The patch titled
Subject: fsioctl.c: make generic_block_fiemap() signal-tolerant
has been removed from the -mm tree. Its filename was
fs-make-generic_block_fiemap-sig-tolerant.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
From: Dmitry Monakhov <dmonakhov@xxxxxxxxxx>
Subject: fsioctl.c: make generic_block_fiemap() signal-tolerant
__generic_block_fiemap may spin very long time for large sparse files.
Without this patch an unprivileged user may abuse system resources simply
by spawning a vast number of unkilable busyloops (works on ext2/ext3):
truncate --size 1T test
for ((i=0;i<1024;i++))
do
filefrag test > /dev/null &
done
Signed-off-by: Dmitry Monakhov <dmonakhov@xxxxxxxxxx>
Cc: Theodore Ts'o <tytso@xxxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Michael Kerrisk <mtk.manpages@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
Documentation/filesystems/fiemap.txt | 3 ++-
fs/ioctl.c | 5 +++++
2 files changed, 7 insertions(+), 1 deletion(-)
diff -puN Documentation/filesystems/fiemap.txt~fs-make-generic_block_fiemap-sig-tolerant Documentation/filesystems/fiemap.txt
--- a/Documentation/filesystems/fiemap.txt~fs-make-generic_block_fiemap-sig-tolerant
+++ a/Documentation/filesystems/fiemap.txt
@@ -196,7 +196,8 @@ struct fiemap_extent_info {
};
It is intended that the file system should not need to access any of this
-structure directly.
+structure directly. Filesystem handlers should be tolerant to signals and return
+EINTR once fatal signal received.
Flag checking should be done at the beginning of the ->fiemap callback via the
diff -puN fs/ioctl.c~fs-make-generic_block_fiemap-sig-tolerant fs/ioctl.c
--- a/fs/ioctl.c~fs-make-generic_block_fiemap-sig-tolerant
+++ a/fs/ioctl.c
@@ -379,6 +379,11 @@ int __generic_block_fiemap(struct inode
past_eof = true;
}
cond_resched();
+ if (fatal_signal_pending(current)) {
+ ret = -EINTR;
+ break;
+ }
+
} while (1);
/* If ret is 1 then we just hit the end of the extent array */
_
Patches currently in -mm which might be from dmonakhov@xxxxxxxxxx are
origin.patch
linux-next.patch
--
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
