| Message ID | 1302075231-13105-1-git-send-email-xin.zhong@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Just a (probably) short question. This means, one now can mount any subvolume which lies directly in another subvolume by name, as long as one passes the correct subvolrootid=X mount option? Thanks, Andreas Philipp On 06.04.2011 09:33, 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 | 42 +++++++++++++++++++++++++++++++++--------- > 1 files changed, 33 insertions(+), 9 deletions(-) > > diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c > index db0a827..b85fe78 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)); > @@ -815,6 +832,13 @@ 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; -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (MingW32) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iQIcBAEBAgAGBQJNnCaeAAoJEJIcBJ3+Xkgi8AYP/2kZW9AkQOJoCFQiDipTF5ck yeXqKAqaMnmry0XY3I3ideZKpFp5C1U6QqoA/uy/ieHDx1OPix+wciLuqo/uxbKj LG3bKJTEcZ5swdjY6oHsTp9iQFXn5tNHTb0Sayha6QaJgkQ/FU4AV5jPmXdN5DvE xGuaY08rvshE2Bm6nqG5KpRIeuaPoGRd7qFvorhzzMDZ1bEZ8OcbDy4q4SgTR3ji mgDARmtnh38IASIb5/6CXLVsCgMf2t4lKlXA6pwFXruKyOfxNBRUzPjyTNuuErli 6b4/eHPn4lmhNelvScnCs6zHxdRQQAheX4r7uRQ+eSQmR+6DzZg9p+1TJcfr3/mn 18LRhGaCgFs5mXVwA+5bDQghcTZpFAePRa5hDxUvw2XKBq2/fp8FEjyBtFbAYumW /i4/X0FWOABBrQuD7Pg+gEDXL4nFokJFGlxamqDgDlsMZaPL/RHD+eC3FAYO1dYU EJSPRAYQCery1jRpmFey5X6foh6QWj0QF/LL7jBx5/bMevsmbQkESntSgH2Tkhj8 eAeu2wvv8p1ctuMeTUDDLxjrot6ADLM+fYiNZ1RdPD6CDHdjo4GUL4wZ85P1ZyqS J33SgJFLjP74TZS96SCtOsugJV2N+5zmfzxkdsocT8uO4nRqSPF0dyxnXKdrbMN3 VpQaQIhLPLKJ7tJWAFhV =jIhF -----END PGP SIGNATURE----- -- 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
> -----Original Message----- > From: Andreas Philipp [mailto:philipp.andreas@gmail.com] > Sent: Wednesday, April 06, 2011 4:39 PM > To: Zhong, Xin > Cc: linux-btrfs@vger.kernel.org; Andreas Philipp > Subject: Re: [PATCH V3] Btrfs: fix subvolume mount by name problem when > default mount subvolume is set > > > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA1 > > Just a (probably) short question. This means, one now can mount any > subvolume which lies directly in another subvolume by name, as long as > one passes the correct subvolrootid=X mount option? Yes. That's exactly what this patch does. Thanks! > > Thanks, > Andreas Philipp > > On 06.04.2011 09:33, 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 | 42 +++++++++++++++++++++++++++++++++--------- > > 1 files changed, 33 insertions(+), 9 deletions(-) > > > > diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c > > index db0a827..b85fe78 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)); > > @@ -815,6 +832,13 @@ 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; > -----BEGIN PGP SIGNATURE----- > Version: GnuPG v1.4.9 (MingW32) > Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ > > iQIcBAEBAgAGBQJNnCaeAAoJEJIcBJ3+Xkgi8AYP/2kZW9AkQOJoCFQiDipTF5ck > yeXqKAqaMnmry0XY3I3ideZKpFp5C1U6QqoA/uy/ieHDx1OPix+wciLuqo/uxbKj > LG3bKJTEcZ5swdjY6oHsTp9iQFXn5tNHTb0Sayha6QaJgkQ/FU4AV5jPmXdN5DvE > xGuaY08rvshE2Bm6nqG5KpRIeuaPoGRd7qFvorhzzMDZ1bEZ8OcbDy4q4SgTR3ji > mgDARmtnh38IASIb5/6CXLVsCgMf2t4lKlXA6pwFXruKyOfxNBRUzPjyTNuuErli > 6b4/eHPn4lmhNelvScnCs6zHxdRQQAheX4r7uRQ+eSQmR+6DzZg9p+1TJcfr3/mn > 18LRhGaCgFs5mXVwA+5bDQghcTZpFAePRa5hDxUvw2XKBq2/fp8FEjyBtFbAYumW > /i4/X0FWOABBrQuD7Pg+gEDXL4nFokJFGlxamqDgDlsMZaPL/RHD+eC3FAYO1dYU > EJSPRAYQCery1jRpmFey5X6foh6QWj0QF/LL7jBx5/bMevsmbQkESntSgH2Tkhj8 > eAeu2wvv8p1ctuMeTUDDLxjrot6ADLM+fYiNZ1RdPD6CDHdjo4GUL4wZ85P1ZyqS > J33SgJFLjP74TZS96SCtOsugJV2N+5zmfzxkdsocT8uO4nRqSPF0dyxnXKdrbMN3 > VpQaQIhLPLKJ7tJWAFhV > =jIhF > -----END PGP SIGNATURE----- -- 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
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c index db0a827..b85fe78 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)); @@ -815,6 +832,13 @@ 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;
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 | 42 +++++++++++++++++++++++++++++++++--------- 1 files changed, 33 insertions(+), 9 deletions(-)