This is an automated email from the ASF dual-hosted git repository.
acassis pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/nuttx.git
The following commit(s) were added to refs/heads/master by this push:
new 5047285b6b3 fs/fat: Keep the last cluster of a file on a write past
EOF.
5047285b6b3 is described below
commit 5047285b6b3a18949eae7f5dd64ffce422c740c0
Author: Marco Casaroli <[email protected]>
AuthorDate: Wed Nov 4 22:34:37 2026 +0100
fs/fat: Keep the last cluster of a file on a write past EOF.
A write past EOF on a file whose size is a multiple of the cluster size
zeroes the last cluster of the file. fat_get_sectors() zeroes the gap in
that cluster from "s_size & (clu_size - 1)", which is 0 when the size is
on a cluster boundary. This cluster is full of file data and has no gap.
Skip area (1) at a cluster boundary. The gap then starts in the next
cluster, and areas (2) and (3) already zero it, as for an empty file.
Assisted-by: Claude Code:claude-opus-5-5
Signed-off-by: Marco Casaroli <[email protected]>
---
fs/fat/fs_fat32.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/fs/fat/fs_fat32.c b/fs/fat/fs_fat32.c
index 2eed2411f17..2cd168edf76 100644
--- a/fs/fat/fs_fat32.c
+++ b/fs/fat/fs_fat32.c
@@ -1034,10 +1034,10 @@ static int fat_get_sectors(FAR struct file *filep, bool
read)
* s_size f_pos
*/
- /* zero area (1) */
+ /* zero area (1): there is none if s_size is on a cluster boundary */
if (i == num_clu && filep->f_pos > shared->s_size &&
- shared->s_size != 0)
+ (shared->s_size & (clu_size - 1)) != 0)
{
zero_start = ff->ff_shared->s_size & (clu_size - 1);
