Zhong, Xin
2011-Apr-06 05:27 UTC
[PATCH V2] Btrfs: fix subvolume mount by name problem when default mount subvolume is set
We create two subvolumes (meego_root and meego_home) in
btrfs root directory. And set meego_root as default mount
subvolume. After we remount btrfs, meego_root is mounted
to top directory by default. Then when we try to mount
meego_home (subvol=meego_home) to a subdirectory, it failed.
The problem is when default mount subvolume is set to
meego_root, we search meego_home in meego_root but can not find
it. So the solution is to add a new mount option (subvolrootid)
to specify subvol id of root and search subvol name in it. For
our case, now we can use "-o subvolrootid=0,subvol=meego_home)
to mount meego_home.
Detail information can be found in meego bugzilla:
https://bugs.meego.com/show_bug.cgi?id=15055
Signed-off-by: Zhong, Xin <xin.zhong@intel.com>
---
fs/btrfs/super.c | 43 ++++++++++++++++++++++++++++++++++---------
1 files changed, 34 insertions(+), 9 deletions(-)
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index db0a827..cd5f3ad 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -156,7 +156,7 @@ enum {
Opt_compress_type, Opt_compress_force, Opt_compress_force_type,
Opt_notreelog, Opt_ratio, Opt_flushoncommit, Opt_discard,
Opt_space_cache, Opt_clear_cache, Opt_user_subvol_rm_allowed,
- Opt_enospc_debug, Opt_err,
+ Opt_enospc_debug, Opt_subvolrootid, Opt_err,
};
static match_table_t tokens = {
@@ -186,6 +186,7 @@ static match_table_t tokens = {
{Opt_clear_cache, "clear_cache"},
{Opt_user_subvol_rm_allowed, "user_subvol_rm_allowed"},
{Opt_enospc_debug, "enospc_debug"},
+ {Opt_subvolrootid, "subvolrootid=%d"},
{Opt_err, NULL},
};
@@ -229,6 +230,7 @@ int btrfs_parse_options(struct btrfs_root *root, char
*options)
break;
case Opt_subvol:
case Opt_subvolid:
+ case Opt_subvolrootid:
case Opt_device:
/*
* These are parsed by btrfs_parse_early_options
@@ -385,7 +387,7 @@ out:
*/
static int btrfs_parse_early_options(const char *options, fmode_t flags,
void *holder, char **subvol_name, u64 *subvol_objectid,
- struct btrfs_fs_devices **fs_devices)
+ u64 *subvol_rootid, struct btrfs_fs_devices **fs_devices)
{
substring_t args[MAX_OPT_ARGS];
char *opts, *orig, *p;
@@ -426,6 +428,18 @@ static int btrfs_parse_early_options(const char *options,
fmode_t flags,
*subvol_objectid = intarg;
}
break;
+ case Opt_subvolrootid:
+ intarg = 0;
+ error = match_int(&args[0], &intarg);
+ if (!error) {
+ /* we want the original fs_tree */
+ if (!intarg)
+ *subvol_rootid + BTRFS_FS_TREE_OBJECTID;
+ else
+ *subvol_rootid = intarg;
+ }
+ break;
case Opt_device:
error = btrfs_scan_one_device(match_strdup(&args[0]),
flags, holder, fs_devices);
@@ -715,6 +729,7 @@ static int btrfs_get_sb(struct file_system_type *fs_type,
int flags,
fmode_t mode = FMODE_READ;
char *subvol_name = NULL;
u64 subvol_objectid = 0;
+ u64 subvol_rootid = 0;
int error = 0;
if (!(flags & MS_RDONLY))
@@ -722,7 +737,7 @@ static int btrfs_get_sb(struct file_system_type *fs_type,
int flags,
error = btrfs_parse_early_options(data, mode, fs_type,
&subvol_name, &subvol_objectid,
- &fs_devices);
+ &subvol_rootid, &fs_devices);
if (error)
return error;
@@ -786,15 +801,17 @@ static int btrfs_get_sb(struct file_system_type *fs_type,
int flags,
s->s_flags |= MS_ACTIVE;
}
- root = get_default_root(s, subvol_objectid);
- if (IS_ERR(root)) {
- error = PTR_ERR(root);
- deactivate_locked_super(s);
- goto error_free_subvol_name;
- }
/* if they gave us a subvolume name bind mount into that */
if (strcmp(subvol_name, ".")) {
struct dentry *new_root;
+
+ root = get_default_root(s, subvol_rootid);
+ if (IS_ERR(root)) {
+ error = PTR_ERR(root);
+ deactivate_locked_super(s);
+ goto error_free_subvol_name;
+ }
+
mutex_lock(&root->d_inode->i_mutex);
new_root = lookup_one_len(subvol_name, root,
strlen(subvol_name));
@@ -816,6 +833,14 @@ static int btrfs_get_sb(struct file_system_type *fs_type,
int flags,
dput(root);
root = new_root;
}
+ else {
+ root = get_default_root(s, subvol_objectid);
+ if (IS_ERR(root)) {
+ error = PTR_ERR(root);
+ deactivate_locked_super(s);
+ goto error_free_subvol_name;
+ }
+ }
mnt->mnt_sb = s;
mnt->mnt_root = root;
--
1.7.0.4
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Li Zefan
2011-Apr-06 06:34 UTC
Re: [PATCH V2] Btrfs: fix subvolume mount by name problem when default mount subvolume is set
13:27, Zhong, Xin wrote:> We create two subvolumes (meego_root and meego_home) in > btrfs root directory. And set meego_root as default mount > subvolume. After we remount btrfs, meego_root is mounted > to top directory by default. Then when we try to mount > meego_home (subvol=meego_home) to a subdirectory, it failed. > The problem is when default mount subvolume is set to > meego_root, we search meego_home in meego_root but can not find > it. So the solution is to add a new mount option (subvolrootid) > to specify subvol id of root and search subvol name in it. For > our case, now we can use "-o subvolrootid=0,subvol=meego_home) > to mount meego_home. > > Detail information can be found in meego bugzilla: > https://bugs.meego.com/show_bug.cgi?id=15055 > > Signed-off-by: Zhong, Xin <xin.zhong@intel.com> > --- > fs/btrfs/super.c | 43 ++++++++++++++++++++++++++++++++++--------- > 1 files changed, 34 insertions(+), 9 deletions(-) >I guess you forgot to run checkpatch.pl. ERROR: trailing whitespace #183: FILE: fs/btrfs/super.c:807: +^I^I$ ERROR: else should follow close brace ''}'' #198: FILE: fs/btrfs/super.c:836: } + else { total: 2 errors, 0 warnings, 100 lines checked -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Zhong, Xin
2011-Apr-06 07:13 UTC
[PATCH V2] Btrfs: fix subvolume mount by name problem when default mount subvolume is set
We create two subvolumes (meego_root and meego_home) in
btrfs root directory. And set meego_root as default mount
subvolume. After we remount btrfs, meego_root is mounted
to top directory by default. Then when we try to mount
meego_home (subvol=meego_home) to a subdirectory, it failed.
The problem is when default mount subvolume is set to
meego_root, we search meego_home in meego_root but can not find
it. So the solution is to add a new mount option (subvolrootid)
to specify subvol id of root and search subvol name in it. For
our case, now we can use "-o subvolrootid=0,subvol=meego_home)
to mount meego_home.
Detail information can be found in meego bugzilla:
https://bugs.meego.com/show_bug.cgi?id=15055
Signed-off-by: Zhong, Xin <xin.zhong@intel.com>
---
fs/btrfs/super.c | 43 ++++++++++++++++++++++++++++++++++---------
1 files changed, 34 insertions(+), 9 deletions(-)
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index db0a827..5e7bc51 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -156,7 +156,7 @@ enum {
Opt_compress_type, Opt_compress_force, Opt_compress_force_type,
Opt_notreelog, Opt_ratio, Opt_flushoncommit, Opt_discard,
Opt_space_cache, Opt_clear_cache, Opt_user_subvol_rm_allowed,
- Opt_enospc_debug, Opt_err,
+ Opt_enospc_debug, Opt_subvolrootid, Opt_err,
};
static match_table_t tokens = {
@@ -186,6 +186,7 @@ static match_table_t tokens = {
{Opt_clear_cache, "clear_cache"},
{Opt_user_subvol_rm_allowed, "user_subvol_rm_allowed"},
{Opt_enospc_debug, "enospc_debug"},
+ {Opt_subvolrootid, "subvolrootid=%d"},
{Opt_err, NULL},
};
@@ -229,6 +230,7 @@ int btrfs_parse_options(struct btrfs_root *root, char
*options)
break;
case Opt_subvol:
case Opt_subvolid:
+ case Opt_subvolrootid:
case Opt_device:
/*
* These are parsed by btrfs_parse_early_options
@@ -385,7 +387,7 @@ out:
*/
static int btrfs_parse_early_options(const char *options, fmode_t flags,
void *holder, char **subvol_name, u64 *subvol_objectid,
- struct btrfs_fs_devices **fs_devices)
+ u64 *subvol_rootid, struct btrfs_fs_devices **fs_devices)
{
substring_t args[MAX_OPT_ARGS];
char *opts, *orig, *p;
@@ -426,6 +428,18 @@ static int btrfs_parse_early_options(const char *options,
fmode_t flags,
*subvol_objectid = intarg;
}
break;
+ case Opt_subvolrootid:
+ intarg = 0;
+ error = match_int(&args[0], &intarg);
+ if (!error) {
+ /* we want the original fs_tree */
+ if (!intarg)
+ *subvol_rootid + BTRFS_FS_TREE_OBJECTID;
+ else
+ *subvol_rootid = intarg;
+ }
+ break;
case Opt_device:
error = btrfs_scan_one_device(match_strdup(&args[0]),
flags, holder, fs_devices);
@@ -715,6 +729,7 @@ static int btrfs_get_sb(struct file_system_type *fs_type,
int flags,
fmode_t mode = FMODE_READ;
char *subvol_name = NULL;
u64 subvol_objectid = 0;
+ u64 subvol_rootid = 0;
int error = 0;
if (!(flags & MS_RDONLY))
@@ -722,7 +737,7 @@ static int btrfs_get_sb(struct file_system_type *fs_type,
int flags,
error = btrfs_parse_early_options(data, mode, fs_type,
&subvol_name, &subvol_objectid,
- &fs_devices);
+ &subvol_rootid, &fs_devices);
if (error)
return error;
@@ -786,15 +801,17 @@ static int btrfs_get_sb(struct file_system_type *fs_type,
int flags,
s->s_flags |= MS_ACTIVE;
}
- root = get_default_root(s, subvol_objectid);
- if (IS_ERR(root)) {
- error = PTR_ERR(root);
- deactivate_locked_super(s);
- goto error_free_subvol_name;
- }
/* if they gave us a subvolume name bind mount into that */
if (strcmp(subvol_name, ".")) {
struct dentry *new_root;
+
+ root = get_default_root(s, subvol_rootid);
+ if (IS_ERR(root)) {
+ error = PTR_ERR(root);
+ deactivate_locked_super(s);
+ goto error_free_subvol_name;
+ }
+
mutex_lock(&root->d_inode->i_mutex);
new_root = lookup_one_len(subvol_name, root,
strlen(subvol_name));
@@ -816,6 +833,14 @@ static int btrfs_get_sb(struct file_system_type *fs_type,
int flags,
dput(root);
root = new_root;
}
+ } else {
+ root = get_default_root(s, subvol_objectid);
+ if (IS_ERR(root)) {
+ error = PTR_ERR(root);
+ deactivate_locked_super(s);
+ goto error_free_subvol_name;
+ }
+ }
mnt->mnt_sb = s;
mnt->mnt_root = root;
--
1.7.0.4
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Zhong, Xin
2011-Apr-06 08:10 UTC
RE: [PATCH V2] Btrfs: fix subvolume mount by name problem when default mount subvolume is set
> -----Original Message----- > From: linux-btrfs-owner@vger.kernel.org [mailto:linux-btrfs- > owner@vger.kernel.org] On Behalf Of Li Zefan > Sent: Wednesday, April 06, 2011 2:34 PM > To: Zhong, Xin > Cc: linux-btrfs@vger.kernel.org > Subject: Re: [PATCH V2] Btrfs: fix subvolume mount by name problem when > default mount subvolume is set > > 13:27, Zhong, Xin wrote: > > We create two subvolumes (meego_root and meego_home) in > > btrfs root directory. And set meego_root as default mount > > subvolume. After we remount btrfs, meego_root is mounted > > to top directory by default. Then when we try to mount > > meego_home (subvol=meego_home) to a subdirectory, it failed. > > The problem is when default mount subvolume is set to > > meego_root, we search meego_home in meego_root but can not find > > it. So the solution is to add a new mount option (subvolrootid) > > to specify subvol id of root and search subvol name in it. For > > our case, now we can use "-o subvolrootid=0,subvol=meego_home) > > to mount meego_home. > > > > Detail information can be found in meego bugzilla: > > https://bugs.meego.com/show_bug.cgi?id=15055 > > > > Signed-off-by: Zhong, Xin <xin.zhong@intel.com> > > --- > > fs/btrfs/super.c | 43 ++++++++++++++++++++++++++++++++++--------- > > 1 files changed, 34 insertions(+), 9 deletions(-) > > > > I guess you forgot to run checkpatch.pl.Sorry for my mistake. I have fixed it and resubmit. Thanks!> > ERROR: trailing whitespace > #183: FILE: fs/btrfs/super.c:807: > +^I^I$ > > ERROR: else should follow close brace '}' > #198: FILE: fs/btrfs/super.c:836: > } > + else { > > total: 2 errors, 0 warnings, 100 lines checked > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" > in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.htmlNrybXǧv^){.n+{n߲)w*jgݢj/zޖ2ޙ&)ߡaGhj:+vw٥
Possibly Parallel Threads
- [PATCH 0/5] Btrfs: mount error handling fixes
- [PATCH] btrfs: trivial fix, a potential memory leak in btrfs_parse_early_options()
- [PATCH RESEND 2/3] Btrfs: use u64 for subvolid when parsing mount options
- [PATCH] Btrfs: make subvol=0 mount the original default root
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