From 210549ebe9047ae5a8cc47487203d3ee16a7749b Mon Sep 17 00:00:00 2001 From: David Sterba Date: Sat, 9 Feb 2013 23:38:06 +0000 Subject: [PATCH] btrfs: add cancellation points to defrag The defrag operation can take very long, we want to have a way how to cancel it. The code checks for a pending signal at safe points in the defrag loops and returns EAGAIN. This means a user can press ^C after running 'btrfs fi defrag', woks for both defrag modes, files and root. Returning from the command was instant in my light tests, but may take longer depending on the aging factor of the filesystem. Signed-off-by: David Sterba Signed-off-by: Josef Bacik --- fs/btrfs/ctree.h | 7 +++++++ fs/btrfs/ioctl.c | 6 ++++++ fs/btrfs/transaction.c | 6 ++++++ 3 files changed, 19 insertions(+) diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index f1cc247f3178..14f01dc70ea6 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -3786,4 +3786,11 @@ static inline int is_fstree(u64 rootid) return 1; return 0; } + +static inline int btrfs_defrag_cancelled(struct btrfs_fs_info *fs_info) +{ + return signal_pending(current); +} + + #endif diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 6d6314406e27..d02ec577f70f 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -1202,6 +1202,12 @@ int btrfs_defrag_file(struct inode *inode, struct file *file, if (!(inode->i_sb->s_flags & MS_ACTIVE)) break; + if (btrfs_defrag_cancelled(root->fs_info)) { + printk(KERN_DEBUG "btrfs: defrag_file cancelled\n"); + ret = -EAGAIN; + break; + } + if (!should_defrag_range(inode, (u64)i << PAGE_CACHE_SHIFT, extent_thresh, &last_len, &skip, &defrag_end, range->flags & diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c index 60481a53e004..d574d830a1c4 100644 --- a/fs/btrfs/transaction.c +++ b/fs/btrfs/transaction.c @@ -984,6 +984,12 @@ int btrfs_defrag_root(struct btrfs_root *root) if (btrfs_fs_closing(root->fs_info) || ret != -EAGAIN) break; + + if (btrfs_defrag_cancelled(root->fs_info)) { + printk(KERN_DEBUG "btrfs: defrag_root cancelled\n"); + ret = -EAGAIN; + break; + } } root->defrag_running = 0; return ret; -- 2.20.1