Attachment 12556 Details for Bug 11588 – Preliminary patch to support punching holes

[patch] Preliminary patch to support punching holes

sparse.diff (text/plain), 5.81 KB, created by Wayne Davison on 2016-10-08 18:18:13 UTC

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Creator: Wayne Davison

Created: 2016-10-08 18:18:13 UTC

Size: 5.81 KB

patch

obsolete

>diff --git a/configure.ac b/configure.ac
>index b5e4049..e01e124 100644
>--- a/configure.ac
>+++ b/configure.ac
>@@ -614,6 +614,36 @@ if test x"$rsync_cv_have_fallocate" = x"yes"; then
>     AC_DEFINE(HAVE_FALLOCATE, 1, [Define to 1 if you have the fallocate function and it compiles and links without error])
> fi
> 
>+AC_MSG_CHECKING([for FALLOC_FL_PUNCH_HOLE])
>+AC_PREPROC_IFELSE([AC_LANG_SOURCE([[
>+        #define _GNU_SOURCE 1
>+        #include <linux/falloc.h>
>+        #ifndef FALLOC_FL_PUNCH_HOLE
>+        #error FALLOC_FL_PUNCH_HOLE is missing
>+        #endif
>+    ]])], [
>+        AC_MSG_RESULT([yes])
>+        AC_DEFINE([HAVE_FALLOC_FL_PUNCH_HOLE], [1], [Define if FALLOC_FL_PUNCH_HOLE is available.])
>+    ], [
>+        AC_MSG_RESULT([no])
>+    ]
>+)
>+
>+AC_MSG_CHECKING([for FALLOC_FL_ZERO_RANGE])
>+AC_PREPROC_IFELSE([AC_LANG_SOURCE([[
>+        #define _GNU_SOURCE 1
>+        #include <linux/falloc.h>
>+        #ifndef FALLOC_FL_ZERO_RANGE
>+        #error FALLOC_FL_ZERO_RANGE is missing
>+        #endif
>+    ]])], [
>+        AC_MSG_RESULT([yes])
>+        AC_DEFINE([HAVE_FALLOC_FL_ZERO_RANGE], [1], [Define if FALLOC_FL_ZERO_RANGE is available.])
>+    ], [
>+        AC_MSG_RESULT([no])
>+    ]
>+)
>+
> AC_CACHE_CHECK([for SYS_fallocate],rsync_cv_have_sys_fallocate,[
> AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <sys/syscall.h>
> #include <sys/types.h>]], [[syscall(SYS_fallocate, 0, 0, (loff_t)0, (loff_t)0);]])],[rsync_cv_have_sys_fallocate=yes],[rsync_cv_have_sys_fallocate=no])])
>diff --git a/fileio.c b/fileio.c
>index 70e079d..7b9caf7 100644
>--- a/fileio.c
>+++ b/fileio.c
>@@ -34,8 +34,11 @@
> #define ALIGNED_LENGTH(len) ((((len) - 1) | (ALIGN_BOUNDRY-1)) + 1)
> 
> extern int sparse_files;
>+extern int inplace;
>+extern int preallocate_files;
> 
> static OFF_T sparse_seek = 0;
>+static OFF_T sparse_last_write = 0;
> 
> int sparse_end(int f, OFF_T size)
> {
>@@ -63,8 +66,9 @@ int sparse_end(int f, OFF_T size)
> 	return ret;
> }
> 
>-
>-static int write_sparse(int f, char *buf, int len)
>+/* Note that the offset is just the caller letting us know where
>+ * the current file position is in the file. */
>+static int write_sparse(int f, OFF_T offset, const char *buf, int len)
> {
> 	int l1 = 0, l2 = 0;
> 	int ret;
>@@ -77,9 +81,14 @@ static int write_sparse(int f, char *buf, int len)
> 	if (l1 == len)
> 		return len;
> 
>-	if (sparse_seek)
>-		do_lseek(f, sparse_seek, SEEK_CUR);
>+	if (sparse_seek) {
>+		if (!inplace && !preallocate_files)
>+			do_lseek(f, sparse_seek, SEEK_CUR);
>+		else if (do_punch_hole(f, sparse_last_write, sparse_seek) < 0)
>+			return -1;
>+	}
> 	sparse_seek = l2;
>+	sparse_last_write = offset + len - l2;
> 
> 	while ((ret = write(f, buf + l1, len - (l1+l2))) <= 0) {
> 		if (ret < 0 && errno == EINTR)
>@@ -121,9 +130,11 @@ int flush_write_file(int f)
> 
> /*
>  * write_file does not allow incomplete writes.  It loops internally
>- * until len bytes are written or errno is set.
>+ * until len bytes are written or errno is set.  Note that "offset"
>+ * cannot be used to set a different location in the file -- it is
>+ * just used to interface with write_sparse().
>  */
>-int write_file(int f, char *buf, int len)
>+int write_file(int f, OFF_T offset, char *buf, int len)
> {
> 	int ret = 0;
> 
>@@ -131,7 +142,7 @@ int write_file(int f, char *buf, int len)
> 		int r1;
> 		if (sparse_files > 0) {
> 			int len1 = MIN(len, SPARSE_WRITE_SIZE);
>-			r1 = write_sparse(f, buf, len1);
>+			r1 = write_sparse(f, offset, buf, len1);
> 		} else {
> 			if (!wf_writeBuf) {
> 				wf_writeBufSize = WRITE_SIZE * 8;
>diff --git a/options.c b/options.c
>index 308443b..85b1f08 100644
>--- a/options.c
>+++ b/options.c
>@@ -2237,13 +2237,15 @@ int parse_arguments(int *argc_p, const char ***argv_p)
> 			bwlimit_writemax = 512;
> 	}
> 
>+#if !defined HAVE_FALLOCATE || !defined HAVE_FALLOC_FL_PUNCH_HOLE
> 	if (sparse_files && inplace) {
> 		/* Note: we don't check for this below, because --append is
> 		 * OK with --sparse (as long as redos are handled right). */
> 		snprintf(err_buf, sizeof err_buf,
>-			 "--sparse cannot be used with --inplace\n");
>+			 "This rsync cannot combine --sparse with --inplace\n");
> 		return 0;
> 	}
>+#endif
> 
> 	if (append_mode) {
> 		if (whole_file > 0) {
>diff --git a/receiver.c b/receiver.c
>index f9b97dd..d702603 100644
>--- a/receiver.c
>+++ b/receiver.c
>@@ -318,7 +318,7 @@ static int receive_data(int f_in, char *fname_r, int fd_r, OFF_T size_r,
> 
> 			sum_update(data, i);
> 
>-			if (fd != -1 && write_file(fd,data,i) != i)
>+			if (fd != -1 && write_file(fd, offset, data, i) != i)
> 				goto report_write_error;
> 			offset += i;
> 			continue;
>@@ -362,7 +362,7 @@ static int receive_data(int f_in, char *fname_r, int fd_r, OFF_T size_r,
> 				continue;
> 			}
> 		}
>-		if (fd != -1 && map && write_file(fd, map, len) != (int)len)
>+		if (fd != -1 && map && write_file(fd, offset, map, len) != (int)len)
> 			goto report_write_error;
> 		offset += len;
> 	}
>diff --git a/syscall.c b/syscall.c
>index ecca2f1..ae5eeff 100644
>--- a/syscall.c
>+++ b/syscall.c
>@@ -444,6 +444,40 @@ int do_fallocate(int fd, OFF_T offset, OFF_T length)
> }
> #endif
> 
>+/* NOTE: the offset must be the same as the current file position! */
>+int do_punch_hole(int fd, OFF_T offset, int len)
>+{
>+#ifdef HAVE_FALLOCATE
>+# ifdef HAVE_FALLOC_FL_PUNCH_HOLE
>+	if (fallocate(fd, FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE, offset, len) == 0) {
>+		do_lseek(fd, offset + len, SEEK_SET);
>+		return 0;
>+	}
>+# endif
>+# ifdef HAVE_FALLOC_FL_ZERO_RANGE
>+	if (fallocate(fd, FALLOC_FL_ZERO_RANGE, offset, len) == 0) {
>+		do_lseek(fd, offset + len, SEEK_SET);
>+		return 0;
>+	}
>+# endif
>+#endif
>+	{
>+		char zeros[4096];
>+		memset(zeros, 0, sizeof zeros);
>+		while (len > 0) {
>+			int chunk = len > (int)sizeof zeros ? (int)sizeof zeros : len;
>+			int wrote = write(fd, zeros, chunk);
>+			if (wrote <= 0) {
>+				if (wrote < 0 && errno == EINTR)
>+					continue;
>+				return -1;
>+			}
>+			len -= wrote;
>+		}
>+	}
>+	return 0;
>+}
>+
> int do_open_nofollow(const char *pathname, int flags)
> {
> #ifndef O_NOFOLLOW

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Attachments on bug 11588: 12556 | 12557