On 11/29/2017 12:07 AM, David Sterba wrote:
On Tue, Nov 28, 2017 at 05:14:50PM +0800, Su Yue wrote:
Now, files which have nocompress flag also will be defraged
with compression. However, nocompress flag is still existed
and have to be cleared manually.
So add an option '--clear-nocompress' to extend -c to drop
nocompress flag after defragement.
Suggested-by: David Sterba <dsterba@xxxxxxxx>
Suggested-by: Anand Jain <anand.jain@xxxxxxxxxx>
Do you have the pointer to the discussion? The whole idea sounds
familiar and seeing my name here means I must have been involved, but I
have only vague memories.
Here is the link:
https://www.spinics.net/lists/linux-btrfs/msg67529.html
Signed-off-by: Su Yue <suy.fnst@xxxxxxxxxxxxxx>
---
Changelog:
v2: Remove change about indentation of defrag_callback().
---
cmds-filesystem.c | 65 ++++++++++++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 64 insertions(+), 1 deletion(-)
diff --git a/cmds-filesystem.c b/cmds-filesystem.c
index 3931333f76c6..84242814798e 100644
--- a/cmds-filesystem.c
+++ b/cmds-filesystem.c
@@ -27,6 +27,7 @@
#include <mntent.h>
#include <linux/limits.h>
#include <getopt.h>
+#include <linux/fs.h>
#include "kerncompat.h"
#include "ctree.h"
@@ -867,6 +868,8 @@ static const char * const cmd_filesystem_defrag_usage[] = {
"-l len defragment only up to len bytes",
"-t size target extent size hint (default: 32M)",
"",
+ "--compress-force clear nocompress flag on files after defragment, only work with option -c",
This is probably --clear-nocompress .
Oh... I forgot to change the usage info here.
The "force compress" semantics is up to kernel, so I think naming the
options 'clear-nocompress' is the right thing, as it's what it really
does.
+ "",
"Warning: most Linux kernels will break up the ref-links of COW data",
"(e.g., files copied with 'cp --reflink', snapshots) which may cause",
"considerable increase of space usage. See btrfs-filesystem(8) for",
@@ -874,9 +877,39 @@ static const char * const cmd_filesystem_defrag_usage[] = {
NULL
};
+static int clear_nocompress_flag(int fd)
+{
+ unsigned int flags;
+ int ret = 0;
+
+ ret = ioctl(fd, FS_IOC_GETFLAGS, &flags);
+ if (ret < 0) {
+ ret = -errno;
+ error("failed to get flags: %s", strerror(-ret));
+ goto out;
+ }
+
+ if (!(flags & FS_NOCOMP_FL)) {
+ ret = 0;
+ goto out;
+ }
+ flags &= ~FS_NOCOMP_FL;
+ ret = ioctl(fd, FS_IOC_SETFLAGS, &flags);
This is inherently racy, but the inode flags do not change that often so
concurrent change is unlikely.
I don't quite understand what you mean.
Could you explain some details?
Thanks,
Su
+ if (ret < 0) {
+ ret = -errno;
+ error("failed to set flags: %s", strerror(-ret));
+ goto out;
+ }
+
+ ret = 0;
+out:
+ return ret;
+}
+
static struct btrfs_ioctl_defrag_range_args defrag_global_range;
static int defrag_global_verbose;
static int defrag_global_errors;
+static int defrag_global_clear_nocompress;
static int defrag_callback(const char *fpath, const struct stat *sb,
int typeflag, struct FTW *ftwbuf)
{
@@ -904,6 +937,14 @@ static int defrag_callback(const char *fpath, const struct stat *sb,
err = errno;
goto error;
}
+
+ if (defrag_global_clear_nocompress) {
+ ret = clear_nocompress_flag(fd);
+ if (ret) {
+ err = -ret;
+ goto error;
+ }
+ }
}
return 0;
@@ -926,6 +967,12 @@ static int cmd_filesystem_defrag(int argc, char **argv)
int compress_type = BTRFS_COMPRESS_NONE;
DIR *dirstream;
+ enum { GETOPT_VAL_CLEAR_NOCOMPRESS = 257};
+ static const struct option long_options[] = {
+ { "clear-nocompress", no_argument, NULL,
+ GETOPT_VAL_CLEAR_NOCOMPRESS},
+ { NULL, 0, NULL, 0}
+ };
/*
* Kernel has a different default (256K) that is supposed to be safe,
* but it does not defragment very well. The 32M will likely lead to
@@ -937,8 +984,10 @@ static int cmd_filesystem_defrag(int argc, char **argv)
defrag_global_errors = 0;
defrag_global_verbose = 0;
defrag_global_errors = 0;
+ defrag_global_clear_nocompress = 0;
while(1) {
- int c = getopt(argc, argv, "vrc::fs:l:t:");
+ int c = getopt_long(argc, argv, "vrc::fs:l:t:", long_options,
+ NULL);
if (c < 0)
break;
@@ -972,6 +1021,9 @@ static int cmd_filesystem_defrag(int argc, char **argv)
case 'r':
recursive = 1;
break;
+ case GETOPT_VAL_CLEAR_NOCOMPRESS:
+ defrag_global_clear_nocompress = 1;
+ break;
default:
usage(cmd_filesystem_defrag_usage);
}
@@ -987,6 +1039,8 @@ static int cmd_filesystem_defrag(int argc, char **argv)
if (compress_type) {
defrag_global_range.flags |= BTRFS_DEFRAG_RANGE_COMPRESS;
defrag_global_range.compress_type = compress_type;
+ } else if (defrag_global_clear_nocompress) {
+ warning("Option --clear-nocompress only works for -c");
}
if (flush)
defrag_global_range.flags |= BTRFS_DEFRAG_RANGE_START_IO;
@@ -1071,6 +1125,15 @@ static int cmd_filesystem_defrag(int argc, char **argv)
strerror(defrag_err));
goto next;
}
+
+ if (defrag_global_clear_nocompress)
+ ret = clear_nocompress_flag(fd);
+ if (ret) {
+ error(
+ "failed to drop nocompress flag on %s: %s",
+ argv[i], strerror(-ret));
+ goto next;
+ }
}
next:
if (ret)
--
2.15.0
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