From 0d0104adc2c8316433b660cdf6d182a09881864f Mon Sep 17 00:00:00 2001 From: Andrea Parri Date: Mon, 28 Sep 2026 10:48:08 +0200 Subject: [PATCH] iomap: don't lose a fiemap iteration error when emitting the last extent iomap_fiemap() emits extents one behind: iomap_fiemap_iter() flushes the previous extent and remembers the current one, and the remembered extent is written with FIEMAP_EXTENT_LAST after the iteration loop. That final flush overwrites ret, so when ->iomap_begin() fails partway through the iteration the error is replaced by the result of iomap_to_fiemap() (zero on success) and iomap_fiemap() returns success with a truncated extent list whose last entry is wrongly marked as the last extent in the file. The pre-iomap_iter code returned the error from inside the loop, before flushing the pending extent. Check for the iteration error before flushing the pending extent, so that real errors are propagated and only a successful iteration emits the final FIEMAP_EXTENT_LAST extent. -ENOENT (no mapping) is still not an error, and the pending extent is still emitted in that case. Fixes: 7892386d3571 ("iomap: switch iomap_fiemap to use iomap_iter") Cc: stable@vger.kernel.org # v5.15 Reviewed-by: Brian Foster Reviewed-by: Darrick J. Wong Reviewed-by: Christoph Hellwig Signed-off-by: Andrea Parri Link: https://patch.msgid.link/250226e33b3b23c6b1714a45dc3c465c2a45cdc0.1790342457.git.parri.andrea@gmail.com Reviewed-by: "Darrick J. Wong" Signed-off-by: Christian Brauner (Amutable) --- fs/iomap/fiemap.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/fs/iomap/fiemap.c b/fs/iomap/fiemap.c index d11dadff8286..54b824b7edb5 100644 --- a/fs/iomap/fiemap.c +++ b/fs/iomap/fiemap.c @@ -76,15 +76,15 @@ int iomap_fiemap(struct inode *inode, struct fiemap_extent_info *fi, while ((ret = iomap_iter(&iter, ops)) > 0) iter.status = iomap_fiemap_iter(&iter, fi, &prev); + /* inode with no (attribute) mapping will give ENOENT */ + if (ret < 0 && ret != -ENOENT) + return ret; + if (prev.type != IOMAP_HOLE) { ret = iomap_to_fiemap(fi, &prev, FIEMAP_EXTENT_LAST); if (ret < 0) return ret; } - - /* inode with no (attribute) mapping will give ENOENT */ - if (ret < 0 && ret != -ENOENT) - return ret; return 0; } EXPORT_SYMBOL_GPL(iomap_fiemap);