Commit d9c740d2 authored by Boaz Harrosh's avatar Boaz Harrosh

exofs: Define on-disk per-inode optional layout attribute

* Layouts describe the way a file is spread on multiple devices.
  The layout information is stored in the objects attribute introduced
  in this patch.

* There can be multiple generating function for the layout.
  Currently defined:
    - No attribute present - use below moving-window on global
      device table, all devices.
      (This is the only one currently used in exofs)
    - an obj_id generated moving window - the obj_id is a randomizing
      factor in the otherwise global map layout.
    - An explicit layout stored, including a data_map and a device
      index list.
    - More might be defined in future ...

* There are two attributes defined of the same structure:
  A-data-files-layout - This layout is used by data-files. If present
                        at a directory, all files of that directory will
                        be created with this layout.
  A-meta-data-layout - This layout is used by a directory and other
                       meta-data information. Also inherited at creation
                       of subdirectories.

* At creation time inodes are created with the layout specified above.
  A usermode utility may change the creation layout on a give directory
  or file. Which in the case of directories, will also apply to newly
  created files/subdirectories, children of that directory.
  In the simple unaltered case of a newly created exofs, no layout
  attributes are present, and all layouts adhere to the layout specified
  at the device-table.

* In case of a future file system loaded in an old exofs-driver.
  At iget(), the generating_function is inspected and if not supported
  will return an IO error to the application and the inode will not
  be loaded. So not to damage any data.
  Note: After this patch we do not yet support any type of layout
        only the RAID0 patch that enables striping at the super-block
        level will add support for RAID0 layouts above. This way we
        are past and future compatible and fully bisectable.

* Access to the device table is done by an accessor since
  it will change according to above information.
Signed-off-by: default avatarBoaz Harrosh <bharrosh@panasas.com>
parent 46f4d973
......@@ -55,6 +55,8 @@
/* exofs Application specific page/attribute */
# define EXOFS_APAGE_FS_DATA (OSD_APAGE_APP_DEFINED_FIRST + 3)
# define EXOFS_ATTR_INODE_DATA 1
# define EXOFS_ATTR_INODE_FILE_LAYOUT 2
# define EXOFS_ATTR_INODE_DIR_LAYOUT 3
/*
* The maximum number of files we can have is limited by the size of the
......@@ -206,4 +208,41 @@ enum {
(((name_len) + offsetof(struct exofs_dir_entry, name) + \
EXOFS_DIR_ROUND) & ~EXOFS_DIR_ROUND)
/*
* The on-disk (optional) layout structure.
* sits in an EXOFS_ATTR_INODE_FILE_LAYOUT or EXOFS_ATTR_INODE_DIR_LAYOUT
* attribute, attached to any inode, usually to a directory.
*/
enum exofs_inode_layout_gen_functions {
LAYOUT_MOVING_WINDOW = 0,
LAYOUT_IMPLICT = 1,
};
struct exofs_on_disk_inode_layout {
__le16 gen_func; /* One of enum exofs_inode_layout_gen_functions */
__le16 pad;
union {
/* gen_func == LAYOUT_MOVING_WINDOW (default) */
struct exofs_layout_sliding_window {
__le32 num_devices; /* first n devices in global-table*/
} sliding_window __packed;
/* gen_func == LAYOUT_IMPLICT */
struct exofs_layout_implict_list {
struct exofs_dt_data_map data_map;
/* Variable array of size data_map.cb_num_comps. These
* are device indexes of the devices in the global table
*/
__le32 dev_indexes[];
} implict __packed;
};
} __packed;
static inline size_t exofs_on_disk_inode_layout_size(unsigned max_devs)
{
return sizeof(struct exofs_on_disk_inode_layout) +
max_devs * sizeof(__le32);
}
#endif /*ifndef __EXOFS_COM_H__*/
......@@ -185,6 +185,12 @@ static inline struct exofs_i_info *exofs_i(struct inode *inode)
return container_of(inode, struct exofs_i_info, vfs_inode);
}
/*
* Given a layout, object_number and stripe_index return the associated global
* dev_index
*/
unsigned exofs_layout_od_id(struct exofs_layout *layout,
osd_id obj_no, unsigned layout_index);
/*
* Maximum count of links to a file
*/
......
......@@ -859,6 +859,15 @@ int exofs_setattr(struct dentry *dentry, struct iattr *iattr)
return error;
}
static const struct osd_attr g_attr_inode_file_layout = ATTR_DEF(
EXOFS_APAGE_FS_DATA,
EXOFS_ATTR_INODE_FILE_LAYOUT,
0);
static const struct osd_attr g_attr_inode_dir_layout = ATTR_DEF(
EXOFS_APAGE_FS_DATA,
EXOFS_ATTR_INODE_DIR_LAYOUT,
0);
/*
* Read an inode from the OSD, and return it as is. We also return the size
* attribute in the 'obj_size' argument.
......@@ -867,11 +876,16 @@ static int exofs_get_inode(struct super_block *sb, struct exofs_i_info *oi,
struct exofs_fcb *inode, uint64_t *obj_size)
{
struct exofs_sb_info *sbi = sb->s_fs_info;
struct osd_attr attrs[2];
struct osd_attr attrs[] = {
[0] = g_attr_inode_data,
[1] = g_attr_inode_file_layout,
[2] = g_attr_inode_dir_layout,
[3] = g_attr_logical_length,
};
struct exofs_io_state *ios;
struct exofs_on_disk_inode_layout *layout;
int ret;
*obj_size = ~0;
ret = exofs_get_io_state(&sbi->layout, &ios);
if (unlikely(ret)) {
EXOFS_ERR("%s: exofs_get_io_state failed.\n", __func__);
......@@ -882,8 +896,9 @@ static int exofs_get_inode(struct super_block *sb, struct exofs_i_info *oi,
exofs_make_credential(oi->i_cred, &ios->obj);
ios->cred = oi->i_cred;
attrs[0] = g_attr_inode_data;
attrs[1] = g_attr_logical_length;
attrs[1].len = exofs_on_disk_inode_layout_size(sbi->layout.s_numdevs);
attrs[2].len = exofs_on_disk_inode_layout_size(sbi->layout.s_numdevs);
ios->in_attr = attrs;
ios->in_attr_len = ARRAY_SIZE(attrs);
......@@ -900,12 +915,43 @@ static int exofs_get_inode(struct super_block *sb, struct exofs_i_info *oi,
memcpy(inode, attrs[0].val_ptr, EXOFS_INO_ATTR_SIZE);
ret = extract_attr_from_ios(ios, &attrs[1]);
if (ret) {
EXOFS_ERR("%s: extract_attr of inode_data failed\n", __func__);
goto out;
}
if (attrs[1].len) {
layout = attrs[1].val_ptr;
if (layout->gen_func != cpu_to_le16(LAYOUT_MOVING_WINDOW)) {
EXOFS_ERR("%s: unsupported files layout %d\n",
__func__, layout->gen_func);
ret = -ENOTSUPP;
goto out;
}
}
ret = extract_attr_from_ios(ios, &attrs[2]);
if (ret) {
EXOFS_ERR("%s: extract_attr of inode_data failed\n", __func__);
goto out;
}
if (attrs[2].len) {
layout = attrs[2].val_ptr;
if (layout->gen_func != cpu_to_le16(LAYOUT_MOVING_WINDOW)) {
EXOFS_ERR("%s: unsupported meta-data layout %d\n",
__func__, layout->gen_func);
ret = -ENOTSUPP;
goto out;
}
}
*obj_size = ~0;
ret = extract_attr_from_ios(ios, &attrs[3]);
if (ret) {
EXOFS_ERR("%s: extract_attr of logical_length failed\n",
__func__);
goto out;
}
*obj_size = get_unaligned_be64(attrs[1].val_ptr);
*obj_size = get_unaligned_be64(attrs[3].val_ptr);
out:
exofs_put_io_state(ios);
......
......@@ -107,6 +107,19 @@ void exofs_put_io_state(struct exofs_io_state *ios)
}
}
unsigned exofs_layout_od_id(struct exofs_layout *layout,
osd_id obj_no, unsigned layout_index)
{
return layout_index;
}
static inline struct osd_dev *exofs_ios_od(struct exofs_io_state *ios,
unsigned layout_index)
{
return ios->layout->s_ods[
exofs_layout_od_id(ios->layout, ios->obj.id, layout_index)];
}
static void _sync_done(struct exofs_io_state *ios, void *p)
{
struct completion *waiting = p;
......@@ -242,7 +255,7 @@ int exofs_sbi_create(struct exofs_io_state *ios)
for (i = 0; i < ios->layout->s_numdevs; i++) {
struct osd_request *or;
or = osd_start_request(ios->layout->s_ods[i], GFP_KERNEL);
or = osd_start_request(exofs_ios_od(ios, i), GFP_KERNEL);
if (unlikely(!or)) {
EXOFS_ERR("%s: osd_start_request failed\n", __func__);
ret = -ENOMEM;
......@@ -266,7 +279,7 @@ int exofs_sbi_remove(struct exofs_io_state *ios)
for (i = 0; i < ios->layout->s_numdevs; i++) {
struct osd_request *or;
or = osd_start_request(ios->layout->s_ods[i], GFP_KERNEL);
or = osd_start_request(exofs_ios_od(ios, i), GFP_KERNEL);
if (unlikely(!or)) {
EXOFS_ERR("%s: osd_start_request failed\n", __func__);
ret = -ENOMEM;
......@@ -290,7 +303,7 @@ int exofs_sbi_write(struct exofs_io_state *ios)
for (i = 0; i < ios->layout->s_numdevs; i++) {
struct osd_request *or;
or = osd_start_request(ios->layout->s_ods[i], GFP_KERNEL);
or = osd_start_request(exofs_ios_od(ios, i), GFP_KERNEL);
if (unlikely(!or)) {
EXOFS_ERR("%s: osd_start_request failed\n", __func__);
ret = -ENOMEM;
......@@ -361,7 +374,7 @@ int exofs_sbi_read(struct exofs_io_state *ios)
unsigned first_dev = (unsigned)ios->obj.id;
first_dev %= ios->layout->s_numdevs;
or = osd_start_request(ios->layout->s_ods[first_dev], GFP_KERNEL);
or = osd_start_request(exofs_ios_od(ios, first_dev), GFP_KERNEL);
if (unlikely(!or)) {
EXOFS_ERR("%s: osd_start_request failed\n", __func__);
return -ENOMEM;
......@@ -442,7 +455,7 @@ int exofs_oi_truncate(struct exofs_i_info *oi, u64 size)
for (i = 0; i < sbi->layout.s_numdevs; i++) {
struct osd_request *or;
or = osd_start_request(sbi->layout.s_ods[i], GFP_KERNEL);
or = osd_start_request(exofs_ios_od(ios, i), GFP_KERNEL);
if (unlikely(!or)) {
EXOFS_ERR("%s: osd_start_request failed\n", __func__);
ret = -ENOMEM;
......
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