| Message ID | 20190626083402.1895-3-anand.jain@oracle.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | readmirror feature | expand |
On Wed, Jun 26, 2019 at 04:34:01PM +0800, Anand Jain wrote: > Function call chain __btrfs_map_block()->find_live_mirror() uses > thread %pid to determine the %mirror_num for the read when mirror_num=0 > in the argument. > > This patch introduces a framework so that readmirror is a configurable > parameter, with default set to pid. > > Signed-off-by: Anand Jain <anand.jain@oracle.com> > --- > fs/btrfs/props.c | 41 +++++++++++++++++++++++++++++++++++++++++ > fs/btrfs/volumes.c | 9 ++++++++- > fs/btrfs/volumes.h | 6 ++++++ > 3 files changed, 55 insertions(+), 1 deletion(-) > > diff --git a/fs/btrfs/props.c b/fs/btrfs/props.c > index f9143f7c006d..0dc26a154a98 100644 > --- a/fs/btrfs/props.c > +++ b/fs/btrfs/props.c > @@ -10,6 +10,7 @@ > #include "ctree.h" > #include "xattr.h" > #include "compression.h" > +#include "volumes.h" > > #define BTRFS_PROP_HANDLERS_HT_BITS 8 > static DEFINE_HASHTABLE(prop_handlers_ht, BTRFS_PROP_HANDLERS_HT_BITS); > @@ -312,6 +313,39 @@ static const char *prop_compression_extract(struct inode *inode) > return NULL; > } > > +static int prop_readmirror_validate(struct inode *inode, const char *value, > + size_t len) > +{ > + struct btrfs_root *root = BTRFS_I(inode)->root; > + > + if (root->root_key.objectid != BTRFS_FS_TREE_OBJECTID) > + return -EINVAL; > + > + if (!len) > + return 0; > + > + return -EINVAL; > +} > + > +static int prop_readmirror_apply(struct inode *inode, const char *value, > + size_t len) > +{ > + struct btrfs_fs_devices *fs_devices = btrfs_sb(inode->i_sb)->fs_devices; > + > + fs_devices->readmirror_policy = BTRFS_READMIRROR_DEFAULT; > + > + return 0; > +} > + > +static const char *prop_readmirror_extract(struct inode *inode) > +{ > + /* > + * readmirror policy is applied for the whole FS, inheritance is not > + * applicable. > + */ Extract is the 'get' implementation of the property, not inheritance, or I don't understand what does the comment refer to. > + return NULL; The return value should reflect the status of the property, ie. basically the same value that would set the current state. > +} > + > static struct prop_handler prop_handlers[] = { > { > .xattr_name = XATTR_BTRFS_PREFIX "compression", > @@ -320,6 +354,13 @@ static struct prop_handler prop_handlers[] = { > .extract = prop_compression_extract, > .inheritable = 1 > }, > + { > + .xattr_name = XATTR_BTRFS_PREFIX "readmirror", > + .validate = prop_readmirror_validate, > + .apply = prop_readmirror_apply, > + .extract = prop_readmirror_extract, > + .inheritable = 0 > + }, > }; > > static int inherit_props(struct btrfs_trans_handle *trans, > diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c > index a13ddba1ebc3..d72850ed4f88 100644 > --- a/fs/btrfs/volumes.c > +++ b/fs/btrfs/volumes.c > @@ -5490,7 +5490,14 @@ static int find_live_mirror(struct btrfs_fs_info *fs_info, > else > num_stripes = map->num_stripes; > > - preferred_mirror = first + current->pid % num_stripes; > + switch(fs_info->fs_devices->readmirror_policy) { > + case BTRFS_READMIRROR_DEFAULT: > + /* fall through */ > + default: > + /* readmirror as per thread pid */ > + preferred_mirror = first + current->pid % num_stripes; > + break; > + } > > if (dev_replace_is_ongoing && > fs_info->dev_replace.cont_reading_from_srcdev_mode == > diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h > index 7f6aa1816409..e985d2133c0a 100644 > --- a/fs/btrfs/volumes.h > +++ b/fs/btrfs/volumes.h > @@ -219,6 +219,10 @@ BTRFS_DEVICE_GETSET_FUNCS(total_bytes); > BTRFS_DEVICE_GETSET_FUNCS(disk_total_bytes); > BTRFS_DEVICE_GETSET_FUNCS(bytes_used); > > +enum btrfs_readmirror_policy { > + BTRFS_READMIRROR_DEFAULT, > +}; > + > struct btrfs_fs_devices { > u8 fsid[BTRFS_FSID_SIZE]; /* FS specific uuid */ > u8 metadata_uuid[BTRFS_FSID_SIZE]; > @@ -269,6 +273,8 @@ struct btrfs_fs_devices { > struct kobject fsid_kobj; > struct kobject *device_dir_kobj; > struct completion kobj_unregister; > + > + int readmirror_policy; > }; > > #define BTRFS_BIO_INLINE_CSUM_SIZE 64 > -- > 2.20.1 (Apple Git-117)
> On 23 Jul 2019, at 10:57 PM, David Sterba <dsterba@suse.cz> wrote: > > On Wed, Jun 26, 2019 at 04:34:01PM +0800, Anand Jain wrote: >> Function call chain __btrfs_map_block()->find_live_mirror() uses >> thread %pid to determine the %mirror_num for the read when mirror_num=0 >> in the argument. >> >> This patch introduces a framework so that readmirror is a configurable >> parameter, with default set to pid. >> >> Signed-off-by: Anand Jain <anand.jain@oracle.com> >> --- >> fs/btrfs/props.c | 41 +++++++++++++++++++++++++++++++++++++++++ >> fs/btrfs/volumes.c | 9 ++++++++- >> fs/btrfs/volumes.h | 6 ++++++ >> 3 files changed, 55 insertions(+), 1 deletion(-) >> >> diff --git a/fs/btrfs/props.c b/fs/btrfs/props.c >> index f9143f7c006d..0dc26a154a98 100644 >> --- a/fs/btrfs/props.c >> +++ b/fs/btrfs/props.c >> @@ -10,6 +10,7 @@ >> #include "ctree.h" >> #include "xattr.h" >> #include "compression.h" >> +#include "volumes.h" >> >> #define BTRFS_PROP_HANDLERS_HT_BITS 8 >> static DEFINE_HASHTABLE(prop_handlers_ht, BTRFS_PROP_HANDLERS_HT_BITS); >> @@ -312,6 +313,39 @@ static const char *prop_compression_extract(struct inode *inode) >> return NULL; >> } >> >> +static int prop_readmirror_validate(struct inode *inode, const char *value, >> + size_t len) >> +{ >> + struct btrfs_root *root = BTRFS_I(inode)->root; >> + >> + if (root->root_key.objectid != BTRFS_FS_TREE_OBJECTID) >> + return -EINVAL; >> + >> + if (!len) >> + return 0; >> + >> + return -EINVAL; >> +} >> + >> +static int prop_readmirror_apply(struct inode *inode, const char *value, >> + size_t len) >> +{ >> + struct btrfs_fs_devices *fs_devices = btrfs_sb(inode->i_sb)->fs_devices; >> + >> + fs_devices->readmirror_policy = BTRFS_READMIRROR_DEFAULT; >> + >> + return 0; >> +} >> + >> +static const char *prop_readmirror_extract(struct inode *inode) >> +{ >> + /* >> + * readmirror policy is applied for the whole FS, inheritance is not >> + * applicable. >> + */ > > Extract is the 'get' implementation of the property, not inheritance, or > I don't understand what does the comment refer to. prop_handler::extract() is only used by inherit_props(). Readmirror property is for the volume/fsid so prop_handler::inheritable is set to 0. So inherit_props() doesn’t call extract() for readmirror. The getxattr still work using the xattr interface and will have to mount the root which is I think is ok which is similar to the admin only operations, otherwise we have to introduce a new ioctl. Thanks, Anand >> + return NULL; > > The return value should reflect the status of the property, ie. > basically the same value that would set the current state. > >> +} >> + >> static struct prop_handler prop_handlers[] = { >> { >> .xattr_name = XATTR_BTRFS_PREFIX "compression", >> @@ -320,6 +354,13 @@ static struct prop_handler prop_handlers[] = { >> .extract = prop_compression_extract, >> .inheritable = 1 >> }, >> + { >> + .xattr_name = XATTR_BTRFS_PREFIX "readmirror", >> + .validate = prop_readmirror_validate, >> + .apply = prop_readmirror_apply, >> + .extract = prop_readmirror_extract, >> + .inheritable = 0 >> + }, >> }; >> >> static int inherit_props(struct btrfs_trans_handle *trans, >> diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c >> index a13ddba1ebc3..d72850ed4f88 100644 >> --- a/fs/btrfs/volumes.c >> +++ b/fs/btrfs/volumes.c >> @@ -5490,7 +5490,14 @@ static int find_live_mirror(struct btrfs_fs_info *fs_info, >> else >> num_stripes = map->num_stripes; >> >> - preferred_mirror = first + current->pid % num_stripes; >> + switch(fs_info->fs_devices->readmirror_policy) { >> + case BTRFS_READMIRROR_DEFAULT: >> + /* fall through */ >> + default: >> + /* readmirror as per thread pid */ >> + preferred_mirror = first + current->pid % num_stripes; >> + break; >> + } >> >> if (dev_replace_is_ongoing && >> fs_info->dev_replace.cont_reading_from_srcdev_mode == >> diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h >> index 7f6aa1816409..e985d2133c0a 100644 >> --- a/fs/btrfs/volumes.h >> +++ b/fs/btrfs/volumes.h >> @@ -219,6 +219,10 @@ BTRFS_DEVICE_GETSET_FUNCS(total_bytes); >> BTRFS_DEVICE_GETSET_FUNCS(disk_total_bytes); >> BTRFS_DEVICE_GETSET_FUNCS(bytes_used); >> >> +enum btrfs_readmirror_policy { >> + BTRFS_READMIRROR_DEFAULT, >> +}; >> + >> struct btrfs_fs_devices { >> u8 fsid[BTRFS_FSID_SIZE]; /* FS specific uuid */ >> u8 metadata_uuid[BTRFS_FSID_SIZE]; >> @@ -269,6 +273,8 @@ struct btrfs_fs_devices { >> struct kobject fsid_kobj; >> struct kobject *device_dir_kobj; >> struct completion kobj_unregister; >> + >> + int readmirror_policy; >> }; >> >> #define BTRFS_BIO_INLINE_CSUM_SIZE 64 >> -- >> 2.20.1 (Apple Git-117)
diff --git a/fs/btrfs/props.c b/fs/btrfs/props.c index f9143f7c006d..0dc26a154a98 100644 --- a/fs/btrfs/props.c +++ b/fs/btrfs/props.c @@ -10,6 +10,7 @@ #include "ctree.h" #include "xattr.h" #include "compression.h" +#include "volumes.h" #define BTRFS_PROP_HANDLERS_HT_BITS 8 static DEFINE_HASHTABLE(prop_handlers_ht, BTRFS_PROP_HANDLERS_HT_BITS); @@ -312,6 +313,39 @@ static const char *prop_compression_extract(struct inode *inode) return NULL; } +static int prop_readmirror_validate(struct inode *inode, const char *value, + size_t len) +{ + struct btrfs_root *root = BTRFS_I(inode)->root; + + if (root->root_key.objectid != BTRFS_FS_TREE_OBJECTID) + return -EINVAL; + + if (!len) + return 0; + + return -EINVAL; +} + +static int prop_readmirror_apply(struct inode *inode, const char *value, + size_t len) +{ + struct btrfs_fs_devices *fs_devices = btrfs_sb(inode->i_sb)->fs_devices; + + fs_devices->readmirror_policy = BTRFS_READMIRROR_DEFAULT; + + return 0; +} + +static const char *prop_readmirror_extract(struct inode *inode) +{ + /* + * readmirror policy is applied for the whole FS, inheritance is not + * applicable. + */ + return NULL; +} + static struct prop_handler prop_handlers[] = { { .xattr_name = XATTR_BTRFS_PREFIX "compression", @@ -320,6 +354,13 @@ static struct prop_handler prop_handlers[] = { .extract = prop_compression_extract, .inheritable = 1 }, + { + .xattr_name = XATTR_BTRFS_PREFIX "readmirror", + .validate = prop_readmirror_validate, + .apply = prop_readmirror_apply, + .extract = prop_readmirror_extract, + .inheritable = 0 + }, }; static int inherit_props(struct btrfs_trans_handle *trans, diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index a13ddba1ebc3..d72850ed4f88 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -5490,7 +5490,14 @@ static int find_live_mirror(struct btrfs_fs_info *fs_info, else num_stripes = map->num_stripes; - preferred_mirror = first + current->pid % num_stripes; + switch(fs_info->fs_devices->readmirror_policy) { + case BTRFS_READMIRROR_DEFAULT: + /* fall through */ + default: + /* readmirror as per thread pid */ + preferred_mirror = first + current->pid % num_stripes; + break; + } if (dev_replace_is_ongoing && fs_info->dev_replace.cont_reading_from_srcdev_mode == diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h index 7f6aa1816409..e985d2133c0a 100644 --- a/fs/btrfs/volumes.h +++ b/fs/btrfs/volumes.h @@ -219,6 +219,10 @@ BTRFS_DEVICE_GETSET_FUNCS(total_bytes); BTRFS_DEVICE_GETSET_FUNCS(disk_total_bytes); BTRFS_DEVICE_GETSET_FUNCS(bytes_used); +enum btrfs_readmirror_policy { + BTRFS_READMIRROR_DEFAULT, +}; + struct btrfs_fs_devices { u8 fsid[BTRFS_FSID_SIZE]; /* FS specific uuid */ u8 metadata_uuid[BTRFS_FSID_SIZE]; @@ -269,6 +273,8 @@ struct btrfs_fs_devices { struct kobject fsid_kobj; struct kobject *device_dir_kobj; struct completion kobj_unregister; + + int readmirror_policy; }; #define BTRFS_BIO_INLINE_CSUM_SIZE 64
Function call chain __btrfs_map_block()->find_live_mirror() uses thread %pid to determine the %mirror_num for the read when mirror_num=0 in the argument. This patch introduces a framework so that readmirror is a configurable parameter, with default set to pid. Signed-off-by: Anand Jain <anand.jain@oracle.com> --- fs/btrfs/props.c | 41 +++++++++++++++++++++++++++++++++++++++++ fs/btrfs/volumes.c | 9 ++++++++- fs/btrfs/volumes.h | 6 ++++++ 3 files changed, 55 insertions(+), 1 deletion(-)