From 46c92a4aedd910262fb920064b59fd29ab27b377 Mon Sep 17 00:00:00 2001 From: David Sterba Date: Wed, 5 Feb 2014 15:26:17 +0100 Subject: [PATCH] btrfs: add support for processing pending changes There are some actions that modify global filesystem state but cannot be performed at the time of request, but later at the transaction commit time when the filesystem is in a known state. For example enabling new incompat features on-the-fly or issuing transaction commit from unsafe contexts (sysfs handlers). Signed-off-by: David Sterba (cherry picked from commit 572d9ab7845ea0e043ec34cd733a75228130ad03) --- fs/btrfs/ctree.h | 45 ++++++++++++++++++++++++++++++++++++++++++ fs/btrfs/disk-io.c | 6 ++++++ fs/btrfs/transaction.c | 16 +++++++++++++++ fs/btrfs/transaction.h | 2 ++ 4 files changed, 69 insertions(+) diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index fe69edda11fba..f30b061ef77d0 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -1402,6 +1402,11 @@ struct btrfs_fs_info { */ u64 last_trans_log_full_commit; unsigned long mount_opt; + /* + * Track requests for actions that need to be done during transaction + * commit (like for some mount options). + */ + unsigned long pending_changes; unsigned long compress_type:4; int commit_interval; /* @@ -2103,6 +2108,7 @@ struct btrfs_ioctl_defrag_range_args { #define btrfs_raw_test_opt(o, opt) ((o) & BTRFS_MOUNT_##opt) #define btrfs_test_opt(root, opt) ((root)->fs_info->mount_opt & \ BTRFS_MOUNT_##opt) + #define btrfs_set_and_info(root, opt, fmt, args...) \ { \ if (!btrfs_test_opt(root, opt)) \ @@ -2117,6 +2123,45 @@ struct btrfs_ioctl_defrag_range_args { btrfs_clear_opt(root->fs_info->mount_opt, opt); \ } +/* + * Requests for changes that need to be done during transaction commit. + * + * Internal mount options that are used for special handling of the real + * mount options (eg. cannot be set during remount and have to be set during + * transaction commit) + */ + +#define btrfs_test_pending(info, opt) \ + test_bit(BTRFS_PENDING_##opt, &(info)->pending_changes) +#define btrfs_set_pending(info, opt) \ + set_bit(BTRFS_PENDING_##opt, &(info)->pending_changes) +#define btrfs_clear_pending(info, opt) \ + clear_bit(BTRFS_PENDING_##opt, &(info)->pending_changes) + +/* + * Helpers for setting pending mount option changes. + * + * Expects corresponding macros + * BTRFS_PENDING_SET_ and CLEAR_ + short mount option name + */ +#define btrfs_set_pending_and_info(info, opt, fmt, args...) \ +do { \ + if (!btrfs_raw_test_opt((info)->mount_opt, opt)) { \ + btrfs_info((info), fmt, ##args); \ + btrfs_set_pending((info), SET_##opt); \ + btrfs_clear_pending((info), CLEAR_##opt); \ + } \ +} while(0) + +#define btrfs_clear_pending_and_info(info, opt, fmt, args...) \ +do { \ + if (btrfs_raw_test_opt((info)->mount_opt, opt)) { \ + btrfs_info((info), fmt, ##args); \ + btrfs_set_pending((info), CLEAR_##opt); \ + btrfs_clear_pending((info), SET_##opt); \ + } \ +} while(0) + /* * Inode flags */ diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 97676731190c1..1885bc3c80df0 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -2834,6 +2834,12 @@ retry_root_backup: if (btrfs_test_opt(tree_root, CHANGE_INODE_CACHE)) btrfs_set_opt(tree_root->fs_info->mount_opt, INODE_MAP_CACHE); + /* + * Mount does not set all options immediatelly, we can do it now and do + * not have to wait for transaction commit + */ + btrfs_apply_pending_changes(fs_info); + #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY if (btrfs_test_opt(tree_root, CHECK_INTEGRITY)) { ret = btrfsic_mount(tree_root, fs_devices, diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c index 63c6d05950f24..be825b67eaa62 100644 --- a/fs/btrfs/transaction.c +++ b/fs/btrfs/transaction.c @@ -1883,6 +1883,8 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans, else btrfs_clear_opt(root->fs_info->mount_opt, INODE_MAP_CACHE); + btrfs_apply_pending_changes(root->fs_info); + /* commit_fs_roots gets rid of all the tree log roots, it is now * safe to free the root of tree log roots */ @@ -2052,3 +2054,17 @@ int btrfs_clean_one_deleted_snapshot(struct btrfs_root *root) return (ret < 0) ? 0 : 1; } + +void btrfs_apply_pending_changes(struct btrfs_fs_info *fs_info) +{ + unsigned long prev; + unsigned long bit; + + prev = cmpxchg(&fs_info->pending_changes, 0, 0); + if (!prev) + return; + + if (prev) + btrfs_warn(fs_info, + "unknown pending changes left 0x%lx, ignoring", prev); +} diff --git a/fs/btrfs/transaction.h b/fs/btrfs/transaction.h index 1ba9c3e041914..c3b1f1f60263b 100644 --- a/fs/btrfs/transaction.h +++ b/fs/btrfs/transaction.h @@ -172,4 +172,6 @@ int btrfs_wait_marked_extents(struct btrfs_root *root, int btrfs_transaction_blocked(struct btrfs_fs_info *info); int btrfs_transaction_in_commit(struct btrfs_fs_info *info); void btrfs_put_transaction(struct btrfs_transaction *transaction); +void btrfs_apply_pending_changes(struct btrfs_fs_info *fs_info); + #endif -- 2.53.0