| Message ID | 20180424050313.32740-1-wqu@suse.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, Apr 24, 2018 at 01:03:13PM +0800, Qu Wenruo wrote: > It's pretty handy if we can get debug output for locking status of an > extent buffer, specially for race related debugging. > > So add the following output for btrfs_print_tree() and > btrfs_print_leaf(): > - refs > - write_locks (as w:%d) > - read_locks (as r:%d) > - blocking_writers (as bw:%d) > - blocking_readers (as br:%d) > - spinning_writers (as sw:%d) > - spinning_readers (as sr:%d) > - lock_owner > - current->pid This is fine > + btrfs_info(eb->fs_info, I'd rather make that btrfs_debug, but info is fine as long as it's under CONFIG_BTRFS_DEBUG. > +"refs %u lock(w:%u r:%u bw:%u br:%u sw:%u sr:%u) lock_owner %u current %u", This is not :) but I'll fix that according to the above. Reviewed-by: David Sterba <dsterba@suse.com> -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 2018年04月24日 22:44, David Sterba wrote: > On Tue, Apr 24, 2018 at 01:03:13PM +0800, Qu Wenruo wrote: >> It's pretty handy if we can get debug output for locking status of an >> extent buffer, specially for race related debugging. >> >> So add the following output for btrfs_print_tree() and >> btrfs_print_leaf(): >> - refs >> - write_locks (as w:%d) >> - read_locks (as r:%d) >> - blocking_writers (as bw:%d) >> - blocking_readers (as br:%d) >> - spinning_writers (as sw:%d) >> - spinning_readers (as sr:%d) >> - lock_owner >> - current->pid > > This is fine > >> + btrfs_info(eb->fs_info, > > I'd rather make that btrfs_debug, but info is fine as long as it's under > CONFIG_BTRFS_DEBUG. > >> +"refs %u lock(w:%u r:%u bw:%u br:%u sw:%u sr:%u) lock_owner %u current %u", > > This is not :) but I'll fix that according to the above. Not again... I forgot to commit the change, no wonder everything is the same and need to modify the patch commit message. Sorry for the inconvenience. Thanks, Qu > > Reviewed-by: David Sterba <dsterba@suse.com> > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >
diff --git a/fs/btrfs/print-tree.c b/fs/btrfs/print-tree.c index 9904cf741e1c..7f0ada51e5fe 100644 --- a/fs/btrfs/print-tree.c +++ b/fs/btrfs/print-tree.c @@ -179,6 +179,26 @@ static void print_uuid_item(struct extent_buffer *l, unsigned long offset, } } +/* + * Helper to output refs and locking status. + * + * Useful to debug race related problem + */ +static void print_eb_refs_lock(struct extent_buffer *eb) +{ +#ifdef CONFIG_BTRFS_DEBUG + btrfs_info(eb->fs_info, +"refs %u lock(w:%u r:%u bw:%u br:%u sw:%u sr:%u) lock_owner %u current %u", + atomic_read(&eb->refs), atomic_read(&eb->write_locks), + atomic_read(&eb->read_locks), + atomic_read(&eb->blocking_writers), + atomic_read(&eb->blocking_readers), + atomic_read(&eb->spinning_writers), + atomic_read(&eb->spinning_readers), + eb->lock_owner, current->pid); +#endif +} + void btrfs_print_leaf(struct extent_buffer *l) { struct btrfs_fs_info *fs_info; @@ -206,6 +226,7 @@ void btrfs_print_leaf(struct extent_buffer *l) "leaf %llu gen %llu total ptrs %d free space %d owner %llu", btrfs_header_bytenr(l), btrfs_header_generation(l), nr, btrfs_leaf_free_space(fs_info, l), btrfs_header_owner(l)); + print_eb_refs_lock(l); for (i = 0 ; i < nr ; i++) { item = btrfs_item_nr(i); btrfs_item_key_to_cpu(l, &key, i); @@ -360,6 +381,7 @@ void btrfs_print_tree(struct extent_buffer *c, bool follow) btrfs_header_bytenr(c), level, btrfs_header_generation(c), nr, (u32)BTRFS_NODEPTRS_PER_BLOCK(fs_info) - nr, btrfs_header_owner(c)); + print_eb_refs_lock(c); for (i = 0; i < nr; i++) { btrfs_node_key_to_cpu(c, &key, i); pr_info("\tkey %d (%llu %u %llu) block %llu gen %llu\n",
It's pretty handy if we can get debug output for locking status of an extent buffer, specially for race related debugging. So add the following output for btrfs_print_tree() and btrfs_print_leaf(): - refs - write_locks (as w:%d) - read_locks (as r:%d) - blocking_writers (as bw:%d) - blocking_readers (as br:%d) - spinning_writers (as sw:%d) - spinning_readers (as sr:%d) - lock_owner - current->pid Signed-off-by: Qu Wenruo <wqu@suse.com> --- changelog: v2: Use correct specifier for int (both atomic_t and pid_t, no special specifier found in Documentation/core-api/printk-formats.rst) --- fs/btrfs/print-tree.c | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+)