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authorChris Mason <chris.mason@oracle.com>2010-01-28 16:18:15 -0500
committerChris Mason <chris.mason@oracle.com>2010-01-28 16:18:15 -0500
commita555f810af6d63ea5960abaed88e150ad95c3011 (patch)
tree643fd3e94c352dc0006ff9333de8b7b4dc2b8785 /fs
parent11dfe35a0108097f2df1f042c485fa7f758c2cdf (diff)
Btrfs: Add mount -o compress-force
The default btrfs mount -o compress mode will quickly back off compressing a file if it notices that compression does not reduce the size of the data being written. This can save considerable CPU because all future writes to the file go through uncompressed. But some files are both very large and have mixed data stored in them. In that case, we want to add the ability to always try compressing data before writing it. This commit adds mount -o compress-force. A later commit will add a new inode flag that does the same thing. Signed-off-by: Chris Mason <chris.mason@oracle.com>
Diffstat (limited to 'fs')
-rw-r--r--fs/btrfs/ctree.h1
-rw-r--r--fs/btrfs/inode.c3
-rw-r--r--fs/btrfs/super.c9
3 files changed, 11 insertions, 2 deletions
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 9f806dd04c2..2aa8ec6a098 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -1161,6 +1161,7 @@ struct btrfs_root {
#define BTRFS_MOUNT_SSD_SPREAD (1 << 8)
#define BTRFS_MOUNT_NOSSD (1 << 9)
#define BTRFS_MOUNT_DISCARD (1 << 10)
+#define BTRFS_MOUNT_FORCE_COMPRESS (1 << 11)
#define btrfs_clear_opt(o, opt) ((o) &= ~BTRFS_MOUNT_##opt)
#define btrfs_set_opt(o, opt) ((o) |= BTRFS_MOUNT_##opt)
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index b330e27c2d8..f46c5727684 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -483,7 +483,8 @@ again:
nr_pages_ret = 0;
/* flag the file so we don't compress in the future */
- BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
+ if (!btrfs_test_opt(root, FORCE_COMPRESS))
+ BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
}
if (will_compress) {
*num_added += 1;
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 3f9b45704fc..8a1ea6e6457 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -66,7 +66,8 @@ enum {
Opt_degraded, Opt_subvol, Opt_device, Opt_nodatasum, Opt_nodatacow,
Opt_max_extent, Opt_max_inline, Opt_alloc_start, Opt_nobarrier,
Opt_ssd, Opt_nossd, Opt_ssd_spread, Opt_thread_pool, Opt_noacl,
- Opt_compress, Opt_notreelog, Opt_ratio, Opt_flushoncommit,
+ Opt_compress, Opt_compress_force, Opt_notreelog, Opt_ratio,
+ Opt_flushoncommit,
Opt_discard, Opt_err,
};
@@ -82,6 +83,7 @@ static match_table_t tokens = {
{Opt_alloc_start, "alloc_start=%s"},
{Opt_thread_pool, "thread_pool=%d"},
{Opt_compress, "compress"},
+ {Opt_compress_force, "compress-force"},
{Opt_ssd, "ssd"},
{Opt_ssd_spread, "ssd_spread"},
{Opt_nossd, "nossd"},
@@ -173,6 +175,11 @@ int btrfs_parse_options(struct btrfs_root *root, char *options)
printk(KERN_INFO "btrfs: use compression\n");
btrfs_set_opt(info->mount_opt, COMPRESS);
break;
+ case Opt_compress_force:
+ printk(KERN_INFO "btrfs: forcing compression\n");
+ btrfs_set_opt(info->mount_opt, FORCE_COMPRESS);
+ btrfs_set_opt(info->mount_opt, COMPRESS);
+ break;
case Opt_ssd:
printk(KERN_INFO "btrfs: use ssd allocation scheme\n");
btrfs_set_opt(info->mount_opt, SSD);