* 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: Boaz Harrosh <bharrosh@xxxxxxxxxxx>
---
fs/exofs/common.h | 39 ++++++++++++++++++++++++++++++++++++
fs/exofs/exofs.h | 6 +++++
fs/exofs/inode.c | 56 ++++++++++++++++++++++++++++++++++++++++++++++++----
fs/exofs/ios.c | 23 +++++++++++++++++----
4 files changed, 114 insertions(+), 10 deletions(-)
diff --git a/fs/exofs/common.h b/fs/exofs/common.h
index b1b178e..f0d5203 100644
--- a/fs/exofs/common.h
+++ b/fs/exofs/common.h
@@ -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__*/
diff --git a/fs/exofs/exofs.h b/fs/exofs/exofs.h
index 33c6856..09e3319 100644
--- a/fs/exofs/exofs.h
+++ b/fs/exofs/exofs.h
@@ -186,6 +186,12 @@ static inline struct exofs_i_info *exofs_i(struct inode *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
*/
#define EXOFS_LINK_MAX 32000
diff --git a/fs/exofs/inode.c b/fs/exofs/inode.c
index 03189a9..0163546 100644
--- a/fs/exofs/inode.c
+++ b/fs/exofs/inode.c
@@ -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);
@@ -901,11 +916,42 @@ static int exofs_get_inode(struct super_block *sb, struct exofs_i_info *oi,
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);
diff --git a/fs/exofs/ios.c b/fs/exofs/ios.c
index 4f67931..2b81f99 100644
--- a/fs/exofs/ios.c
+++ b/fs/exofs/ios.c
@@ -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;
--
1.6.6
--
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