Date: Wed, 3 Apr 2019 02:29:56 +0000 (UTC) From: Alan Somers <asomers@FreeBSD.org> To: src-committers@freebsd.org, svn-src-projects@freebsd.org Subject: svn commit: r345823 - in projects/fuse2: sys/fs/fuse tests/sys/fs/fusefs Message-ID: <201904030229.x332Tusu086697@repo.freebsd.org>
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Author: asomers Date: Wed Apr 3 02:29:56 2019 New Revision: 345823 URL: https://svnweb.freebsd.org/changeset/base/345823 Log: fusefs: during ftruncate, discard cached data past truncation point During truncate, fusefs was discarding entire cached blocks, but it wasn't zeroing out the unused portion of a final partial block. This resulted in reads returning stale data. PR: 233783 Reported by: fsx Sponsored by: The FreeBSD Foundation Modified: projects/fuse2/sys/fs/fuse/fuse_node.c projects/fuse2/tests/sys/fs/fusefs/setattr.cc Modified: projects/fuse2/sys/fs/fuse/fuse_node.c ============================================================================== --- projects/fuse2/sys/fs/fuse/fuse_node.c Wed Apr 3 01:30:59 2019 (r345822) +++ projects/fuse2/sys/fs/fuse/fuse_node.c Wed Apr 3 02:29:56 2019 (r345823) @@ -79,6 +79,7 @@ __FBSDID("$FreeBSD$"); #include <sys/fcntl.h> #include <sys/fnv_hash.h> #include <sys/priv.h> +#include <sys/buf.h> #include <security/mac/mac_framework.h> #include <vm/vm.h> #include <vm/vm_extern.h> @@ -413,17 +414,45 @@ fuse_vnode_setsize(struct vnode *vp, struct ucred *cre { struct fuse_vnode_data *fvdat = VTOFUD(vp); off_t oldsize; + size_t iosize; + struct buf *bp = NULL; int err = 0; ASSERT_VOP_ELOCKED(vp, "fuse_vnode_setsize"); + iosize = fuse_iosize(vp); oldsize = fvdat->filesize; fvdat->filesize = newsize; fvdat->flag |= FN_SIZECHANGE; if (newsize < oldsize) { + daddr_t lbn; + size_t zsize; + err = vtruncbuf(vp, cred, newsize, fuse_iosize(vp)); + if (err) + goto out; + if (newsize % iosize == 0) + goto out; + /* + * Zero the contents of the last partial block. + * Sure seems like vtruncbuf should do this for us. + */ + + lbn = newsize / iosize; + bp = getblk(vp, lbn, iosize, PCATCH, 0, 0); + if (!bp) { + err = EINTR; + goto out; + } + if (!(bp->b_flags & B_CACHE)) + goto out; /* Nothing to do */ + zsize = (lbn + 1) * iosize - newsize; + bzero(bp->b_data + newsize - lbn * iosize, zsize); } +out: + if (bp) + brelse(bp); vnode_pager_setsize(vp, newsize); return err; } Modified: projects/fuse2/tests/sys/fs/fusefs/setattr.cc ============================================================================== --- projects/fuse2/tests/sys/fs/fusefs/setattr.cc Wed Apr 3 01:30:59 2019 (r345822) +++ projects/fuse2/tests/sys/fs/fusefs/setattr.cc Wed Apr 3 02:29:56 2019 (r345823) @@ -366,6 +366,116 @@ TEST_F(Setattr, truncate) { EXPECT_EQ(0, truncate(FULLPATH, newsize)) << strerror(errno); } +/* + * Truncating a file should discard cached data past the truncation point. + * This is a regression test for bug 233783. The bug only applies when + * vfs.fusefs.data_cache_mode=1 or 2, but the test should pass regardless. + */ +TEST_F(Setattr, truncate_discards_cached_data) { + const char FULLPATH[] = "mountpoint/some_file.txt"; + const char RELPATH[] = "some_file.txt"; + void *w0buf, *rbuf, *expected; + off_t w0_offset = 0x1b8df; + size_t w0_size = 0x61e8; + off_t r_offset = 0xe1e6; + off_t r_size = 0xe229; + size_t trunc0_size = 0x10016; + size_t trunc1_size = 131072; + size_t cur_size = 0; + const uint64_t ino = 42; + mode_t mode = S_IFREG | 0644; + int fd; + + w0buf = malloc(w0_size); + ASSERT_NE(NULL, w0buf) << strerror(errno); + memset(w0buf, 'X', w0_size); + + rbuf = malloc(r_size); + ASSERT_NE(NULL, rbuf) << strerror(errno); + + expected = malloc(r_size); + ASSERT_NE(NULL, expected) << strerror(errno); + memset(expected, 0, r_size); + + expect_lookup(RELPATH, ino, mode, 0, 1); + expect_open(ino, O_RDWR, 1); + EXPECT_CALL(*m_mock, process( + ResultOf([=](auto in) { + return (in->header.opcode == FUSE_GETATTR && + in->header.nodeid == ino); + }, Eq(true)), + _) + ).WillRepeatedly(Invoke(ReturnImmediate([&](auto i __unused, auto out) { + SET_OUT_HEADER_LEN(out, attr); + out->body.attr.attr.ino = ino; + out->body.attr.attr.mode = mode; + out->body.attr.attr.size = cur_size; + }))); + /* + * The exact pattern of FUSE_WRITE operations depends on the setting of + * vfs.fusefs.data_cache_mode. But it's not important for this test. + * Just set the mocks to accept anything + */ + EXPECT_CALL(*m_mock, process( + ResultOf([=](auto in) { + return (in->header.opcode == FUSE_WRITE); + }, Eq(true)), + _) + ).WillRepeatedly(Invoke(ReturnImmediate([&](auto in, auto out) { + SET_OUT_HEADER_LEN(out, write); + out->body.attr.attr.ino = ino; + out->body.write.size = in->body.write.size; + cur_size = std::max(cur_size, + in->body.write.size + in->body.write.offset); + }))); + + EXPECT_CALL(*m_mock, process( + ResultOf([=](auto in) { + return (in->header.opcode == FUSE_SETATTR && + in->header.nodeid == ino && + (in->body.setattr.valid & FATTR_SIZE)); + }, Eq(true)), + _) + ).WillRepeatedly(Invoke(ReturnImmediate([&](auto in, auto out) { + auto trunc_size = in->body.setattr.size; + SET_OUT_HEADER_LEN(out, attr); + out->body.attr.attr.ino = ino; + out->body.attr.attr.mode = mode; + out->body.attr.attr.size = trunc_size; + cur_size = trunc_size; + }))); + + /* exact pattern of FUSE_READ depends on vfs.fusefs.data_cache_mode */ + EXPECT_CALL(*m_mock, process( + ResultOf([=](auto in) { + return (in->header.opcode == FUSE_READ); + }, Eq(true)), + _) + ).WillRepeatedly(Invoke(ReturnImmediate([&](auto in, auto out) { + auto osize = std::min(cur_size - in->body.read.offset, + (size_t)in->body.read.size); + out->header.len = sizeof(struct fuse_out_header) + osize; + bzero(out->body.bytes, osize); + }))); + + fd = open(FULLPATH, O_RDWR, 0644); + ASSERT_LE(0, fd) << strerror(errno); + + ASSERT_EQ((ssize_t)w0_size, pwrite(fd, w0buf, w0_size, w0_offset)); + /* 1st truncate should discard cached data */ + EXPECT_EQ(0, ftruncate(fd, trunc0_size)) << strerror(errno); + /* 2nd truncate extends file into previously cached data */ + EXPECT_EQ(0, ftruncate(fd, trunc1_size)) << strerror(errno); + /* Read should return all zeros */ + ASSERT_EQ((ssize_t)r_size, pread(fd, rbuf, r_size, r_offset)); + + ASSERT_EQ(0, memcmp(expected, rbuf, r_size)); + + free(expected); + free(rbuf); + free(w0buf); +} + /* Change a file's timestamps */ TEST_F(Setattr, utimensat) { const char FULLPATH[] = "mountpoint/some_file.txt";
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