2013-06-16 00:49:09

by Namjae Jeon

[permalink] [raw]
Subject: [PATCH 1/2] f2fs: add remount_fs callback support

From: Namjae Jeon <[email protected]>

Add the f2fs_remount function call which will be used
during the filesystem remounting. This function
will help us to change the mount options specific to
f2fs.

Also modify the f2fs background_gc mount option, which
will allow the user to dynamically trun on/off the
garbage collection in f2fs based on the background_gc
value. If background_gc=on, Garbage collection will
be turned off & if background_gc=off, Garbage collection
will be truned on.

By default the garbage collection is on in f2fs.

Change Log:
v2: Incorporated the review comments by Gu Zheng.
Removing the restore part for VFS flags
Updating comments with proper flag conditions
Display GC background option as ON/OFF
Revised conditions to stop GC in case of remount

v1: Initial changes for adding remount_fs callback
support.

Cc: Gu Zheng <[email protected]>
Signed-off-by: Namjae Jeon <[email protected]>
Signed-off-by: Pankaj Kumar <[email protected]>
---
Documentation/filesystems/f2fs.txt | 9 +-
fs/f2fs/super.c | 235 +++++++++++++++++++++++-------------
2 files changed, 160 insertions(+), 84 deletions(-)

diff --git a/Documentation/filesystems/f2fs.txt b/Documentation/filesystems/f2fs.txt
index bd3c56c..b91e2f2 100644
--- a/Documentation/filesystems/f2fs.txt
+++ b/Documentation/filesystems/f2fs.txt
@@ -98,8 +98,13 @@ Cleaning Overhead
MOUNT OPTIONS
================================================================================

-background_gc_off Turn off cleaning operations, namely garbage collection,
- triggered in background when I/O subsystem is idle.
+background_gc=%s Turn on/off cleaning operations, namely garbage
+ collection, triggered in background when I/O subsystem is
+ idle. If background_gc=on, it will turn on the garbage
+ collection and if background_gc=off, garbage collection
+ will be truned off.
+ Default value for this option is on. So garbage
+ collection is on by default.
disable_roll_forward Disable the roll-forward recovery routine
discard Issue discard/TRIM commands when a segment is cleaned.
no_heap Disable heap-style segment allocation which finds free
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index ba56549..5a11484 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -34,7 +34,7 @@
static struct kmem_cache *f2fs_inode_cachep;

enum {
- Opt_gc_background_off,
+ Opt_gc_background,
Opt_disable_roll_forward,
Opt_discard,
Opt_noheap,
@@ -46,7 +46,7 @@ enum {
};

static match_table_t f2fs_tokens = {
- {Opt_gc_background_off, "background_gc_off"},
+ {Opt_gc_background, "background_gc=%s"},
{Opt_disable_roll_forward, "disable_roll_forward"},
{Opt_discard, "discard"},
{Opt_noheap, "no_heap"},
@@ -76,6 +76,91 @@ static void init_once(void *foo)
inode_init_once(&fi->vfs_inode);
}

+static int parse_options(struct super_block *sb, char *options)
+{
+ struct f2fs_sb_info *sbi = F2FS_SB(sb);
+ substring_t args[MAX_OPT_ARGS];
+ char *p, *name;
+ int arg = 0;
+
+ if (!options)
+ return 0;
+
+ while ((p = strsep(&options, ",")) != NULL) {
+ int token;
+ if (!*p)
+ continue;
+ /*
+ * Initialize args struct so we know whether arg was
+ * found; some options take optional arguments.
+ */
+ args[0].to = args[0].from = NULL;
+ token = match_token(p, f2fs_tokens, args);
+
+ switch (token) {
+ case Opt_gc_background:
+ name = match_strdup(&args[0]);
+
+ if (!name)
+ return -ENOMEM;
+ if (!strncmp(name, "on", 2))
+ set_opt(sbi, BG_GC);
+ else if (!strncmp(name, "off", 3))
+ clear_opt(sbi, BG_GC);
+ else {
+ kfree(name);
+ return -EINVAL;
+ }
+ kfree(name);
+ break;
+ case Opt_disable_roll_forward:
+ set_opt(sbi, DISABLE_ROLL_FORWARD);
+ break;
+ case Opt_discard:
+ set_opt(sbi, DISCARD);
+ break;
+ case Opt_noheap:
+ set_opt(sbi, NOHEAP);
+ break;
+#ifdef CONFIG_F2FS_FS_XATTR
+ case Opt_nouser_xattr:
+ clear_opt(sbi, XATTR_USER);
+ break;
+#else
+ case Opt_nouser_xattr:
+ f2fs_msg(sb, KERN_INFO,
+ "nouser_xattr options not supported");
+ break;
+#endif
+#ifdef CONFIG_F2FS_FS_POSIX_ACL
+ case Opt_noacl:
+ clear_opt(sbi, POSIX_ACL);
+ break;
+#else
+ case Opt_noacl:
+ f2fs_msg(sb, KERN_INFO, "noacl options not supported");
+ break;
+#endif
+ case Opt_active_logs:
+ if (args->from && match_int(args, &arg))
+ return -EINVAL;
+ if (arg != 2 && arg != 4 && arg != NR_CURSEG_TYPE)
+ return -EINVAL;
+ sbi->active_logs = arg;
+ break;
+ case Opt_disable_ext_identify:
+ set_opt(sbi, DISABLE_EXT_IDENTIFY);
+ break;
+ default:
+ f2fs_msg(sb, KERN_ERR,
+ "Unrecognized mount option \"%s\" or missing value",
+ p);
+ return -EINVAL;
+ }
+ }
+ return 0;
+}
+
static struct inode *f2fs_alloc_inode(struct super_block *sb)
{
struct f2fs_inode_info *fi;
@@ -225,10 +310,10 @@ static int f2fs_show_options(struct seq_file *seq, struct dentry *root)
{
struct f2fs_sb_info *sbi = F2FS_SB(root->d_sb);

- if (test_opt(sbi, BG_GC))
- seq_puts(seq, ",background_gc_on");
+ if (!(root->d_sb->s_flags & MS_RDONLY) && test_opt(sbi, BG_GC))
+ seq_printf(seq, ",background_gc=%s", "on");
else
- seq_puts(seq, ",background_gc_off");
+ seq_printf(seq, ",background_gc=%s", "off");
if (test_opt(sbi, DISABLE_ROLL_FORWARD))
seq_puts(seq, ",disable_roll_forward");
if (test_opt(sbi, DISCARD))
@@ -255,6 +340,58 @@ static int f2fs_show_options(struct seq_file *seq, struct dentry *root)
return 0;
}

+static int f2fs_remount(struct super_block *sb, int *flags, char *data)
+{
+ struct f2fs_sb_info *sbi = F2FS_SB(sb);
+ struct f2fs_mount_info org_mount_opt;
+ int err, active_logs;
+
+ /**
+ * Save the old mount options in case we
+ * need to restore them.
+ */
+ org_mount_opt = sbi->mount_opt;
+ active_logs = sbi->active_logs;
+
+ /* parse mount options */
+ err = parse_options(sb, data);
+ if (err)
+ goto restore_opts;
+
+ /**
+ * Previous and new state of filesystem is RO,
+ * so no point in checking GC conditions.
+ */
+ if ((sb->s_flags & MS_RDONLY) && (*flags & MS_RDONLY))
+ goto skip;
+
+ /**
+ * We stop the GC thread if FS is mounted as RO
+ * or if background_gc = off is passed in mount
+ * option. Also sync the filesystem.
+ */
+ if ((*flags & MS_RDONLY) || !test_opt(sbi, BG_GC)) {
+ if (sbi->gc_thread) {
+ stop_gc_thread(sbi);
+ f2fs_sync_fs(sb, 1);
+ }
+ } else if (test_opt(sbi, BG_GC) && !sbi->gc_thread) {
+ err = start_gc_thread(sbi);
+ if (err)
+ goto restore_opts;
+ }
+skip:
+ /* Update the POSIXACL Flag */
+ sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
+ (test_opt(sbi, POSIX_ACL) ? MS_POSIXACL : 0);
+ return 0;
+
+restore_opts:
+ sbi->mount_opt = org_mount_opt;
+ sbi->active_logs = active_logs;
+ return err;
+}
+
static struct super_operations f2fs_sops = {
.alloc_inode = f2fs_alloc_inode,
.drop_inode = f2fs_drop_inode,
@@ -268,6 +405,7 @@ static struct super_operations f2fs_sops = {
.freeze_fs = f2fs_freeze,
.unfreeze_fs = f2fs_unfreeze,
.statfs = f2fs_statfs,
+ .remount_fs = f2fs_remount,
};

static struct inode *f2fs_nfs_get_inode(struct super_block *sb,
@@ -315,79 +453,6 @@ static const struct export_operations f2fs_export_ops = {
.get_parent = f2fs_get_parent,
};

-static int parse_options(struct super_block *sb, char *options)
-{
- struct f2fs_sb_info *sbi = F2FS_SB(sb);
- substring_t args[MAX_OPT_ARGS];
- char *p;
- int arg = 0;
-
- if (!options)
- return 0;
-
- while ((p = strsep(&options, ",")) != NULL) {
- int token;
- if (!*p)
- continue;
- /*
- * Initialize args struct so we know whether arg was
- * found; some options take optional arguments.
- */
- args[0].to = args[0].from = NULL;
- token = match_token(p, f2fs_tokens, args);
-
- switch (token) {
- case Opt_gc_background_off:
- clear_opt(sbi, BG_GC);
- break;
- case Opt_disable_roll_forward:
- set_opt(sbi, DISABLE_ROLL_FORWARD);
- break;
- case Opt_discard:
- set_opt(sbi, DISCARD);
- break;
- case Opt_noheap:
- set_opt(sbi, NOHEAP);
- break;
-#ifdef CONFIG_F2FS_FS_XATTR
- case Opt_nouser_xattr:
- clear_opt(sbi, XATTR_USER);
- break;
-#else
- case Opt_nouser_xattr:
- f2fs_msg(sb, KERN_INFO,
- "nouser_xattr options not supported");
- break;
-#endif
-#ifdef CONFIG_F2FS_FS_POSIX_ACL
- case Opt_noacl:
- clear_opt(sbi, POSIX_ACL);
- break;
-#else
- case Opt_noacl:
- f2fs_msg(sb, KERN_INFO, "noacl options not supported");
- break;
-#endif
- case Opt_active_logs:
- if (args->from && match_int(args, &arg))
- return -EINVAL;
- if (arg != 2 && arg != 4 && arg != NR_CURSEG_TYPE)
- return -EINVAL;
- sbi->active_logs = arg;
- break;
- case Opt_disable_ext_identify:
- set_opt(sbi, DISABLE_EXT_IDENTIFY);
- break;
- default:
- f2fs_msg(sb, KERN_ERR,
- "Unrecognized mount option \"%s\" or missing value",
- p);
- return -EINVAL;
- }
- }
- return 0;
-}
-
static loff_t max_file_size(unsigned bits)
{
loff_t result = ADDRS_PER_INODE;
@@ -686,10 +751,16 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
"Cannot recover all fsync data errno=%ld", err);
}

- /* After POR, we can run background GC thread */
- err = start_gc_thread(sbi);
- if (err)
- goto fail;
+ /**
+ * If filesystem is not mounted as read-only then
+ * do start the gc_thread.
+ */
+ if (!(sb->s_flags & MS_RDONLY)) {
+ /* After POR, we can run background GC thread.*/
+ err = start_gc_thread(sbi);
+ if (err)
+ goto fail;
+ }

err = f2fs_build_stats(sbi);
if (err)
--
1.7.9.5


2013-06-17 02:42:23

by Gu Zheng

[permalink] [raw]
Subject: Re: [PATCH 1/2] f2fs: add remount_fs callback support

On 06/16/2013 08:48 AM, Namjae Jeon wrote:

> From: Namjae Jeon <[email protected]>
>
> Add the f2fs_remount function call which will be used
> during the filesystem remounting. This function
> will help us to change the mount options specific to
> f2fs.
>
> Also modify the f2fs background_gc mount option, which
> will allow the user to dynamically trun on/off the
> garbage collection in f2fs based on the background_gc
> value. If background_gc=on, Garbage collection will
> be turned off & if background_gc=off, Garbage collection
> will be truned on.
>
> By default the garbage collection is on in f2fs.
>
> Change Log:
> v2: Incorporated the review comments by Gu Zheng.
> Removing the restore part for VFS flags
> Updating comments with proper flag conditions
> Display GC background option as ON/OFF
> Revised conditions to stop GC in case of remount
>
> v1: Initial changes for adding remount_fs callback
> support.
>
> Cc: Gu Zheng <[email protected]>
> Signed-off-by: Namjae Jeon <[email protected]>
> Signed-off-by: Pankaj Kumar <[email protected]>


Reviewed-by: Gu Zheng <[email protected]>

Thanks,
Gu

> ---
> Documentation/filesystems/f2fs.txt | 9 +-
> fs/f2fs/super.c | 235 +++++++++++++++++++++++-------------
> 2 files changed, 160 insertions(+), 84 deletions(-)
>
> diff --git a/Documentation/filesystems/f2fs.txt b/Documentation/filesystems/f2fs.txt
> index bd3c56c..b91e2f2 100644
> --- a/Documentation/filesystems/f2fs.txt
> +++ b/Documentation/filesystems/f2fs.txt
> @@ -98,8 +98,13 @@ Cleaning Overhead
> MOUNT OPTIONS
> ================================================================================
>
> -background_gc_off Turn off cleaning operations, namely garbage collection,
> - triggered in background when I/O subsystem is idle.
> +background_gc=%s Turn on/off cleaning operations, namely garbage
> + collection, triggered in background when I/O subsystem is
> + idle. If background_gc=on, it will turn on the garbage
> + collection and if background_gc=off, garbage collection
> + will be truned off.
> + Default value for this option is on. So garbage
> + collection is on by default.
> disable_roll_forward Disable the roll-forward recovery routine
> discard Issue discard/TRIM commands when a segment is cleaned.
> no_heap Disable heap-style segment allocation which finds free
> diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
> index ba56549..5a11484 100644
> --- a/fs/f2fs/super.c
> +++ b/fs/f2fs/super.c
> @@ -34,7 +34,7 @@
> static struct kmem_cache *f2fs_inode_cachep;
>
> enum {
> - Opt_gc_background_off,
> + Opt_gc_background,
> Opt_disable_roll_forward,
> Opt_discard,
> Opt_noheap,
> @@ -46,7 +46,7 @@ enum {
> };
>
> static match_table_t f2fs_tokens = {
> - {Opt_gc_background_off, "background_gc_off"},
> + {Opt_gc_background, "background_gc=%s"},
> {Opt_disable_roll_forward, "disable_roll_forward"},
> {Opt_discard, "discard"},
> {Opt_noheap, "no_heap"},
> @@ -76,6 +76,91 @@ static void init_once(void *foo)
> inode_init_once(&fi->vfs_inode);
> }
>
> +static int parse_options(struct super_block *sb, char *options)
> +{
> + struct f2fs_sb_info *sbi = F2FS_SB(sb);
> + substring_t args[MAX_OPT_ARGS];
> + char *p, *name;
> + int arg = 0;
> +
> + if (!options)
> + return 0;
> +
> + while ((p = strsep(&options, ",")) != NULL) {
> + int token;
> + if (!*p)
> + continue;
> + /*
> + * Initialize args struct so we know whether arg was
> + * found; some options take optional arguments.
> + */
> + args[0].to = args[0].from = NULL;
> + token = match_token(p, f2fs_tokens, args);
> +
> + switch (token) {
> + case Opt_gc_background:
> + name = match_strdup(&args[0]);
> +
> + if (!name)
> + return -ENOMEM;
> + if (!strncmp(name, "on", 2))
> + set_opt(sbi, BG_GC);
> + else if (!strncmp(name, "off", 3))
> + clear_opt(sbi, BG_GC);
> + else {
> + kfree(name);
> + return -EINVAL;
> + }
> + kfree(name);
> + break;
> + case Opt_disable_roll_forward:
> + set_opt(sbi, DISABLE_ROLL_FORWARD);
> + break;
> + case Opt_discard:
> + set_opt(sbi, DISCARD);
> + break;
> + case Opt_noheap:
> + set_opt(sbi, NOHEAP);
> + break;
> +#ifdef CONFIG_F2FS_FS_XATTR
> + case Opt_nouser_xattr:
> + clear_opt(sbi, XATTR_USER);
> + break;
> +#else
> + case Opt_nouser_xattr:
> + f2fs_msg(sb, KERN_INFO,
> + "nouser_xattr options not supported");
> + break;
> +#endif
> +#ifdef CONFIG_F2FS_FS_POSIX_ACL
> + case Opt_noacl:
> + clear_opt(sbi, POSIX_ACL);
> + break;
> +#else
> + case Opt_noacl:
> + f2fs_msg(sb, KERN_INFO, "noacl options not supported");
> + break;
> +#endif
> + case Opt_active_logs:
> + if (args->from && match_int(args, &arg))
> + return -EINVAL;
> + if (arg != 2 && arg != 4 && arg != NR_CURSEG_TYPE)
> + return -EINVAL;
> + sbi->active_logs = arg;
> + break;
> + case Opt_disable_ext_identify:
> + set_opt(sbi, DISABLE_EXT_IDENTIFY);
> + break;
> + default:
> + f2fs_msg(sb, KERN_ERR,
> + "Unrecognized mount option \"%s\" or missing value",
> + p);
> + return -EINVAL;
> + }
> + }
> + return 0;
> +}
> +
> static struct inode *f2fs_alloc_inode(struct super_block *sb)
> {
> struct f2fs_inode_info *fi;
> @@ -225,10 +310,10 @@ static int f2fs_show_options(struct seq_file *seq, struct dentry *root)
> {
> struct f2fs_sb_info *sbi = F2FS_SB(root->d_sb);
>
> - if (test_opt(sbi, BG_GC))
> - seq_puts(seq, ",background_gc_on");
> + if (!(root->d_sb->s_flags & MS_RDONLY) && test_opt(sbi, BG_GC))
> + seq_printf(seq, ",background_gc=%s", "on");
> else
> - seq_puts(seq, ",background_gc_off");
> + seq_printf(seq, ",background_gc=%s", "off");
> if (test_opt(sbi, DISABLE_ROLL_FORWARD))
> seq_puts(seq, ",disable_roll_forward");
> if (test_opt(sbi, DISCARD))
> @@ -255,6 +340,58 @@ static int f2fs_show_options(struct seq_file *seq, struct dentry *root)
> return 0;
> }
>
> +static int f2fs_remount(struct super_block *sb, int *flags, char *data)
> +{
> + struct f2fs_sb_info *sbi = F2FS_SB(sb);
> + struct f2fs_mount_info org_mount_opt;
> + int err, active_logs;
> +
> + /**
> + * Save the old mount options in case we
> + * need to restore them.
> + */
> + org_mount_opt = sbi->mount_opt;
> + active_logs = sbi->active_logs;
> +
> + /* parse mount options */
> + err = parse_options(sb, data);
> + if (err)
> + goto restore_opts;
> +
> + /**
> + * Previous and new state of filesystem is RO,
> + * so no point in checking GC conditions.
> + */
> + if ((sb->s_flags & MS_RDONLY) && (*flags & MS_RDONLY))
> + goto skip;
> +
> + /**
> + * We stop the GC thread if FS is mounted as RO
> + * or if background_gc = off is passed in mount
> + * option. Also sync the filesystem.
> + */
> + if ((*flags & MS_RDONLY) || !test_opt(sbi, BG_GC)) {
> + if (sbi->gc_thread) {
> + stop_gc_thread(sbi);
> + f2fs_sync_fs(sb, 1);
> + }
> + } else if (test_opt(sbi, BG_GC) && !sbi->gc_thread) {
> + err = start_gc_thread(sbi);
> + if (err)
> + goto restore_opts;
> + }
> +skip:
> + /* Update the POSIXACL Flag */
> + sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
> + (test_opt(sbi, POSIX_ACL) ? MS_POSIXACL : 0);
> + return 0;
> +
> +restore_opts:
> + sbi->mount_opt = org_mount_opt;
> + sbi->active_logs = active_logs;
> + return err;
> +}
> +
> static struct super_operations f2fs_sops = {
> .alloc_inode = f2fs_alloc_inode,
> .drop_inode = f2fs_drop_inode,
> @@ -268,6 +405,7 @@ static struct super_operations f2fs_sops = {
> .freeze_fs = f2fs_freeze,
> .unfreeze_fs = f2fs_unfreeze,
> .statfs = f2fs_statfs,
> + .remount_fs = f2fs_remount,
> };
>
> static struct inode *f2fs_nfs_get_inode(struct super_block *sb,
> @@ -315,79 +453,6 @@ static const struct export_operations f2fs_export_ops = {
> .get_parent = f2fs_get_parent,
> };
>
> -static int parse_options(struct super_block *sb, char *options)
> -{
> - struct f2fs_sb_info *sbi = F2FS_SB(sb);
> - substring_t args[MAX_OPT_ARGS];
> - char *p;
> - int arg = 0;
> -
> - if (!options)
> - return 0;
> -
> - while ((p = strsep(&options, ",")) != NULL) {
> - int token;
> - if (!*p)
> - continue;
> - /*
> - * Initialize args struct so we know whether arg was
> - * found; some options take optional arguments.
> - */
> - args[0].to = args[0].from = NULL;
> - token = match_token(p, f2fs_tokens, args);
> -
> - switch (token) {
> - case Opt_gc_background_off:
> - clear_opt(sbi, BG_GC);
> - break;
> - case Opt_disable_roll_forward:
> - set_opt(sbi, DISABLE_ROLL_FORWARD);
> - break;
> - case Opt_discard:
> - set_opt(sbi, DISCARD);
> - break;
> - case Opt_noheap:
> - set_opt(sbi, NOHEAP);
> - break;
> -#ifdef CONFIG_F2FS_FS_XATTR
> - case Opt_nouser_xattr:
> - clear_opt(sbi, XATTR_USER);
> - break;
> -#else
> - case Opt_nouser_xattr:
> - f2fs_msg(sb, KERN_INFO,
> - "nouser_xattr options not supported");
> - break;
> -#endif
> -#ifdef CONFIG_F2FS_FS_POSIX_ACL
> - case Opt_noacl:
> - clear_opt(sbi, POSIX_ACL);
> - break;
> -#else
> - case Opt_noacl:
> - f2fs_msg(sb, KERN_INFO, "noacl options not supported");
> - break;
> -#endif
> - case Opt_active_logs:
> - if (args->from && match_int(args, &arg))
> - return -EINVAL;
> - if (arg != 2 && arg != 4 && arg != NR_CURSEG_TYPE)
> - return -EINVAL;
> - sbi->active_logs = arg;
> - break;
> - case Opt_disable_ext_identify:
> - set_opt(sbi, DISABLE_EXT_IDENTIFY);
> - break;
> - default:
> - f2fs_msg(sb, KERN_ERR,
> - "Unrecognized mount option \"%s\" or missing value",
> - p);
> - return -EINVAL;
> - }
> - }
> - return 0;
> -}
> -
> static loff_t max_file_size(unsigned bits)
> {
> loff_t result = ADDRS_PER_INODE;
> @@ -686,10 +751,16 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
> "Cannot recover all fsync data errno=%ld", err);
> }
>
> - /* After POR, we can run background GC thread */
> - err = start_gc_thread(sbi);
> - if (err)
> - goto fail;
> + /**
> + * If filesystem is not mounted as read-only then
> + * do start the gc_thread.
> + */
> + if (!(sb->s_flags & MS_RDONLY)) {
> + /* After POR, we can run background GC thread.*/
> + err = start_gc_thread(sbi);
> + if (err)
> + goto fail;
> + }
>
> err = f2fs_build_stats(sbi);
> if (err)