From a311a08a4237241fb5b9d219d3e33346de6e83e0 Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Wed, 2 Oct 2024 08:02:13 -0700 Subject: [PATCH] iomap: constrain the file range passed to iomap_file_unshare File contents can only be shared (i.e. reflinked) below EOF, so it makes no sense to try to unshare ranges beyond EOF. Constrain the file range parameters here so that we don't have to do that in the callers. Fixes: 5f4e5752a8a3 ("fs: add iomap_file_dirty") Signed-off-by: Darrick J. Wong Link: https://lore.kernel.org/r/20241002150213.GC21853@frogsfrogsfrogs Reviewed-by: Christoph Hellwig Reviewed-by: Brian Foster Signed-off-by: Christian Brauner --- fs/dax.c | 6 +++++- fs/iomap/buffered-io.c | 6 +++++- 2 files changed, 10 insertions(+), 2 deletions(-) diff --git a/fs/dax.c b/fs/dax.c index becb4a6920c6a..c62acd2812f8d 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -1305,11 +1305,15 @@ int dax_file_unshare(struct inode *inode, loff_t pos, loff_t len, struct iomap_iter iter = { .inode = inode, .pos = pos, - .len = len, .flags = IOMAP_WRITE | IOMAP_UNSHARE | IOMAP_DAX, }; + loff_t size = i_size_read(inode); int ret; + if (pos < 0 || pos >= size) + return 0; + + iter.len = min(len, size - pos); while ((ret = iomap_iter(&iter, ops)) > 0) iter.processed = dax_unshare_iter(&iter); return ret; diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c index c1c559e0cc07c..78ebd265f4259 100644 --- a/fs/iomap/buffered-io.c +++ b/fs/iomap/buffered-io.c @@ -1375,11 +1375,15 @@ iomap_file_unshare(struct inode *inode, loff_t pos, loff_t len, struct iomap_iter iter = { .inode = inode, .pos = pos, - .len = len, .flags = IOMAP_WRITE | IOMAP_UNSHARE, }; + loff_t size = i_size_read(inode); int ret; + if (pos < 0 || pos >= size) + return 0; + + iter.len = min(len, size - pos); while ((ret = iomap_iter(&iter, ops)) > 0) iter.processed = iomap_unshare_iter(&iter); return ret; -- 2.49.0