From 1abe9b8a138c9988ba8f7bfded6453649a31541f Mon Sep 17 00:00:00 2001 From: liubo Date: Thu, 24 Mar 2011 11:18:59 +0000 Subject: Btrfs: add initial tracepoint support for btrfs Tracepoints can provide insight into why btrfs hits bugs and be greatly helpful for debugging, e.g dd-7822 [000] 2121.641088: btrfs_inode_request: root = 5(FS_TREE), gen = 4, ino = 256, blocks = 8, disk_i_size = 0, last_trans = 8, logged_trans = 0 dd-7822 [000] 2121.641100: btrfs_inode_new: root = 5(FS_TREE), gen = 8, ino = 257, blocks = 0, disk_i_size = 0, last_trans = 0, logged_trans = 0 btrfs-transacti-7804 [001] 2146.935420: btrfs_cow_block: root = 2(EXTENT_TREE), refs = 2, orig_buf = 29368320 (orig_level = 0), cow_buf = 29388800 (cow_level = 0) btrfs-transacti-7804 [001] 2146.935473: btrfs_cow_block: root = 1(ROOT_TREE), refs = 2, orig_buf = 29364224 (orig_level = 0), cow_buf = 29392896 (cow_level = 0) btrfs-transacti-7804 [001] 2146.972221: btrfs_transaction_commit: root = 1(ROOT_TREE), gen = 8 flush-btrfs-2-7821 [001] 2155.824210: btrfs_chunk_alloc: root = 3(CHUNK_TREE), offset = 1103101952, size = 1073741824, num_stripes = 1, sub_stripes = 0, type = DATA flush-btrfs-2-7821 [001] 2155.824241: btrfs_cow_block: root = 2(EXTENT_TREE), refs = 2, orig_buf = 29388800 (orig_level = 0), cow_buf = 29396992 (cow_level = 0) flush-btrfs-2-7821 [001] 2155.824255: btrfs_cow_block: root = 4(DEV_TREE), refs = 2, orig_buf = 29372416 (orig_level = 0), cow_buf = 29401088 (cow_level = 0) flush-btrfs-2-7821 [000] 2155.824329: btrfs_cow_block: root = 3(CHUNK_TREE), refs = 2, orig_buf = 20971520 (orig_level = 0), cow_buf = 20975616 (cow_level = 0) btrfs-endio-wri-7800 [001] 2155.898019: btrfs_cow_block: root = 5(FS_TREE), refs = 2, orig_buf = 29384704 (orig_level = 0), cow_buf = 29405184 (cow_level = 0) btrfs-endio-wri-7800 [001] 2155.898043: btrfs_cow_block: root = 7(CSUM_TREE), refs = 2, orig_buf = 29376512 (orig_level = 0), cow_buf = 29409280 (cow_level = 0) Here is what I have added: 1) ordere_extent: btrfs_ordered_extent_add btrfs_ordered_extent_remove btrfs_ordered_extent_start btrfs_ordered_extent_put These provide critical information to understand how ordered_extents are updated. 2) extent_map: btrfs_get_extent extent_map is used in both read and write cases, and it is useful for tracking how btrfs specific IO is running. 3) writepage: __extent_writepage btrfs_writepage_end_io_hook Pages are cirtical resourses and produce a lot of corner cases during writeback, so it is valuable to know how page is written to disk. 4) inode: btrfs_inode_new btrfs_inode_request btrfs_inode_evict These can show where and when a inode is created, when a inode is evicted. 5) sync: btrfs_sync_file btrfs_sync_fs These show sync arguments. 6) transaction: btrfs_transaction_commit In transaction based filesystem, it will be useful to know the generation and who does commit. 7) back reference and cow: btrfs_delayed_tree_ref btrfs_delayed_data_ref btrfs_delayed_ref_head btrfs_cow_block Btrfs natively supports back references, these tracepoints are helpful on understanding btrfs's COW mechanism. 8) chunk: btrfs_chunk_alloc btrfs_chunk_free Chunk is a link between physical offset and logical offset, and stands for space infomation in btrfs, and these are helpful on tracing space things. 9) reserved_extent: btrfs_reserved_extent_alloc btrfs_reserved_extent_free These can show how btrfs uses its space. Signed-off-by: Liu Bo Signed-off-by: Chris Mason --- fs/btrfs/super.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'fs/btrfs/super.c') diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c index d39a9895d93..2edfc039f09 100644 --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -52,6 +52,9 @@ #include "export.h" #include "compression.h" +#define CREATE_TRACE_POINTS +#include + static const struct super_operations btrfs_super_ops; static const char *btrfs_decode_error(struct btrfs_fs_info *fs_info, int errno, @@ -620,6 +623,8 @@ int btrfs_sync_fs(struct super_block *sb, int wait) struct btrfs_root *root = btrfs_sb(sb); int ret; + trace_btrfs_sync_fs(wait); + if (!wait) { filemap_flush(root->fs_info->btree_inode->i_mapping); return 0; -- cgit v1.2.3-70-g09d2 From 200da64e0b039f873f0f20481e6a7d056e7cc6c9 Mon Sep 17 00:00:00 2001 From: Tsutomu Itoh Date: Thu, 31 Mar 2011 00:44:29 +0000 Subject: Btrfs: fix /proc/mounts info. Some mount options are not displayed by /proc/mounts. This patch displays the option such as compress_type by /proc/mounts. Ex. [before] $ mount | grep sdc2 /dev/sdc2 on /test12 type btrfs (rw,space_cache,compress=lzo) $ cat /proc/mounts | grep sdc2 /dev/sdc2 /test12 btrfs rw,relatime,compress 0 0 [after] $ mount | grep sdc2 /dev/sdc2 on /test12 type btrfs (rw,space_cache,compress=lzo) $ cat /proc/mounts | grep sdc2 /dev/sdc2 /test12 btrfs rw,relatime,compress=lzo,space_cache 0 0 Signed-off-by: Tsutomu Itoh Signed-off-by: Chris Mason --- fs/btrfs/super.c | 19 +++++++++++++++++-- 1 file changed, 17 insertions(+), 2 deletions(-) (limited to 'fs/btrfs/super.c') diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c index 2edfc039f09..58e7de9cc90 100644 --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -644,6 +644,7 @@ static int btrfs_show_options(struct seq_file *seq, struct vfsmount *vfs) { struct btrfs_root *root = btrfs_sb(vfs->mnt_sb); struct btrfs_fs_info *info = root->fs_info; + char *compress_type; if (btrfs_test_opt(root, DEGRADED)) seq_puts(seq, ",degraded"); @@ -662,8 +663,16 @@ static int btrfs_show_options(struct seq_file *seq, struct vfsmount *vfs) if (info->thread_pool_size != min_t(unsigned long, num_online_cpus() + 2, 8)) seq_printf(seq, ",thread_pool=%d", info->thread_pool_size); - if (btrfs_test_opt(root, COMPRESS)) - seq_puts(seq, ",compress"); + if (btrfs_test_opt(root, COMPRESS)) { + if (info->compress_type == BTRFS_COMPRESS_ZLIB) + compress_type = "zlib"; + else + compress_type = "lzo"; + if (btrfs_test_opt(root, FORCE_COMPRESS)) + seq_printf(seq, ",compress-force=%s", compress_type); + else + seq_printf(seq, ",compress=%s", compress_type); + } if (btrfs_test_opt(root, NOSSD)) seq_puts(seq, ",nossd"); if (btrfs_test_opt(root, SSD_SPREAD)) @@ -678,6 +687,12 @@ static int btrfs_show_options(struct seq_file *seq, struct vfsmount *vfs) seq_puts(seq, ",discard"); if (!(root->fs_info->sb->s_flags & MS_POSIXACL)) seq_puts(seq, ",noacl"); + if (btrfs_test_opt(root, SPACE_CACHE)) + seq_puts(seq, ",space_cache"); + if (btrfs_test_opt(root, CLEAR_CACHE)) + seq_puts(seq, ",clear_cache"); + if (btrfs_test_opt(root, USER_SUBVOL_RM_ALLOWED)) + seq_puts(seq, ",user_subvol_rm_allowed"); return 0; } -- cgit v1.2.3-70-g09d2 From e15d0542426f063dc53b4c51bdfc11e0bbe4d298 Mon Sep 17 00:00:00 2001 From: Xin Zhong Date: Wed, 6 Apr 2011 07:33:51 +0000 Subject: Btrfs: fix subvolume mount by name problem when default mount subvolume is set 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 Signed-off-by: Chris Mason --- fs/btrfs/super.c | 42 +++++++++++++++++++++++++++++++++--------- 1 file changed, 33 insertions(+), 9 deletions(-) (limited to 'fs/btrfs/super.c') diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c index 58e7de9cc90..0ac712efcdf 100644 --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -159,7 +159,7 @@ 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 = { @@ -189,6 +189,7 @@ 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}, }; @@ -232,6 +233,7 @@ 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 @@ -388,7 +390,7 @@ 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; @@ -429,6 +431,18 @@ 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); @@ -736,6 +750,7 @@ static struct dentry *btrfs_mount(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)) @@ -743,7 +758,7 @@ static struct dentry *btrfs_mount(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 ERR_PTR(error); @@ -807,15 +822,17 @@ static struct dentry *btrfs_mount(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)); @@ -836,6 +853,13 @@ static struct dentry *btrfs_mount(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; + } } kfree(subvol_name); -- cgit v1.2.3-70-g09d2