From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A058B2D9EEA; Wed, 29 Oct 2025 01:14:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761700497; cv=none; b=EXXF5CHpT1aOXcSVuNnrXDSEyx9AwaWEzAXoQojVvGn52D5swVxSIDT1yRLrkiywPmhu+jvouhCowemNT9YTuY6CrtcDSdZJKRKbf5VCD6trwO4JWg1MGMDCWGHTuU/DNMLnmclApl2EEGhg35EveY+JWV3r+ypKnhAHjbluyhs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761700497; c=relaxed/simple; bh=sMf6D2z633UWR6vZ9TBo2dC0KXCJ9+QLWwDc8Hqbd64=; h=Date:Subject:From:To:Cc:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=Qn2fkjP2KFoZSlWJOCPH/lxWQfoT0WM6cHnDo+/Dl9sy8bDBBAvOTJ3+tq/BEficmDTbONDgCkbIjP1cluKsa3KT5UZjCTGHIssTrc2Io34d5B/iZh+MVOCVA2kWkI0pUHigAiN8takmNDrE2RPjsb1Xai47+5CVgtAAy+sJaP0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=WuoVuQ+U; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="WuoVuQ+U" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 72096C4CEE7; Wed, 29 Oct 2025 01:14:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1761700497; bh=sMf6D2z633UWR6vZ9TBo2dC0KXCJ9+QLWwDc8Hqbd64=; h=Date:Subject:From:To:Cc:In-Reply-To:References:From; b=WuoVuQ+UNn7LmVK9vwwDkYo6BveyT2JPqs0GGPGaQaL+n2KzGDewBUH2iwFxanMtY ZXOmlApe5Z/Xbdm9KsfQZ6T/mUY87XgAVwzO0bpeABfLN42CHHNMbql0ZFbv//mUpw MYu0/2YQL/Ox08BOS6qVzVKE5dC2Pz7s1K5bVqRPa7+J5odT42cx0CE0MX54BA2e9m BHTAXEfASnwa913rHbpbCAB2bTcf/9wZnYJK0GcDfiMlN7W1ih+Lkn4NK8cxD/3X9Y MUxhSiCHHWdYd6V2ejTvWWCN4QbkporBHEqakXGW327X/QZTZR1bX98HTJ6MPaifyP XYfMHRrV4oUOA== Date: Tue, 28 Oct 2025 18:14:57 -0700 Subject: [PATCH 06/11] fuse2fs: use coarse timestamps for iomap mode From: "Darrick J. Wong" To: tytso@mit.edu Cc: linux-fsdevel@vger.kernel.org, joannelkoong@gmail.com, bernd@bsbernd.com, neal@gompa.dev, miklos@szeredi.hu, linux-ext4@vger.kernel.org Message-ID: <176169818331.1430380.10138568938764887209.stgit@frogsfrogsfrogs> In-Reply-To: <176169818170.1430380.13590456647130347042.stgit@frogsfrogsfrogs> References: <176169818170.1430380.13590456647130347042.stgit@frogsfrogsfrogs> Precedence: bulk X-Mailing-List: linux-ext4@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit From: Darrick J. Wong In iomap mode, the kernel is responsible for maintaining timestamps because file writes don't upcall to fuse2fs. The kernel's predicate for deciding if [cm]time should be updated bases its decisions off [cm]time being an exact match for the coarse clock (instead of checking that [cm]time < coarse_clock) which means that fuse2fs setting a fine-grained timestamp that is slightly ahead of the coarse clock can result in timestamps appearing to go backwards. generic/423 doesn't like seeing btime > ctime from statx, so we'll use the coarse clock in iomap mode. Signed-off-by: "Darrick J. Wong" --- fuse4fs/fuse4fs.c | 110 +++++++++++++++++++++++++++++++---------------------- misc/fuse2fs.c | 34 ++++++++++++---- 2 files changed, 90 insertions(+), 54 deletions(-) diff --git a/fuse4fs/fuse4fs.c b/fuse4fs/fuse4fs.c index 7570950ca2458d..cafee29991bff6 100644 --- a/fuse4fs/fuse4fs.c +++ b/fuse4fs/fuse4fs.c @@ -1004,8 +1004,24 @@ static inline void fuse4fs_dump_extents(struct fuse4fs *ff, ext2_ino_t ino, ext2fs_extent_free(extents); } -static void get_now(struct timespec *now) +static void fuse4fs_get_now(struct fuse4fs *ff, struct timespec *now) { +#ifdef CLOCK_REALTIME_COARSE + /* + * In iomap mode, the kernel is responsible for maintaining timestamps + * because file writes don't upcall to fuse4fs. The kernel's predicate + * for deciding if [cm]time should be updated bases its decisions off + * [cm]time being an exact match for the coarse clock (instead of + * checking that [cm]time < coarse_clock) which means that fuse4fs + * setting a fine-grained timestamp that is slightly ahead of the + * coarse clock can result in timestamps appearing to go backwards. + * generic/423 doesn't like seeing btime > ctime from statx, so we'll + * use the coarse clock in iomap mode. + */ + if (fuse4fs_iomap_enabled(ff) && + !clock_gettime(CLOCK_REALTIME_COARSE, now)) + return; +#endif #ifdef CLOCK_REALTIME if (!clock_gettime(CLOCK_REALTIME, now)) return; @@ -1028,11 +1044,12 @@ static void increment_version(struct ext2_inode_large *inode) inode->i_version_hi = ver >> 32; } -static void init_times(struct ext2_inode_large *inode) +static void fuse4fs_init_timestamps(struct fuse4fs *ff, + struct ext2_inode_large *inode) { struct timespec now; - get_now(&now); + fuse4fs_get_now(ff, &now); EXT4_INODE_SET_XTIME(i_atime, &now, inode); EXT4_INODE_SET_XTIME(i_ctime, &now, inode); EXT4_INODE_SET_XTIME(i_mtime, &now, inode); @@ -1040,14 +1057,15 @@ static void init_times(struct ext2_inode_large *inode) increment_version(inode); } -static int update_ctime(ext2_filsys fs, ext2_ino_t ino, - struct ext2_inode_large *pinode) +static int fuse4fs_update_ctime(struct fuse4fs *ff, ext2_ino_t ino, + struct ext2_inode_large *pinode) { - errcode_t err; struct timespec now; struct ext2_inode_large inode; + ext2_filsys fs = ff->fs; + errcode_t err; - get_now(&now); + fuse4fs_get_now(ff, &now); /* If user already has a inode buffer, just update that */ if (pinode) { @@ -1071,12 +1089,13 @@ static int update_ctime(ext2_filsys fs, ext2_ino_t ino, return 0; } -static int update_atime(ext2_filsys fs, ext2_ino_t ino) +static int fuse4fs_update_atime(struct fuse4fs *ff, ext2_ino_t ino) { - errcode_t err; struct ext2_inode_large inode, *pinode; struct timespec atime, mtime, now; + ext2_filsys fs = ff->fs; double datime, dmtime, dnow; + errcode_t err; err = fuse4fs_read_inode(fs, ino, &inode); if (err) @@ -1085,7 +1104,7 @@ static int update_atime(ext2_filsys fs, ext2_ino_t ino) pinode = &inode; EXT4_INODE_GET_XTIME(i_atime, &atime, pinode); EXT4_INODE_GET_XTIME(i_mtime, &mtime, pinode); - get_now(&now); + fuse4fs_get_now(ff, &now); datime = atime.tv_sec + ((double)atime.tv_nsec / NSEC_PER_SEC); dmtime = mtime.tv_sec + ((double)mtime.tv_nsec / NSEC_PER_SEC); @@ -1107,15 +1126,16 @@ static int update_atime(ext2_filsys fs, ext2_ino_t ino) return 0; } -static int update_mtime(ext2_filsys fs, ext2_ino_t ino, - struct ext2_inode_large *pinode) +static int fuse4fs_update_mtime(struct fuse4fs *ff, ext2_ino_t ino, + struct ext2_inode_large *pinode) { - errcode_t err; struct ext2_inode_large inode; struct timespec now; + ext2_filsys fs = ff->fs; + errcode_t err; if (pinode) { - get_now(&now); + fuse4fs_get_now(ff, &now); EXT4_INODE_SET_XTIME(i_mtime, &now, pinode); EXT4_INODE_SET_XTIME(i_ctime, &now, pinode); increment_version(pinode); @@ -1126,7 +1146,7 @@ static int update_mtime(ext2_filsys fs, ext2_ino_t ino, if (err) return translate_error(fs, ino, err); - get_now(&now); + fuse4fs_get_now(ff, &now); EXT4_INODE_SET_XTIME(i_mtime, &now, &inode); EXT4_INODE_SET_XTIME(i_ctime, &now, &inode); increment_version(&inode); @@ -2416,7 +2436,7 @@ static void op_readlink(fuse_req_t req, fuse_ino_t fino) buf[len] = 0; if (fuse4fs_is_writeable(ff)) { - ret = update_atime(fs, ino); + ret = fuse4fs_update_atime(ff, ino); if (ret) goto out; } @@ -2685,7 +2705,7 @@ static void op_mknod(fuse_req_t req, fuse_ino_t fino, const char *name, goto out2; } - ret = update_mtime(fs, parent, NULL); + ret = fuse4fs_update_mtime(ff, parent, NULL); if (ret) goto out2; @@ -2708,7 +2728,7 @@ static void op_mknod(fuse_req_t req, fuse_ino_t fino, const char *name, } inode.i_generation = ff->next_generation++; - init_times(&inode); + fuse4fs_init_timestamps(ff, &inode); err = fuse4fs_write_inode(fs, child, &inode); if (err) { ret = translate_error(fs, child, err); @@ -2770,7 +2790,7 @@ static void op_mkdir(fuse_req_t req, fuse_ino_t fino, const char *name, goto out2; } - ret = update_mtime(fs, parent, NULL); + ret = fuse4fs_update_mtime(ff, parent, NULL); if (ret) goto out2; @@ -2796,7 +2816,7 @@ static void op_mkdir(fuse_req_t req, fuse_ino_t fino, const char *name, if (parent_sgid) inode.i_mode |= S_ISGID; inode.i_generation = ff->next_generation++; - init_times(&inode); + fuse4fs_init_timestamps(ff, &inode); err = fuse4fs_write_inode(fs, child, &inode); if (err) { @@ -3147,7 +3167,7 @@ static int fuse4fs_remove_inode(struct fuse4fs *ff, ext2_ino_t ino) inode.i_links_count--; } - ret = update_ctime(fs, ino, &inode); + ret = fuse4fs_update_ctime(ff, ino, &inode); if (ret) return ret; @@ -3219,7 +3239,7 @@ static int fuse4fs_unlink(struct fuse4fs *ff, ext2_ino_t parent, goto out; } - ret = update_mtime(fs, parent, NULL); + ret = fuse4fs_update_mtime(ff, parent, NULL); if (ret) goto out; out: @@ -3353,7 +3373,7 @@ static int fuse4fs_rmdir(struct fuse4fs *ff, ext2_ino_t parent, goto out; } ext2fs_dec_nlink(EXT2_INODE(&inode)); - ret = update_mtime(fs, rds.parent, &inode); + ret = fuse4fs_update_mtime(ff, rds.parent, &inode); if (ret) goto out; err = fuse4fs_write_inode(fs, rds.parent, &inode); @@ -3457,7 +3477,7 @@ static void op_symlink(fuse_req_t req, const char *target, fuse_ino_t fino, } /* Update parent dir's mtime */ - ret = update_mtime(fs, parent, NULL); + ret = fuse4fs_update_mtime(ff, parent, NULL); if (ret) goto out2; @@ -3480,7 +3500,7 @@ static void op_symlink(fuse_req_t req, const char *target, fuse_ino_t fino, fuse4fs_set_uid(&inode, ctxt->uid); fuse4fs_set_gid(&inode, gid); inode.i_generation = ff->next_generation++; - init_times(&inode); + fuse4fs_init_timestamps(ff, &inode); err = fuse4fs_write_inode(fs, child, &inode); if (err) { @@ -3711,11 +3731,11 @@ static void op_rename(fuse_req_t req, fuse_ino_t from_parent, const char *from, } /* Update timestamps */ - ret = update_ctime(fs, from_ino, NULL); + ret = fuse4fs_update_ctime(ff, from_ino, NULL); if (ret) goto out; - ret = update_mtime(fs, to_dir_ino, NULL); + ret = fuse4fs_update_mtime(ff, to_dir_ino, NULL); if (ret) goto out; @@ -3794,7 +3814,7 @@ static void op_link(fuse_req_t req, fuse_ino_t child_fino, } ext2fs_inc_nlink(fs, EXT2_INODE(&inode)); - ret = update_ctime(fs, child, &inode); + ret = fuse4fs_update_ctime(ff, child, &inode); if (ret) goto out2; @@ -3811,7 +3831,7 @@ static void op_link(fuse_req_t req, fuse_ino_t child_fino, goto out2; } - ret = update_mtime(fs, parent, NULL); + ret = fuse4fs_update_mtime(ff, parent, NULL); if (ret) goto out2; @@ -4047,7 +4067,7 @@ static int fuse4fs_truncate(struct fuse4fs *ff, ext2_ino_t ino, off_t new_size) if (err) return translate_error(fs, ino, err); - ret = update_mtime(fs, ino, NULL); + ret = fuse4fs_update_mtime(ff, ino, NULL); if (ret) return ret; @@ -4249,7 +4269,7 @@ static void op_read(fuse_req_t req, fuse_ino_t fino EXT2FS_ATTR((unused)), } if (fh->check_flags != X_OK && fuse4fs_is_writeable(ff)) { - ret = update_atime(fs, fh->ino); + ret = fuse4fs_update_atime(ff, fh->ino); if (ret) goto out; } @@ -4323,7 +4343,7 @@ static void op_write(fuse_req_t req, fuse_ino_t fino EXT2FS_ATTR((unused)), goto out; } - ret = update_mtime(fs, fh->ino, NULL); + ret = fuse4fs_update_mtime(ff, fh->ino, NULL); if (ret) goto out; @@ -4770,7 +4790,7 @@ static void op_setxattr(fuse_req_t req, fuse_ino_t fino, const char *key, goto out2; } - ret = update_ctime(fs, ino, NULL); + ret = fuse4fs_update_ctime(ff, ino, NULL); out2: err = ext2fs_xattrs_close(&h); if (!ret && err) @@ -4864,7 +4884,7 @@ static void op_removexattr(fuse_req_t req, fuse_ino_t fino, const char *key) goto out2; } - ret = update_ctime(fs, ino, NULL); + ret = fuse4fs_update_ctime(ff, ino, NULL); out2: err = ext2fs_xattrs_close(&h); if (err && !ret) @@ -5011,7 +5031,7 @@ static void __op_readdir(fuse_req_t req, fuse_ino_t fino, size_t size, } if (fuse4fs_is_writeable(ff)) { - ret = update_atime(i.fs, fh->ino); + ret = fuse4fs_update_atime(i.ff, fh->ino); if (ret) goto out; } @@ -5111,7 +5131,7 @@ static void op_create(fuse_req_t req, fuse_ino_t fino, const char *name, goto out2; } - ret = update_mtime(fs, parent, NULL); + ret = fuse4fs_update_mtime(ff, parent, NULL); if (ret) goto out2; } else { @@ -5152,7 +5172,7 @@ static void op_create(fuse_req_t req, fuse_ino_t fino, const char *name, } inode.i_generation = ff->next_generation++; - init_times(&inode); + fuse4fs_init_timestamps(ff, &inode); err = fuse4fs_write_inode(fs, child, &inode); if (err) { ret = translate_error(fs, child, err); @@ -5231,7 +5251,7 @@ static int fuse4fs_utimens(struct fuse4fs *ff, const struct fuse_ctx *ctxt, int ret = 0; if (to_set & (FUSE_SET_ATTR_ATIME_NOW | FUSE_SET_ATTR_MTIME_NOW)) - get_now(&now); + fuse4fs_get_now(ff, &now); if (to_set & FUSE_SET_ATTR_ATIME_NOW) { atime = now; @@ -5369,7 +5389,7 @@ static void op_setattr(fuse_req_t req, fuse_ino_t fino, struct stat *attr, } /* Update ctime for any attribute change */ - ret = update_ctime(fs, ino, &inode); + ret = fuse4fs_update_ctime(ff, ino, &inode); if (ret) goto out; @@ -5451,7 +5471,7 @@ static int ioctl_setflags(struct fuse4fs *ff, const struct fuse_ctx *ctxt, if (ret) return ret; - ret = update_ctime(fs, fh->ino, &inode); + ret = fuse4fs_update_ctime(ff, fh->ino, &inode); if (ret) return ret; @@ -5504,7 +5524,7 @@ static int ioctl_setversion(struct fuse4fs *ff, const struct fuse_ctx *ctxt, inode.i_generation = *indata; - ret = update_ctime(fs, fh->ino, &inode); + ret = fuse4fs_update_ctime(ff, fh->ino, &inode); if (ret) return ret; @@ -5640,7 +5660,7 @@ static int ioctl_fssetxattr(struct fuse4fs *ff, const struct fuse_ctx *ctxt, if (ext2fs_inode_includes(inode_size, i_projid)) inode.i_projid = fsx->fsx_projid; - ret = update_ctime(fs, fh->ino, &inode); + ret = fuse4fs_update_ctime(ff, fh->ino, &inode); if (ret) return ret; @@ -5936,7 +5956,7 @@ static int fuse4fs_allocate_range(struct fuse4fs *ff, } } - err = update_mtime(fs, fh->ino, &inode); + err = fuse4fs_update_mtime(ff, fh->ino, &inode); if (err) return err; @@ -6109,7 +6129,7 @@ static int fuse4fs_punch_range(struct fuse4fs *ff, return translate_error(fs, fh->ino, err); } - err = update_mtime(fs, fh->ino, &inode); + err = fuse4fs_update_mtime(ff, fh->ino, &inode); if (err) return err; @@ -8271,7 +8291,7 @@ static int __translate_error(ext2_filsys fs, ext2_ino_t ino, errcode_t err, error_message(err), func, line); /* Make a note in the error log */ - get_now(&now); + fuse4fs_get_now(ff, &now); ext2fs_set_tstamp(fs->super, s_last_error_time, now.tv_sec); fs->super->s_last_error_ino = ino; fs->super->s_last_error_line = line; diff --git a/misc/fuse2fs.c b/misc/fuse2fs.c index f77d778aec24ec..de712461492e05 100644 --- a/misc/fuse2fs.c +++ b/misc/fuse2fs.c @@ -840,8 +840,24 @@ static inline void fuse2fs_dump_extents(struct fuse2fs *ff, ext2_ino_t ino, ext2fs_extent_free(extents); } -static void get_now(struct timespec *now) +static void fuse2fs_get_now(struct fuse2fs *ff, struct timespec *now) { +#ifdef CLOCK_REALTIME_COARSE + /* + * In iomap mode, the kernel is responsible for maintaining timestamps + * because file writes don't upcall to fuse2fs. The kernel's predicate + * for deciding if [cm]time should be updated bases its decisions off + * [cm]time being an exact match for the coarse clock (instead of + * checking that [cm]time < coarse_clock) which means that fuse2fs + * setting a fine-grained timestamp that is slightly ahead of the + * coarse clock can result in timestamps appearing to go backwards. + * generic/423 doesn't like seeing btime > ctime from statx, so we'll + * use the coarse clock in iomap mode. + */ + if (fuse2fs_iomap_enabled(ff) && + !clock_gettime(CLOCK_REALTIME_COARSE, now)) + return; +#endif #ifdef CLOCK_REALTIME if (!clock_gettime(CLOCK_REALTIME, now)) return; @@ -869,7 +885,7 @@ static void fuse2fs_init_timestamps(struct fuse2fs *ff, ext2_ino_t ino, { struct timespec now; - get_now(&now); + fuse2fs_get_now(ff, &now); EXT4_INODE_SET_XTIME(i_atime, &now, inode); EXT4_INODE_SET_XTIME(i_ctime, &now, inode); EXT4_INODE_SET_XTIME(i_mtime, &now, inode); @@ -888,7 +904,7 @@ static int fuse2fs_update_ctime(struct fuse2fs *ff, ext2_ino_t ino, struct timespec now; struct ext2_inode_large inode; - get_now(&now); + fuse2fs_get_now(ff, &now); /* If user already has a inode buffer, just update that */ if (pinode) { @@ -934,7 +950,7 @@ static int fuse2fs_update_atime(struct fuse2fs *ff, ext2_ino_t ino) pinode = &inode; EXT4_INODE_GET_XTIME(i_atime, &atime, pinode); EXT4_INODE_GET_XTIME(i_mtime, &mtime, pinode); - get_now(&now); + fuse2fs_get_now(ff, &now); datime = atime.tv_sec + ((double)atime.tv_nsec / NSEC_PER_SEC); dmtime = mtime.tv_sec + ((double)mtime.tv_nsec / NSEC_PER_SEC); @@ -969,7 +985,7 @@ static int fuse2fs_update_mtime(struct fuse2fs *ff, ext2_ino_t ino, struct timespec now; if (pinode) { - get_now(&now); + fuse2fs_get_now(ff, &now); EXT4_INODE_SET_XTIME(i_mtime, &now, pinode); EXT4_INODE_SET_XTIME(i_ctime, &now, pinode); increment_version(pinode); @@ -984,7 +1000,7 @@ static int fuse2fs_update_mtime(struct fuse2fs *ff, ext2_ino_t ino, if (err) return translate_error(fs, ino, err); - get_now(&now); + fuse2fs_get_now(ff, &now); EXT4_INODE_SET_XTIME(i_mtime, &now, &inode); EXT4_INODE_SET_XTIME(i_ctime, &now, &inode); increment_version(&inode); @@ -4965,9 +4981,9 @@ static int op_utimens(const char *path, const struct timespec ctv[2], tv[1] = ctv[1]; #ifdef UTIME_NOW if (tv[0].tv_nsec == UTIME_NOW) - get_now(tv); + fuse2fs_get_now(ff, tv); if (tv[1].tv_nsec == UTIME_NOW) - get_now(tv + 1); + fuse2fs_get_now(ff, tv + 1); #endif /* UTIME_NOW */ #ifdef UTIME_OMIT if (tv[0].tv_nsec != UTIME_OMIT) @@ -7708,7 +7724,7 @@ static int __translate_error(ext2_filsys fs, ext2_ino_t ino, errcode_t err, error_message(err), func, line); /* Make a note in the error log */ - get_now(&now); + fuse2fs_get_now(ff, &now); ext2fs_set_tstamp(fs->super, s_last_error_time, now.tv_sec); fs->super->s_last_error_ino = ino; fs->super->s_last_error_line = line;