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| author |   Theodore Ts'o <tytso@mit.edu> | 2016-03-30 22:36:24 -0400 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2016-03-30 22:36:24 -0400 |
| commit | 1028b55bafb7611dda1d8fed2aeca16a436b7dff (patch) | |
| tree | c6881992855b87775897afe3712e6c72811856a0 /fs | |
| parent | btrfs: fix crash/invalid memory access on fsync when using overlayfs (diff) | |
| download | linux-dev-1028b55bafb7611dda1d8fed2aeca16a436b7dff.tar.xz linux-dev-1028b55bafb7611dda1d8fed2aeca16a436b7dff.zip | |
ext4: allow readdir()'s of large empty directories to be interrupted
If a directory has a large number of empty blocks, iterating over all
of them can take a long time, leading to scheduler warnings and users
getting irritated when they can't kill a process in the middle of one
of these long-running readdir operations. Fix this by adding checks to
ext4_readdir() and ext4_htree_fill_tree().
Reported-by: Benjamin LaHaise <bcrl@kvack.org>
Google-Bug-Id: 27880676
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/ext4/dir.c | 5 | ||||
| -rw-r--r-- | fs/ext4/namei.c | 5 |
2 files changed, 10 insertions, 0 deletions
diff --git a/fs/ext4/dir.c b/fs/ext4/dir.c index 33f5e2a50cf8..ebfcb8999db2 100644 --- a/fs/ext4/dir.c +++ b/fs/ext4/dir.c @@ -150,6 +150,11 @@ static int ext4_readdir(struct file *file, struct dir_context *ctx) while (ctx->pos < inode->i_size) { struct ext4_map_blocks map; + if (fatal_signal_pending(current)) { + err = -ERESTARTSYS; + goto errout; + } + cond_resched(); map.m_lblk = ctx->pos >> EXT4_BLOCK_SIZE_BITS(sb); map.m_len = 1; err = ext4_map_blocks(NULL, inode, &map, 0); diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c index 48e4b8907826..db98f89f737f 100644 --- a/fs/ext4/namei.c +++ b/fs/ext4/namei.c @@ -1107,6 +1107,11 @@ int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash, } while (1) { + if (signal_pending(current)) { + err = -ERESTARTSYS; + goto errout; + } + cond_resched(); block = dx_get_block(frame->at); ret = htree_dirblock_to_tree(dir_file, dir, block, &hinfo, start_hash, start_minor_hash); |