(as of now just an experimental interface)
This patch introduces profs interface /proc/fs/btrfs/devlist,
which as of now exports all the members of kernel fs_devices.
The current /sys/fs/btrfs interface works when the fs is
mounted, and is on the file directory hierarchy and also has
the sysfs limitation max output of U64 per file.
Here btrfs procfs uses seq_file to export all the members of
fs_devices. Also shows the contents when device is not mounted,
but have registered with btrfs kernel (useful as an alternative
to buggy ready ioctl)
An attempt is made to follow the some standard file format
output such as ini. So that a simple warper python script will
provide end user useful interfaces.
Further planning to add few more members to the interface such as
group profile info. The long term idea is to make procfs
interface a onestop btrfs application interface for the device and
fs info from the kernel, where a simple python script can make
use of it.
Signed-off-by: Anand Jain <anand.j...@oracle.com>
---
fs/btrfs/Makefile | 2 +-
fs/btrfs/ctree.h | 4 +++
fs/btrfs/procfs.c | 45 ++++++++++++++++++++++++++
fs/btrfs/super.c | 4 +++
fs/btrfs/volumes.c | 94 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
fs/btrfs/volumes.h | 1 +
6 files changed, 149 insertions(+), 1 deletion(-)
create mode 100644 fs/btrfs/procfs.c
diff --git a/fs/btrfs/Makefile b/fs/btrfs/Makefile
index 6d1d0b9..134a62f 100644
--- a/fs/btrfs/Makefile
+++ b/fs/btrfs/Makefile
@@ -4,7 +4,7 @@ obj-$(CONFIG_BTRFS_FS) := btrfs.o
btrfs-y += super.o ctree.o extent-tree.o print-tree.o root-tree.o dir-item.o \
file-item.o inode-item.o inode-map.o disk-io.o \
transaction.o inode.o file.o tree-defrag.o \
- extent_map.o sysfs.o struct-funcs.o xattr.o ordered-data.o \
+ extent_map.o sysfs.o procfs.o struct-funcs.o xattr.o ordered-data.o \
extent_io.o volumes.o async-thread.o ioctl.o locking.o orphan.o \
export.o tree-log.o free-space-cache.o zlib.o lzo.o \
compression.o delayed-ref.o relocation.o delayed-inode.o scrub.o \
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 6db3d4b..600adc30 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -3909,6 +3909,10 @@ ssize_t btrfs_listxattr(struct dentry *dentry, char
*buffer, size_t size);
int btrfs_parse_options(struct btrfs_root *root, char *options);
int btrfs_sync_fs(struct super_block *sb, int wait);
+/* procfs.c */
+void btrfs_exit_procfs(void);
+void btrfs_init_procfs(void);
+
#ifdef CONFIG_PRINTK
__printf(2, 3)
void btrfs_printk(const struct btrfs_fs_info *fs_info, const char *fmt, ...);
diff --git a/fs/btrfs/procfs.c b/fs/btrfs/procfs.c
new file mode 100644
index 0000000..9c94c6c
--- /dev/null
+++ b/fs/btrfs/procfs.c
@@ -0,0 +1,45 @@
+#include <linux/seq_file.h>
+#include <linux/vmalloc.h>
+#include <linux/proc_fs.h>
+#include "ctree.h"
+#include "volumes.h"
+
+#define BTRFS_PROC_PATH "fs/btrfs"
+#define BTRFS_PROC_DEVLIST "devlist"
+
+struct proc_dir_entry *btrfs_proc_root;
+
+static int btrfs_devlist_show(struct seq_file *seq, void *offset)
+{
+ btrfs_print_devlist(seq);
+ return 0;
+}
+
+static int btrfs_seq_open(struct inode *inode, struct file *file)
+{
+ return single_open(file, btrfs_devlist_show, PDE_DATA(inode));
+}
+
+static const struct file_operations btrfs_seq_fops = {
+ .owner = THIS_MODULE,
+ .open = btrfs_seq_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+
+void btrfs_init_procfs(void)
+{
+ btrfs_proc_root = proc_mkdir(BTRFS_PROC_PATH, NULL);
+ if (btrfs_proc_root)
+ proc_create_data(BTRFS_PROC_DEVLIST, S_IRUGO, btrfs_proc_root,
+ &btrfs_seq_fops, NULL);
+ return;
+}
+
+void btrfs_exit_procfs(void)
+{
+ if (btrfs_proc_root)
+ remove_proc_entry(BTRFS_PROC_DEVLIST, btrfs_proc_root);
+ remove_proc_entry(BTRFS_PROC_PATH, NULL);
+}
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index d0f44d9..f545c24 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -1976,6 +1976,8 @@ static int __init init_btrfs_fs(void)
if (err)
goto free_hash;
+ btrfs_init_procfs();
+
btrfs_init_compress();
err = btrfs_init_cachep();
@@ -2048,6 +2050,7 @@ free_cachep:
btrfs_destroy_cachep();
free_compress:
btrfs_exit_compress();
+ btrfs_exit_procfs();
btrfs_exit_sysfs();
free_hash:
btrfs_hash_exit();
@@ -2066,6 +2069,7 @@ static void __exit exit_btrfs_fs(void)
extent_io_exit();
btrfs_interface_exit();
unregister_filesystem(&btrfs_fs_type);
+ btrfs_exit_procfs();
btrfs_exit_sysfs();
btrfs_cleanup_fs_uuids();
btrfs_exit_compress();
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 3e803c1..a526722 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -27,6 +27,7 @@
#include <linux/kthread.h>
#include <linux/raid/pq.h>
#include <linux/semaphore.h>
+#include <linux/seq_file.h>
#include <asm/div64.h>
#include "ctree.h"
#include "extent_map.h"
@@ -6615,3 +6616,96 @@ void btrfs_update_commit_device_bytes_used(struct
btrfs_root *root,
}
unlock_chunks(root);
}
+
+
+void btrfs_print_devlist(struct seq_file *seq)
+{
+
+ /* Btrfs Procfs String Len */
+#define BPSL 256
+#define BTRFS_SEQ_PRINT(plist, arg)\
+ snprintf(str, BPSL, plist, arg);\
+ if (sprt)\
+ seq_printf(seq, "\t");\
+ seq_printf(seq, str)
+
+ char str[BPSL];
+ struct btrfs_device *device;
+ struct btrfs_fs_devices *fs_devices;
+ struct btrfs_fs_devices *cur_fs_devices;
+ struct btrfs_fs_devices *sprt; //sprout fs devices
+
+ seq_printf(seq, "\n#Its Experimental, parameters may change without
notice.\n\n");
+
+ mutex_lock(&uuid_mutex);
+ /* Todo: there must be better way than nested locks */
+ list_for_each_entry(cur_fs_devices, &fs_uuids, list) {
+
+ mutex_lock(&cur_fs_devices->device_list_mutex);
+
+ fs_devices = cur_fs_devices;
+ sprt = NULL;
+
+again_fs_devs:
+ if (sprt) {
+ BTRFS_SEQ_PRINT("[[seed_fsid: %pU]]\n",
fs_devices->fsid);
+ BTRFS_SEQ_PRINT("\tsprout_fsid:\t\t%pU\n", sprt->fsid);
+ } else {
+ BTRFS_SEQ_PRINT("[fsid: %pU]\n", fs_devices->fsid);
+ }
+ if (fs_devices->seed) {
+ BTRFS_SEQ_PRINT("\tseed_fsid:\t\t%pU\n",
fs_devices->seed->fsid);
+ }
+ BTRFS_SEQ_PRINT("\tnum_devices:\t\t%llu\n",
fs_devices->num_devices);
+ BTRFS_SEQ_PRINT("\topen_devices:\t\t%llu\n",
fs_devices->open_devices);
+ BTRFS_SEQ_PRINT("\trw_devices:\t\t%llu\n",
fs_devices->rw_devices);
+ BTRFS_SEQ_PRINT("\tmissing_devices:\t%llu\n",
fs_devices->missing_devices);
+ BTRFS_SEQ_PRINT("\ttotal_rw_devices:\t%llu\n",
fs_devices->total_rw_bytes);
+ BTRFS_SEQ_PRINT("\ttotal_devices:\t\t%llu\n",
fs_devices->total_devices);
+ BTRFS_SEQ_PRINT("\topened:\t\t\t%d\n", fs_devices->opened);
+ BTRFS_SEQ_PRINT("\tseeding:\t\t%d\n", fs_devices->seeding);
+ BTRFS_SEQ_PRINT("\trotating:\t\t%d\n", fs_devices->rotating);
+
+ list_for_each_entry(device, &fs_devices->devices, dev_list) {
+ BTRFS_SEQ_PRINT("\t[[uuid: %pU]]\n", device->uuid);
+ rcu_read_lock();
+ BTRFS_SEQ_PRINT("\t\tdevice:\t\t%s\n",
+ device->name ? rcu_str_deref(device->name):
"(null)");
+ rcu_read_unlock();
+ BTRFS_SEQ_PRINT("\t\tdevid:\t\t%llu\n", device->devid);
+ if (device->dev_root) {
+ BTRFS_SEQ_PRINT("\t\tdev_root_fsid:\t%pU\n",
+
device->dev_root->fs_info->fsid);
+ }
+ BTRFS_SEQ_PRINT("\t\tgeneration:\t%llu\n",
device->generation);
+ BTRFS_SEQ_PRINT("\t\ttotal_bytes:\t%llu\n",
device->total_bytes);
+ BTRFS_SEQ_PRINT("\t\tdev_totalbytes:\t%llu\n",
device->disk_total_bytes);
+ BTRFS_SEQ_PRINT("\t\tbytes_used:\t%llu\n",
device->bytes_used);
+ BTRFS_SEQ_PRINT("\t\ttype:\t\t%llu\n", device->type);
+ BTRFS_SEQ_PRINT("\t\tio_align:\t%u\n",
device->io_align);
+ BTRFS_SEQ_PRINT("\t\tio_width:\t%u\n",
device->io_width);
+ BTRFS_SEQ_PRINT("\t\tsector_size:\t%u\n",
device->sector_size);
+ BTRFS_SEQ_PRINT("\t\tmode:\t\t0x%llx\n",
(u64)device->mode);
+ BTRFS_SEQ_PRINT("\t\twriteable:\t%d\n",
device->writeable);
+ BTRFS_SEQ_PRINT("\t\tin_fs_metadata:\t%d\n",
device->in_fs_metadata);
+ BTRFS_SEQ_PRINT("\t\tmissing:\t%d\n", device->missing);
+ BTRFS_SEQ_PRINT("\t\tcan_discard:\t%d\n",
device->can_discard);
+ BTRFS_SEQ_PRINT("\t\treplace_tgtdev:\t%d\n",
+
device->is_tgtdev_for_dev_replace);
+ BTRFS_SEQ_PRINT("\t\tactive_pending:\t%d\n",
device->running_pending);
+ BTRFS_SEQ_PRINT("\t\tnobarriers:\t%d\n",
device->nobarriers);
+ BTRFS_SEQ_PRINT("\t\tdevstats_valid:\t%d\n",
device->dev_stats_valid);
+ BTRFS_SEQ_PRINT("\t\tbdev:\t\t%s\n", device->bdev ?
"not_null":"null");
+ }
+
+ if (fs_devices->seed) {
+ sprt = fs_devices;
+ fs_devices = fs_devices->seed;
+ goto again_fs_devs;
+ }
+ seq_printf(seq, "\n");
+
+ mutex_unlock(&cur_fs_devices->device_list_mutex);
+ }
+ mutex_unlock(&uuid_mutex);
+}
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 2b37da3..81f255e 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -510,4 +510,5 @@ static inline void btrfs_dev_stat_reset(struct btrfs_device
*dev,
void btrfs_update_commit_device_size(struct btrfs_fs_info *fs_info);
void btrfs_update_commit_device_bytes_used(struct btrfs_root *root,
struct btrfs_transaction *transaction);
+void btrfs_print_devlist(struct seq_file *seq);
#endif
--
2.0.0.153.g79dcccc
--
To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
