_size;
+ map->def_window_size = ALIGNED_LENGTH(read_size);
return map;
}
/* slide the read window in the file */
-char *map_ptr(struct map_struct *map,OFF_T offset,int len)
+char *map_ptr(struct map_struct *map, OFF_T offset, int32 len)
{
- int nread;
OFF_T window_start, read_start;
- int window_size, read_size, read_offset;
+ int32 window_size, read_size, read_offset, align_fudge;
if (len == 0)
return NULL;
-
- /* can't go beyond the end of file */
- if (len > (map->file_size - offset)) {
- len = map->file_size - offset;
+ if (len < 0) {
+ rprintf(FERROR, "invalid len passed to map_ptr: %ld\n",
+ (long)len);
+ exit_cleanup(RERR_FILEIO);
}
/* in most cases the region will already be available */
- if (offset >= map->p_offset &&
- offset+len <= map->p_offset+map->p_len) {
- return (map->p + (offset - map->p_offset));
- }
+ if (offset >= map->p_offset && offset+len <= map->p_offset+map->p_len)
+ return map->p + (offset - map->p_offset);
/* nope, we are going to have to do a read. Work out our desired window */
- window_start = offset;
+ align_fudge = (int32)ALIGNED_OVERSHOOT(offset);
+ window_start = offset - align_fudge;
window_size = map->def_window_size;
- if (window_start + window_size > map->file_size) {
- window_size = map->file_size - window_start;
- }
- if (offset + len > window_start + window_size) {
- window_size = (offset+len) - window_start;
- }
+ if (window_start + window_size > map->file_size)
+ window_size = (int32)(map->file_size - window_start);
+ if (window_size < len + align_fudge)
+ window_size = ALIGNED_LENGTH(len + align_fudge);
/* make sure we have allocated enough memory for the window */
if (window_size > map->p_size) {
map->p = realloc_array(map->p, char, window_size);
- if (!map->p)
- out_of_memory("map_ptr");
map->p_size = window_size;
}
- /* now try to avoid re-reading any bytes by reusing any bytes from the previous
- buffer. */
- if (window_start >= map->p_offset &&
- window_start < map->p_offset + map->p_len &&
- window_start + window_size >= map->p_offset + map->p_len) {
+ /* Now try to avoid re-reading any bytes by reusing any bytes from the previous buffer. */
+ if (window_start >= map->p_offset && window_start < map->p_offset + map->p_len
+ && window_start + window_size >= map->p_offset + map->p_len) {
read_start = map->p_offset + map->p_len;
- read_offset = read_start - window_start;
+ read_offset = (int32)(read_start - window_start);
read_size = window_size - read_offset;
memmove(map->p, map->p + (map->p_len - read_offset), read_offset);
} else {
}
if (read_size <= 0) {
- rprintf(FINFO,"Warning: unexpected read size of %d in map_ptr\n", read_size);
- } else {
- if (map->p_fd_offset != read_start) {
- if (do_lseek(map->fd,read_start,SEEK_SET) != read_start) {
- rprintf(FERROR,"lseek failed in map_ptr\n");
- exit_cleanup(RERR_FILEIO);
- }
- map->p_fd_offset = read_start;
- }
+ rprintf(FERROR, "invalid read_size of %ld in map_ptr\n",
+ (long)read_size);
+ exit_cleanup(RERR_FILEIO);
+ }
- if ((nread=read(map->fd,map->p + read_offset,read_size)) != read_size) {
- if (nread < 0) {
- nread = 0;
- if (!map->status)
- map->status = errno;
- }
- /* the best we can do is zero the buffer - the file
- has changed mid transfer! */
- memset(map->p+read_offset+nread, 0, read_size - nread);
+ if (map->p_fd_offset != read_start) {
+ OFF_T ret = do_lseek(map->fd, read_start, SEEK_SET);
+ if (ret != read_start) {
+ rsyserr(FERROR, errno, "lseek returned %s, not %s",
+ big_num(ret), big_num(read_start));
+ exit_cleanup(RERR_FILEIO);
}
- map->p_fd_offset += nread;
+ map->p_fd_offset = read_start;
}
-
map->p_offset = window_start;
map->p_len = window_size;
- return map->p + (offset - map->p_offset);
-}
+ while (read_size > 0) {
+ int32 nread = read(map->fd, map->p + read_offset, read_size);
+ if (nread <= 0) {
+ if (!map->status)
+ map->status = nread ? errno : ENODATA;
+ /* The best we can do is zero the buffer -- the file
+ * has changed mid transfer! */
+ memset(map->p + read_offset, 0, read_size);
+ break;
+ }
+ map->p_fd_offset += nread;
+ read_offset += nread;
+ read_size -= nread;
+ }
+ return map->p + align_fudge;
+}
int unmap_file(struct map_struct *map)
{
map->p = NULL;
}
ret = map->status;
- memset(map, 0, sizeof map[0]);
+#if 0 /* I don't think we really need this. */
+ force_memzero(map, sizeof map[0]);
+#endif
free(map);
return ret;