From 66d78a11479cfea00e8d1d9d3e33f3db1597e6bf Mon Sep 17 00:00:00 2001 From: Brian Foster Date: Fri, 3 Oct 2025 09:46:41 -0400 Subject: [PATCH] xfs: error tag to force zeroing on debug kernels iomap_zero_range() has to cover various corner cases that are difficult to test on production kernels because it is used in fairly limited use cases. For example, it is currently only used by XFS and mostly only in partial block zeroing cases. While it's possible to test most of these functional cases, we can provide more robust test coverage by co-opting fallocate zero range to invoke zeroing of the entire range instead of the more efficient block punch/allocate sequence. Add an errortag to occasionally invoke forced zeroing. Signed-off-by: Brian Foster Reviewed-by: Christoph Hellwig Reviewed-by: Darrick J. Wong Signed-off-by: Christian Brauner --- fs/xfs/libxfs/xfs_errortag.h | 6 ++++-- fs/xfs/xfs_file.c | 29 ++++++++++++++++++++++------- 2 files changed, 26 insertions(+), 9 deletions(-) diff --git a/fs/xfs/libxfs/xfs_errortag.h b/fs/xfs/libxfs/xfs_errortag.h index de840abc0bcd4..57e47077c75a2 100644 --- a/fs/xfs/libxfs/xfs_errortag.h +++ b/fs/xfs/libxfs/xfs_errortag.h @@ -73,7 +73,8 @@ #define XFS_ERRTAG_WRITE_DELAY_MS 43 #define XFS_ERRTAG_EXCHMAPS_FINISH_ONE 44 #define XFS_ERRTAG_METAFILE_RESV_CRITICAL 45 -#define XFS_ERRTAG_MAX 46 +#define XFS_ERRTAG_FORCE_ZERO_RANGE 46 +#define XFS_ERRTAG_MAX 47 /* * Random factors for above tags, 1 means always, 2 means 1/2 time, etc. @@ -133,7 +134,8 @@ XFS_ERRTAG(ATTR_LEAF_TO_NODE, attr_leaf_to_node, 1) \ XFS_ERRTAG(WB_DELAY_MS, wb_delay_ms, 3000) \ XFS_ERRTAG(WRITE_DELAY_MS, write_delay_ms, 3000) \ XFS_ERRTAG(EXCHMAPS_FINISH_ONE, exchmaps_finish_one, 1) \ -XFS_ERRTAG(METAFILE_RESV_CRITICAL, metafile_resv_crit, 4) +XFS_ERRTAG(METAFILE_RESV_CRITICAL, metafile_resv_crit, 4) \ +XFS_ERRTAG(FORCE_ZERO_RANGE, force_zero_range, 4) #endif /* XFS_ERRTAG */ #endif /* __XFS_ERRORTAG_H_ */ diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c index 2702fef2c90cd..5b9864c8582e5 100644 --- a/fs/xfs/xfs_file.c +++ b/fs/xfs/xfs_file.c @@ -27,6 +27,8 @@ #include "xfs_file.h" #include "xfs_aops.h" #include "xfs_zone_alloc.h" +#include "xfs_error.h" +#include "xfs_errortag.h" #include #include @@ -1254,23 +1256,36 @@ xfs_falloc_zero_range( struct xfs_zone_alloc_ctx *ac) { struct inode *inode = file_inode(file); + struct xfs_inode *ip = XFS_I(inode); unsigned int blksize = i_blocksize(inode); loff_t new_size = 0; int error; - trace_xfs_zero_file_space(XFS_I(inode)); + trace_xfs_zero_file_space(ip); error = xfs_falloc_newsize(file, mode, offset, len, &new_size); if (error) return error; - error = xfs_free_file_space(XFS_I(inode), offset, len, ac); - if (error) - return error; + /* + * Zero range implements a full zeroing mechanism but is only used in + * limited situations. It is more efficient to allocate unwritten + * extents than to perform zeroing here, so use an errortag to randomly + * force zeroing on DEBUG kernels for added test coverage. + */ + if (XFS_TEST_ERROR(ip->i_mount, + XFS_ERRTAG_FORCE_ZERO_RANGE)) { + error = xfs_zero_range(ip, offset, len, ac, NULL); + } else { + error = xfs_free_file_space(ip, offset, len, ac); + if (error) + return error; - len = round_up(offset + len, blksize) - round_down(offset, blksize); - offset = round_down(offset, blksize); - error = xfs_alloc_file_space(XFS_I(inode), offset, len); + len = round_up(offset + len, blksize) - + round_down(offset, blksize); + offset = round_down(offset, blksize); + error = xfs_alloc_file_space(ip, offset, len); + } if (error) return error; return xfs_falloc_setsize(file, new_size); -- 2.47.3