/* * CDDL HEADER START * * The contents of this file are subject to the terms of the * Common Development and Distribution License (the "License"). * You may not use this file except in compliance with the License. * * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE * or http://www.opensolaris.org/os/licensing. * See the License for the specific language governing permissions * and limitations under the License. * * When distributing Covered Code, include this CDDL HEADER in each * file and include the License file at usr/src/OPENSOLARIS.LICENSE. * If applicable, add the following below this CDDL HEADER, with the * fields enclosed by brackets "[]" replaced with your own identifying * information: Portions Copyright [yyyy] [name of copyright owner] * * CDDL HEADER END */ /* * Copyright 2006 Sun Microsystems, Inc. All rights reserved. * Use is subject to license terms. */ #pragma ident "%Z%%M% %I% %E% SMI" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "fs/fs_subr.h" #include #include #include /* * Programming rules. * * Each vnode op performs some logical unit of work. To do this, the ZPL must * properly lock its in-core state, create a DMU transaction, do the work, * record this work in the intent log (ZIL), commit the DMU transaction, * and wait the the intent log to commit if it's is a synchronous operation. * Morover, the vnode ops must work in both normal and log replay context. * The ordering of events is important to avoid deadlocks and references * to freed memory. The example below illustrates the following Big Rules: * * (1) A check must be made in each zfs thread for a mounted file system. * This is done avoiding races using ZFS_ENTER(zfsvfs). * A ZFS_EXIT(zfsvfs) is needed before all returns. * * (2) VN_RELE() should always be the last thing except for zil_commit() * (if necessary) and ZFS_EXIT(). This is for 3 reasons: * First, if it's the last reference, the vnode/znode * can be freed, so the zp may point to freed memory. Second, the last * reference will call zfs_zinactive(), which may induce a lot of work -- * pushing cached pages (which acquires range locks) and syncing out * cached atime changes. Third, zfs_zinactive() may require a new tx, * which could deadlock the system if you were already holding one. * * (3) All range locks must be grabbed before calling dmu_tx_assign(), * as they can span dmu_tx_assign() calls. * * (4) Always pass zfsvfs->z_assign as the second argument to dmu_tx_assign(). * In normal operation, this will be TXG_NOWAIT. During ZIL replay, * it will be a specific txg. Either way, dmu_tx_assign() never blocks. * This is critical because we don't want to block while holding locks. * Note, in particular, that if a lock is sometimes acquired before * the tx assigns, and sometimes after (e.g. z_lock), then failing to * use a non-blocking assign can deadlock the system. The scenario: * * Thread A has grabbed a lock before calling dmu_tx_assign(). * Thread B is in an already-assigned tx, and blocks for this lock. * Thread A calls dmu_tx_assign(TXG_WAIT) and blocks in txg_wait_open() * forever, because the previous txg can't quiesce until B's tx commits. * * If dmu_tx_assign() returns ERESTART and zfsvfs->z_assign is TXG_NOWAIT, * then drop all locks, call dmu_tx_wait(), and try again. * * (5) If the operation succeeded, generate the intent log entry for it * before dropping locks. This ensures that the ordering of events * in the intent log matches the order in which they actually occurred. * * (6) At the end of each vnode op, the DMU tx must always commit, * regardless of whether there were any errors. * * (7) After dropping all locks, invoke zil_commit(zilog, seq, foid) * to ensure that synchronous semantics are provided when necessary. * * In general, this is how things should be ordered in each vnode op: * * ZFS_ENTER(zfsvfs); // exit if unmounted * top: * zfs_dirent_lock(&dl, ...) // lock directory entry (may VN_HOLD()) * rw_enter(...); // grab any other locks you need * tx = dmu_tx_create(...); // get DMU tx * dmu_tx_hold_*(); // hold each object you might modify * error = dmu_tx_assign(tx, zfsvfs->z_assign); // try to assign * if (error) { * rw_exit(...); // drop locks * zfs_dirent_unlock(dl); // unlock directory entry * VN_RELE(...); // release held vnodes * if (error == ERESTART && zfsvfs->z_assign == TXG_NOWAIT) { * dmu_tx_wait(tx); * dmu_tx_abort(tx); * goto top; * } * dmu_tx_abort(tx); // abort DMU tx * ZFS_EXIT(zfsvfs); // finished in zfs * return (error); // really out of space * } * error = do_real_work(); // do whatever this VOP does * if (error == 0) * zfs_log_*(...); // on success, make ZIL entry * dmu_tx_commit(tx); // commit DMU tx -- error or not * rw_exit(...); // drop locks * zfs_dirent_unlock(dl); // unlock directory entry * VN_RELE(...); // release held vnodes * zil_commit(zilog, seq, foid); // synchronous when necessary * ZFS_EXIT(zfsvfs); // finished in zfs * return (error); // done, report error */ /* ARGSUSED */ static int zfs_open(vnode_t **vpp, int flag, cred_t *cr) { znode_t *zp = VTOZ(*vpp); /* Keep a count of the synchronous opens in the znode */ if (flag & (FSYNC | FDSYNC)) atomic_inc_32(&zp->z_sync_cnt); return (0); } /* ARGSUSED */ static int zfs_close(vnode_t *vp, int flag, int count, offset_t offset, cred_t *cr) { znode_t *zp = VTOZ(vp); /* Decrement the synchronous opens in the znode */ if (flag & (FSYNC | FDSYNC)) atomic_dec_32(&zp->z_sync_cnt); /* * Clean up any locks held by this process on the vp. */ cleanlocks(vp, ddi_get_pid(), 0); cleanshares(vp, ddi_get_pid()); return (0); } /* * Lseek support for finding holes (cmd == _FIO_SEEK_HOLE) and * data (cmd == _FIO_SEEK_DATA). "off" is an in/out parameter. */ static int zfs_holey(vnode_t *vp, int cmd, offset_t *off) { znode_t *zp = VTOZ(vp); uint64_t noff = (uint64_t)*off; /* new offset */ uint64_t file_sz; int error; boolean_t hole; file_sz = zp->z_phys->zp_size; if (noff >= file_sz) { return (ENXIO); } if (cmd == _FIO_SEEK_HOLE) hole = B_TRUE; else hole = B_FALSE; error = dmu_offset_next(zp->z_zfsvfs->z_os, zp->z_id, hole, &noff); /* end of file? */ if ((error == ESRCH) || (noff > file_sz)) { /* * Handle the virtual hole at the end of file. */ if (hole) { *off = file_sz; return (0); } return (ENXIO); } if (noff < *off) return (error); *off = noff; return (error); } /* ARGSUSED */ static int zfs_ioctl(vnode_t *vp, int com, intptr_t data, int flag, cred_t *cred, int *rvalp) { offset_t off; int error; zfsvfs_t *zfsvfs; switch (com) { case _FIOFFS: return (zfs_sync(vp->v_vfsp, 0, cred)); /* * The following two ioctls are used by bfu. Faking out, * necessary to avoid bfu errors. */ case _FIOGDIO: case _FIOSDIO: return (0); case _FIO_SEEK_DATA: case _FIO_SEEK_HOLE: if (ddi_copyin((void *)data, &off, sizeof (off), flag)) return (EFAULT); zfsvfs = VTOZ(vp)->z_zfsvfs; ZFS_ENTER(zfsvfs); /* offset parameter is in/out */ error = zfs_holey(vp, com, &off); ZFS_EXIT(zfsvfs); if (error) return (error); if (ddi_copyout(&off, (void *)data, sizeof (off), flag)) return (EFAULT); return (0); } return (ENOTTY); } /* * When a file is memory mapped, we must keep the IO data synchronized * between the DMU cache and the memory mapped pages. What this means: * * On Write: If we find a memory mapped page, we write to *both* * the page and the dmu buffer. * * NOTE: We will always "break up" the IO into PAGESIZE uiomoves when * the file is memory mapped. */ static int mappedwrite(vnode_t *vp, uint64_t woff, int nbytes, uio_t *uio, dmu_tx_t *tx) { znode_t *zp = VTOZ(vp); zfsvfs_t *zfsvfs = zp->z_zfsvfs; int64_t start, off; int len = nbytes; int error = 0; start = uio->uio_loffset; off = start & PAGEOFFSET; for (start &= PAGEMASK; len > 0; start += PAGESIZE) { page_t *pp; uint64_t bytes = MIN(PAGESIZE - off, len); /* * We don't want a new page to "appear" in the middle of * the file update (because it may not get the write * update data), so we grab a lock to block * zfs_getpage(). */ rw_enter(&zp->z_map_lock, RW_WRITER); if (pp = page_lookup(vp, start, SE_SHARED)) { caddr_t va; rw_exit(&zp->z_map_lock); va = ppmapin(pp, PROT_READ | PROT_WRITE, (caddr_t)-1L); error = uiomove(va+off, bytes, UIO_WRITE, uio); if (error == 0) { dmu_write(zfsvfs->z_os, zp->z_id, woff, bytes, va+off, tx); } ppmapout(va); page_unlock(pp); } else { error = dmu_write_uio(zfsvfs->z_os, zp->z_id, woff, bytes, uio, tx); rw_exit(&zp->z_map_lock); } len -= bytes; woff += bytes; off = 0; if (error) break; } return (error); } /* * When a file is memory mapped, we must keep the IO data synchronized * between the DMU cache and the memory mapped pages. What this means: * * On Read: We "read" preferentially from memory mapped pages, * else we default from the dmu buffer. * * NOTE: We will always "break up" the IO into PAGESIZE uiomoves when * the file is memory mapped. */ static int mappedread(vnode_t *vp, char *addr, int nbytes, uio_t *uio) { int64_t start, off, bytes; int len = nbytes; int error = 0; start = uio->uio_loffset; off = start & PAGEOFFSET; for (start &= PAGEMASK; len > 0; start += PAGESIZE) { page_t *pp; bytes = MIN(PAGESIZE - off, len); if (pp = page_lookup(vp, start, SE_SHARED)) { caddr_t va; va = ppmapin(pp, PROT_READ, (caddr_t)-1L); error = uiomove(va + off, bytes, UIO_READ, uio); ppmapout(va); page_unlock(pp); } else { /* XXX use dmu_read here? */ error = uiomove(addr, bytes, UIO_READ, uio); } len -= bytes; addr += bytes; off = 0; if (error) break; } return (error); } uint_t zfs_read_chunk_size = 1024 * 1024; /* Tunable */ /* * Read bytes from specified file into supplied buffer. * * IN: vp - vnode of file to be read from. * uio - structure supplying read location, range info, * and return buffer. * ioflag - SYNC flags; used to provide FRSYNC semantics. * cr - credentials of caller. * * OUT: uio - updated offset and range, buffer filled. * * RETURN: 0 if success * error code if failure * * Side Effects: * vp - atime updated if byte count > 0 */ /* ARGSUSED */ static int zfs_read(vnode_t *vp, uio_t *uio, int ioflag, cred_t *cr, caller_context_t *ct) { znode_t *zp = VTOZ(vp); zfsvfs_t *zfsvfs = zp->z_zfsvfs; uint64_t delta; ssize_t n, size, cnt, ndone; int error, i, numbufs; dmu_buf_t *dbp, **dbpp; rl_t *rl; ZFS_ENTER(zfsvfs); /* * Validate file offset */ if (uio->uio_loffset < (offset_t)0) { ZFS_EXIT(zfsvfs); return (EINVAL); } /* * Fasttrack empty reads */ if (uio->uio_resid == 0) { ZFS_EXIT(zfsvfs); return (0); } /* * Check for mandatory locks */ if (MANDMODE((mode_t)zp->z_phys->zp_mode)) { if (error = chklock(vp, FREAD, uio->uio_loffset, uio->uio_resid, uio->uio_fmode, ct)) { ZFS_EXIT(zfsvfs); return (error); } } /* * If we're in FRSYNC mode, sync out this znode before reading it. */ if (ioflag & FRSYNC) zil_commit(zfsvfs->z_log, zp->z_last_itx, zp->z_id); /* * Lock the range against changes. */ rl = zfs_range_lock(zp, uio->uio_loffset, uio->uio_resid, RL_READER); /* * If we are reading past end-of-file we can skip * to the end; but we might still need to set atime. */ if (uio->uio_loffset >= zp->z_phys->zp_size) { cnt = 0; error = 0; goto out; } cnt = MIN(uio->uio_resid, zp->z_phys->zp_size - uio->uio_loffset); for (ndone = 0; ndone < cnt; ndone += zfs_read_chunk_size) { ASSERT(uio->uio_loffset < zp->z_phys->zp_size); n = MIN(zfs_read_chunk_size, zp->z_phys->zp_size - uio->uio_loffset); n = MIN(n, cnt); error = dmu_buf_hold_array_by_bonus(zp->z_dbuf, uio->uio_loffset, n, TRUE, FTAG, &numbufs, &dbpp); if (error) goto out; /* * Compute the adjustment to align the dmu buffers * with the uio buffer. */ delta = uio->uio_loffset - dbpp[0]->db_offset; for (i = 0; i < numbufs; i++) { if (n < 0) break; dbp = dbpp[i]; size = dbp->db_size - delta; /* * XXX -- this is correct, but may be suboptimal. * If the pages are all clean, we don't need to * go through mappedread(). Maybe the VMODSORT * stuff can help us here. */ if (vn_has_cached_data(vp)) { error = mappedread(vp, (caddr_t)dbp->db_data + delta, (n < size ? n : size), uio); } else { error = uiomove((caddr_t)dbp->db_data + delta, (n < size ? n : size), UIO_READ, uio); } if (error) { dmu_buf_rele_array(dbpp, numbufs, FTAG); goto out; } n -= dbp->db_size; if (delta) { n += delta; delta = 0; } } dmu_buf_rele_array(dbpp, numbufs, FTAG); } out: zfs_range_unlock(rl); ZFS_ACCESSTIME_STAMP(zfsvfs, zp); ZFS_EXIT(zfsvfs); return (error); } /* * Fault in the pages of the first n bytes specified by the uio structure. * 1 byte in each page is touched and the uio struct is unmodified. * Any error will exit this routine as this is only a best * attempt to get the pages resident. This is a copy of ufs_trans_touch(). */ static void zfs_prefault_write(ssize_t n, struct uio *uio) { struct iovec *iov; ulong_t cnt, incr; caddr_t p; uint8_t tmp; iov = uio->uio_iov; while (n) { cnt = MIN(iov->iov_len, n); if (cnt == 0) { /* empty iov entry */ iov++; continue; } n -= cnt; /* * touch each page in this segment. */ p = iov->iov_base; while (cnt) { switch (uio->uio_segflg) { case UIO_USERSPACE: case UIO_USERISPACE: if (fuword8(p, &tmp)) return; break; case UIO_SYSSPACE: if (kcopy(p, &tmp, 1)) return; break; } incr = MIN(cnt, PAGESIZE); p += incr; cnt -= incr; } /* * touch the last byte in case it straddles a page. */ p--; switch (uio->uio_segflg) { case UIO_USERSPACE: case UIO_USERISPACE: if (fuword8(p, &tmp)) return; break; case UIO_SYSSPACE: if (kcopy(p, &tmp, 1)) return; break; } iov++; } } /* * Write the bytes to a file. * * IN: vp - vnode of file to be written to. * uio - structure supplying write location, range info, * and data buffer. * ioflag - FAPPEND flag set if in append mode. * cr - credentials of caller. * * OUT: uio - updated offset and range. * * RETURN: 0 if success * error code if failure * * Timestamps: * vp - ctime|mtime updated if byte count > 0 */ /* ARGSUSED */ static int zfs_write(vnode_t *vp, uio_t *uio, int ioflag, cred_t *cr, caller_context_t *ct) { znode_t *zp = VTOZ(vp); rlim64_t limit = uio->uio_llimit; ssize_t start_resid = uio->uio_resid; ssize_t tx_bytes; uint64_t end_size; dmu_tx_t *tx; zfsvfs_t *zfsvfs = zp->z_zfsvfs; zilog_t *zilog = zfsvfs->z_log; offset_t woff; ssize_t n, nbytes; rl_t *rl; int max_blksz = zfsvfs->z_max_blksz; int error; /* * Fasttrack empty write */ n = start_resid; if (n == 0) return (0); if (limit == RLIM64_INFINITY || limit > MAXOFFSET_T) limit = MAXOFFSET_T; ZFS_ENTER(zfsvfs); /* * Pre-fault the pages to ensure slow (eg NFS) pages * don't hold up txg. */ zfs_prefault_write(n, uio); /* * If in append mode, set the io offset pointer to eof. */ if (ioflag & FAPPEND) { /* * Range lock for a file append: * The value for the start of range will be determined by * zfs_range_lock() (to guarantee append semantics). * If this write will cause the block size to increase, * zfs_range_lock() will lock the entire file, so we must * later reduce the range after we grow the block size. */ rl = zfs_range_lock(zp, 0, n, RL_APPEND); if (rl->r_len == UINT64_MAX) { /* overlocked, zp_size can't change */ woff = uio->uio_loffset = zp->z_phys->zp_size; } else { woff = uio->uio_loffset = rl->r_off; } } else { woff = uio->uio_loffset; /* * Validate file offset */ if (woff < 0) { ZFS_EXIT(zfsvfs); return (EINVAL); } /* * If we need to grow the block size then zfs_range_lock() * will lock a wider range than we request here. * Later after growing the block size we reduce the range. */ rl = zfs_range_lock(zp, woff, n, RL_WRITER); } if (woff >= limit) { error = EFBIG; goto no_tx_done; } if ((woff + n) > limit || woff > (limit - n)) n = limit - woff; /* * Check for mandatory locks */ if (MANDMODE((mode_t)zp->z_phys->zp_mode) && (error = chklock(vp, FWRITE, woff, n, uio->uio_fmode, ct)) != 0) goto no_tx_done; end_size = MAX(zp->z_phys->zp_size, woff + n); top: tx = dmu_tx_create(zfsvfs->z_os); dmu_tx_hold_bonus(tx, zp->z_id); dmu_tx_hold_write(tx, zp->z_id, woff, MIN(n, max_blksz)); error = dmu_tx_assign(tx, zfsvfs->z_assign); if (error) { if (error == ERESTART && zfsvfs->z_assign == TXG_NOWAIT) { dmu_tx_wait(tx); dmu_tx_abort(tx); goto top; } dmu_tx_abort(tx); goto no_tx_done; } /* * If zfs_range_lock() over-locked we grow the blocksize * and then reduce the lock range. */ if (rl->r_len == UINT64_MAX) { uint64_t new_blksz; if (zp->z_blksz > max_blksz) { ASSERT(!ISP2(zp->z_blksz)); new_blksz = MIN(end_size, SPA_MAXBLOCKSIZE); } else { new_blksz = MIN(end_size, max_blksz); } zfs_grow_blocksize(zp, new_blksz, tx); zfs_range_reduce(rl, woff, n); } /* * The file data does not fit in the znode "cache", so we * will be writing to the file block data buffers. * Each buffer will be written in a separate transaction; * this keeps the intent log records small and allows us * to do more fine-grained space accounting. */ while (n > 0) { /* * XXX - should we really limit each write to z_max_blksz? * Perhaps we should use SPA_MAXBLOCKSIZE chunks? */ nbytes = MIN(n, max_blksz - P2PHASE(woff, max_blksz)); rw_enter(&zp->z_map_lock, RW_READER); tx_bytes = uio->uio_resid; if (vn_has_cached_data(vp)) { rw_exit(&zp->z_map_lock); error = mappedwrite(vp, woff, nbytes, uio, tx); } else { error = dmu_write_uio(zfsvfs->z_os, zp->z_id, woff, nbytes, uio, tx); rw_exit(&zp->z_map_lock); } tx_bytes -= uio->uio_resid; if (error) { /* XXX - do we need to "clean up" the dmu buffer? */ break; } ASSERT(tx_bytes == nbytes); /* * Clear Set-UID/Set-GID bits on successful write if not * privileged and at least one of the excute bits is set. * * It would be nice to to this after all writes have * been done, but that would still expose the ISUID/ISGID * to another app after the partial write is committed. */ mutex_enter(&zp->z_acl_lock); if ((zp->z_phys->zp_mode & (S_IXUSR | (S_IXUSR >> 3) | (S_IXUSR >> 6))) != 0 && (zp->z_phys->zp_mode & (S_ISUID | S_ISGID)) != 0 && secpolicy_vnode_setid_retain(cr, (zp->z_phys->zp_mode & S_ISUID) != 0 && zp->z_phys->zp_uid == 0) != 0) { zp->z_phys->zp_mode &= ~(S_ISUID | S_ISGID); } mutex_exit(&zp->z_acl_lock); n -= nbytes; if (n <= 0) break; /* * We have more work ahead of us, so wrap up this transaction * and start another. Exact same logic as tx_done below. */ while ((end_size = zp->z_phys->zp_size) < uio->uio_loffset) { dmu_buf_will_dirty(zp->z_dbuf, tx); (void) atomic_cas_64(&zp->z_phys->zp_size, end_size, uio->uio_loffset); } zfs_time_stamper(zp, CONTENT_MODIFIED, tx); zfs_log_write(zilog, tx, TX_WRITE, zp, woff, tx_bytes, ioflag, uio); dmu_tx_commit(tx); /* * Start another transaction. */ woff = uio->uio_loffset; tx = dmu_tx_create(zfsvfs->z_os); dmu_tx_hold_bonus(tx, zp->z_id); dmu_tx_hold_write(tx, zp->z_id, woff, MIN(n, max_blksz)); error = dmu_tx_assign(tx, zfsvfs->z_assign); if (error) { if (error == ERESTART && zfsvfs->z_assign == TXG_NOWAIT) { dmu_tx_wait(tx); dmu_tx_abort(tx); goto top; } dmu_tx_abort(tx); goto no_tx_done; } } tx_done: if (tx_bytes != 0) { /* * Update the file size if it has changed; account * for possible concurrent updates. */ while ((end_size = zp->z_phys->zp_size) < uio->uio_loffset) { dmu_buf_will_dirty(zp->z_dbuf, tx); (void) atomic_cas_64(&zp->z_phys->zp_size, end_size, uio->uio_loffset); } zfs_time_stamper(zp, CONTENT_MODIFIED, tx); zfs_log_write(zilog, tx, TX_WRITE, zp, woff, tx_bytes, ioflag, uio); } dmu_tx_commit(tx); no_tx_done: zfs_range_unlock(rl); /* * If we're in replay mode, or we made no progress, return error. * Otherwise, it's at least a partial write, so it's successful. */ if (zfsvfs->z_assign >= TXG_INITIAL || uio->uio_resid == start_resid) { ZFS_EXIT(zfsvfs); return (error); } if (ioflag & (FSYNC | FDSYNC)) zil_commit(zilog, zp->z_last_itx, zp->z_id); ZFS_EXIT(zfsvfs); return (0); } void zfs_get_done(dmu_buf_t *db, void *vzgd) { zgd_t *zgd = (zgd_t *)vzgd; rl_t *rl = zgd->zgd_rl; vnode_t *vp = ZTOV(rl->r_zp); dmu_buf_rele(db, vzgd); zfs_range_unlock(rl); VN_RELE(vp); zil_add_vdev(zgd->zgd_zilog, DVA_GET_VDEV(BP_IDENTITY(zgd->zgd_bp))); kmem_free(zgd, sizeof (zgd_t)); } /* * Get data to generate a TX_WRITE intent log record. */ int zfs_get_data(void *arg, lr_write_t *lr, char *buf, zio_t *zio) { zfsvfs_t *zfsvfs = arg; objset_t *os = zfsvfs->z_os; znode_t *zp; uint64_t off = lr->lr_offset; dmu_buf_t *db; rl_t *rl; zgd_t *zgd; int dlen = lr->lr_length; /* length of user data */ int error = 0; ASSERT(zio); ASSERT(dlen != 0); /* * Nothing to do if the file has been removed */ if (zfs_zget(zfsvfs, lr->lr_foid, &zp) != 0) return (ENOENT); if (zp->z_reap) { VN_RELE(ZTOV(zp)); return (ENOENT); } /* * Write records come in two flavors: immediate and indirect. * For small writes it's cheaper to store the data with the * log record (immediate); for large writes it's cheaper to * sync the data and get a pointer to it (indirect) so that * we don't have to write the data twice. */ if (buf != NULL) { /* immediate write */ rl = zfs_range_lock(zp, off, dlen, RL_READER); /* test for truncation needs to be done while range locked */ if (off >= zp->z_phys->zp_size) { error = ENOENT; goto out; } VERIFY(0 == dmu_read(os, lr->lr_foid, off, dlen, buf)); } else { /* indirect write */ uint64_t boff; /* block starting offset */ ASSERT3U(dlen, <=, zp->z_blksz); /* * Have to lock the whole block to ensure when it's * written out and it's checksum is being calculated * that no one can change the data. We need to re-check * blocksize after we get the lock in case it's changed! */ for (;;) { if (ISP2(zp->z_blksz)) { boff = P2ALIGN_TYPED(off, zp->z_blksz, uint64_t); } else { boff = 0; } dlen = zp->z_blksz; rl = zfs_range_lock(zp, boff, dlen, RL_READER); if (zp->z_blksz == dlen) break; zfs_range_unlock(rl); } /* test for truncation needs to be done while range locked */ if (off >= zp->z_phys->zp_size) { error = ENOENT; goto out; } zgd = (zgd_t *)kmem_alloc(sizeof (zgd_t), KM_SLEEP); zgd->zgd_rl = rl; zgd->zgd_zilog = zfsvfs->z_log; zgd->zgd_bp = &lr->lr_blkptr; VERIFY(0 == dmu_buf_hold(os, lr->lr_foid, boff, zgd, &db)); ASSERT(boff == db->db_offset); lr->lr_blkoff = off - boff; error = dmu_sync(zio, db, &lr->lr_blkptr, lr->lr_common.lrc_txg, zfs_get_done, zgd); if (error == 0) { zil_add_vdev(zfsvfs->z_log, DVA_GET_VDEV(BP_IDENTITY(&lr->lr_blkptr))); } /* * If we get EINPROGRESS, then we need to wait for a * write IO initiated by dmu_sync() to complete before * we can release this dbuf. We will finish everything * up in the zfs_get_done() callback. */ if (error == EINPROGRESS) return (0); dmu_buf_rele(db, zgd); kmem_free(zgd, sizeof (zgd_t)); } out: zfs_range_unlock(rl); VN_RELE(ZTOV(zp)); return (error); } /*ARGSUSED*/ static int zfs_access(vnode_t *vp, int mode, int flags, cred_t *cr) { znode_t *zp = VTOZ(vp); zfsvfs_t *zfsvfs = zp->z_zfsvfs; int error; ZFS_ENTER(zfsvfs); error = zfs_zaccess_rwx(zp, mode, cr); ZFS_EXIT(zfsvfs); return (error); } /* * Lookup an entry in a directory, or an extended attribute directory. * If it exists, return a held vnode reference for it. * * IN: dvp - vnode of directory to search. * nm - name of entry to lookup. * pnp - full pathname to lookup [UNUSED]. * flags - LOOKUP_XATTR set if looking for an attribute. * rdir - root directory vnode [UNUSED]. * cr - credentials of caller. * * OUT: vpp - vnode of located entry, NULL if not found. * * RETURN: 0 if success * error code if failure * * Timestamps: * NA */ /* ARGSUSED */ static int zfs_lookup(vnode_t *dvp, char *nm, vnode_t **vpp, struct pathname *pnp, int flags, vnode_t *rdir, cred_t *cr) { znode_t *zdp = VTOZ(dvp); zfsvfs_t *zfsvfs = zdp->z_zfsvfs; int error; ZFS_ENTER(zfsvfs); *vpp = NULL; if (flags & LOOKUP_XATTR) { /* * We don't allow recursive attributes.. * Maybe someday we will. */ if (zdp->z_phys->zp_flags & ZFS_XATTR) { ZFS_EXIT(zfsvfs); return (EINVAL); } if (error = zfs_get_xattrdir(VTOZ(dvp), vpp, cr)) { ZFS_EXIT(zfsvfs); return (error); } /* * Do we have permission to get into attribute directory? */ if (error = zfs_zaccess(VTOZ(*vpp), ACE_EXECUTE, cr)) { VN_RELE(*vpp); } ZFS_EXIT(zfsvfs); return (error); } if (dvp->v_type != VDIR) { ZFS_EXIT(zfsvfs); return (ENOTDIR); } /* * Check accessibility of directory. */ if (error = zfs_zaccess(zdp, ACE_EXECUTE, cr)) { ZFS_EXIT(zfsvfs); return (error); } if ((error = zfs_dirlook(zdp, nm, vpp)) == 0) { /* * Convert device special files */ if (IS_DEVVP(*vpp)) { vnode_t *svp; svp = specvp(*vpp, (*vpp)->v_rdev, (*vpp)->v_type, cr); VN_RELE(*vpp); if (svp == NULL) error = ENOSYS; else *vpp = svp; } } ZFS_EXIT(zfsvfs); return (error); } /* * Attempt to create a new entry in a directory. If the entry * already exists, truncate the file if permissible, else return * an error. Return the vp of the created or trunc'd file. * * IN: dvp - vnode of directory to put new file entry in. * name - name of new file entry. * vap - attributes of new file. * excl - flag indicating exclusive or non-exclusive mode. * mode - mode to open file with. * cr - credentials of caller. * flag - large file flag [UNUSED]. * * OUT: vpp - vnode of created or trunc'd entry. * * RETURN: 0 if success * error code if failure * * Timestamps: * dvp - ctime|mtime updated if new entry created * vp - ctime|mtime always, atime if new */ /* ARGSUSED */ static int zfs_create(vnode_t *dvp, char *name, vattr_t *vap, vcexcl_t excl, int mode, vnode_t **vpp, cred_t *cr, int flag) { znode_t *zp, *dzp = VTOZ(dvp); zfsvfs_t *zfsvfs = dzp->z_zfsvfs; zilog_t *zilog = zfsvfs->z_log; objset_t *os = zfsvfs->z_os; zfs_dirlock_t *dl; dmu_tx_t *tx; int error; uint64_t zoid; ZFS_ENTER(zfsvfs); top: *vpp = NULL; if ((vap->va_mode & VSVTX) && secpolicy_vnode_stky_modify(cr)) vap->va_mode &= ~VSVTX; if (*name == '\0') { /* * Null component name refers to the directory itself. */ VN_HOLD(dvp); zp = dzp; dl = NULL; error = 0; } else { /* possible VN_HOLD(zp) */ if (error = zfs_dirent_lock(&dl, dzp, name, &zp, 0)) { if (strcmp(name, "..") == 0) error = EISDIR; ZFS_EXIT(zfsvfs); return (error); } } zoid = zp ? zp->z_id : -1ULL; if (zp == NULL) { /* * Create a new file object and update the directory * to reference it. */ if (error = zfs_zaccess(dzp, ACE_ADD_FILE, cr)) { goto out; } /* * We only support the creation of regular files in * extended attribute directories. */ if ((dzp->z_phys->zp_flags & ZFS_XATTR) && (vap->va_type != VREG)) { error = EINVAL; goto out; } tx = dmu_tx_create(os); dmu_tx_hold_bonus(tx, DMU_NEW_OBJECT); dmu_tx_hold_bonus(tx, dzp->z_id); dmu_tx_hold_zap(tx, dzp->z_id, TRUE, name); if (dzp->z_phys->zp_flags & ZFS_INHERIT_ACE) dmu_tx_hold_write(tx, DMU_NEW_OBJECT, 0, SPA_MAXBLOCKSIZE); error = dmu_tx_assign(tx, zfsvfs->z_assign); if (error) { zfs_dirent_unlock(dl); if (error == ERESTART && zfsvfs->z_assign == TXG_NOWAIT) { dmu_tx_wait(tx); dmu_tx_abort(tx); goto top; } dmu_tx_abort(tx); ZFS_EXIT(zfsvfs); return (error); } zfs_mknode(dzp, vap, &zoid, tx, cr, 0, &zp, 0); ASSERT(zp->z_id == zoid); (void) zfs_link_create(dl, zp, tx, ZNEW); zfs_log_create(zilog, tx, TX_CREATE, dzp, zp, name); dmu_tx_commit(tx); } else { /* * A directory entry already exists for this name. */ /* * Can't truncate an existing file if in exclusive mode. */ if (excl == EXCL) { error = EEXIST; goto out; } /* * Can't open a directory for writing. */ if ((ZTOV(zp)->v_type == VDIR) && (mode & S_IWRITE)) { error = EISDIR; goto out; } /* * Verify requested access to file. */ if (mode && (error = zfs_zaccess_rwx(zp, mode, cr))) { goto out; } mutex_enter(&dzp->z_lock); dzp->z_seq++; mutex_exit(&dzp->z_lock); /* * Truncate regular files if requested. */ if ((ZTOV(zp)->v_type == VREG) && (zp->z_phys->zp_size != 0) && (vap->va_mask & AT_SIZE) && (vap->va_size == 0)) { error = zfs_freesp(zp, 0, 0, mode, TRUE); if (error == ERESTART && zfsvfs->z_assign == TXG_NOWAIT) { /* NB: we already did dmu_tx_wait() */ zfs_dirent_unlock(dl); VN_RELE(ZTOV(zp)); goto top; } } } out: if (dl) zfs_dirent_unlock(dl); if (error) { if (zp) VN_RELE(ZTOV(zp)); } else { *vpp = ZTOV(zp); /* * If vnode is for a device return a specfs vnode instead. */ if (IS_DEVVP(*vpp)) { struct vnode *svp; svp = specvp(*vpp, (*vpp)->v_rdev, (*vpp)->v_type, cr); VN_RELE(*vpp); if (svp == NULL) { error = ENOSYS; } *vpp = svp; } } ZFS_EXIT(zfsvfs); return (error); } /* * Remove an entry from a directory. * * IN: dvp - vnode of directory to remove entry from. * name - name of entry to remove. * cr - credentials of caller. * * RETURN: 0 if success * error code if failure * * Timestamps: * dvp - ctime|mtime * vp - ctime (if nlink > 0) */ static int zfs_remove(vnode_t *dvp, char *name, cred_t *cr) { znode_t *zp, *dzp = VTOZ(dvp); znode_t *xzp = NULL; vnode_t *vp; zfsvfs_t *zfsvfs = dzp->z_zfsvfs; zilog_t *zilog = zfsvfs->z_log; uint64_t acl_obj, xattr_obj; zfs_dirlock_t *dl; dmu_tx_t *tx; int may_delete_now, delete_now = FALSE; int reaped; int error; ZFS_ENTER(zfsvfs); top: /* * Attempt to lock directory; fail if entry doesn't exist. */ if (error = zfs_dirent_lock(&dl, dzp, name, &zp, ZEXISTS)) { ZFS_EXIT(zfsvfs); return (error); } vp = ZTOV(zp); if (error = zfs_zaccess_delete(dzp, zp, cr)) { goto out; } /* * Need to use rmdir for removing directories. */ if (vp->v_type == VDIR) { error = EPERM; goto out; } vnevent_remove(vp); dnlc_remove(dvp, name); mutex_enter(&vp->v_lock); may_delete_now = vp->v_count == 1 && !vn_has_cached_data(vp); mutex_exit(&vp->v_lock); /* * We may delete the znode now, or we may put it on the delete queue; * it depends on whether we're the last link, and on whether there are * other holds on the vnode. So we dmu_tx_hold() the right things to * allow for either case. */ tx = dmu_tx_create(zfsvfs->z_os); dmu_tx_hold_zap(tx, dzp->z_id, FALSE, name); dmu_tx_hold_bonus(tx, zp->z_id); if (may_delete_now) dmu_tx_hold_free(tx, zp->z_id, 0, DMU_OBJECT_END); /* are there any extended attributes? */ if ((xattr_obj = zp->z_phys->zp_xattr) != 0) { /* * XXX - There is a possibility that the delete * of the parent file could succeed, but then we get * an ENOSPC when we try to delete the xattrs... * so we would need to re-try the deletes periodically */ /* XXX - do we need this if we are deleting? */ dmu_tx_hold_bonus(tx, xattr_obj); } /* are there any additional acls */ if ((acl_obj = zp->z_phys->zp_acl.z_acl_extern_obj) != 0 && may_delete_now) dmu_tx_hold_free(tx, acl_obj, 0, DMU_OBJECT_END); /* charge as an update -- would be nice not to charge at all */ dmu_tx_hold_zap(tx, zfsvfs->z_dqueue, FALSE, NULL); error = dmu_tx_assign(tx, zfsvfs->z_assign); if (error) { zfs_dirent_unlock(dl); VN_RELE(vp); if (error == ERESTART && zfsvfs->z_assign == TXG_NOWAIT) { dmu_tx_wait(tx); dmu_tx_abort(tx); goto top; } dmu_tx_abort(tx); ZFS_EXIT(zfsvfs); return (error); } /* * Remove the directory entry. */ error = zfs_link_destroy(dl, zp, tx, 0, &reaped); if (error) { dmu_tx_commit(tx); goto out; } if (reaped) { mutex_enter(&vp->v_lock); delete_now = may_delete_now && vp->v_count == 1 && !vn_has_cached_data(vp) && zp->z_phys->zp_xattr == xattr_obj && zp->z_phys->zp_acl.z_acl_extern_obj == acl_obj; mutex_exit(&vp->v_lock); } if (delete_now) { if (zp->z_phys->zp_xattr) { error = zfs_zget(zfsvfs, zp->z_phys->zp_xattr, &xzp); ASSERT3U(error, ==, 0); ASSERT3U(xzp->z_phys->zp_links, ==, 2); dmu_buf_will_dirty(xzp->z_dbuf, tx); mutex_enter(&xzp->z_lock); xzp->z_reap = 1; xzp->z_phys->zp_links = 0; mutex_exit(&xzp->z_lock); zfs_dq_add(xzp, tx); zp->z_phys->zp_xattr = 0; /* probably unnecessary */ } mutex_enter(&zp->z_lock); mutex_enter(&vp->v_lock); vp->v_count--; ASSERT3U(vp->v_count, ==, 0); mutex_exit(&vp->v_lock); mutex_exit(&zp->z_lock); zfs_znode_delete(zp, tx); VFS_RELE(zfsvfs->z_vfs); } else if (reaped) { zfs_dq_add(zp, tx); } zfs_log_remove(zilog, tx, TX_REMOVE, dzp, name); dmu_tx_commit(tx); out: zfs_dirent_unlock(dl); if (!delete_now) { VN_RELE(vp); } else if (xzp) { /* this rele delayed to prevent nesting transactions */ VN_RELE(ZTOV(xzp)); } ZFS_EXIT(zfsvfs); return (error); } /* * Create a new directory and insert it into dvp using the name * provided. Return a pointer to the inserted directory. * * IN: dvp - vnode of directory to add subdir to. * dirname - name of new directory. * vap - attributes of new directory. * cr - credentials of caller. * * OUT: vpp - vnode of created directory. * * RETURN: 0 if success * error code if failure * * Timestamps: * dvp - ctime|mtime updated * vp - ctime|mtime|atime updated */ static int zfs_mkdir(vnode_t *dvp, char *dirname, vattr_t *vap, vnode_t **vpp, cred_t *cr) { znode_t *zp, *dzp = VTOZ(dvp); zfsvfs_t *zfsvfs = dzp->z_zfsvfs; zilog_t *zilog = zfsvfs->z_log; zfs_dirlock_t *dl; uint64_t zoid = 0; dmu_tx_t *tx; int error; ASSERT(vap->va_type == VDIR); ZFS_ENTER(zfsvfs); if (dzp->z_phys->zp_flags & ZFS_XATTR) { ZFS_EXIT(zfsvfs); return (EINVAL); } top: *vpp = NULL; /* * First make sure the new directory doesn't exist. */ if (error = zfs_dirent_lock(&dl, dzp, dirname, &zp, ZNEW)) { ZFS_EXIT(zfsvfs); return (error); } if (error = zfs_zaccess(dzp, ACE_ADD_SUBDIRECTORY, cr)) { zfs_dirent_unlock(dl); ZFS_EXIT(zfsvfs); return (error); } /* * Add a new entry to the directory. */ tx = dmu_tx_create(zfsvfs->z_os); dmu_tx_hold_zap(tx, dzp->z_id, TRUE, dirname); dmu_tx_hold_zap(tx, DMU_NEW_OBJECT, FALSE, NULL); if (dzp->z_phys->zp_flags & ZFS_INHERIT_ACE) dmu_tx_hold_write(tx, DMU_NEW_OBJECT, 0, SPA_MAXBLOCKSIZE); error = dmu_tx_assign(tx, zfsvfs->z_assign); if (error) { zfs_dirent_unlock(dl); if (error == ERESTART && zfsvfs->z_assign == TXG_NOWAIT) { dmu_tx_wait(tx); dmu_tx_abort(tx); goto top; } dmu_tx_abort(tx); ZFS_EXIT(zfsvfs); return (error); } /* * Create new node. */ zfs_mknode(dzp, vap, &zoid, tx, cr, 0, &zp, 0); /* * Now put new name in parent dir. */ (void) zfs_link_create(dl, zp, tx, ZNEW); *vpp = ZTOV(zp); zfs_log_create(zilog, tx, TX_MKDIR, dzp, zp, dirname); dmu_tx_commit(tx); zfs_dirent_unlock(dl); ZFS_EXIT(zfsvfs); return (0); } /* * Remove a directory subdir entry. If the current working * directory is the same as the subdir to be removed, the * remove will fail. * * IN: dvp - vnode of directory to remove from. * name - name of directory to be removed. * cwd - vnode of current working directory. * cr - credentials of caller. * * RETURN: 0 if success * error code if failure * * Timestamps: * dvp - ctime|mtime updated */ static int zfs_rmdir(vnode_t *dvp, char *name, vnode_t *cwd, cred_t *cr) { znode_t *dzp = VTOZ(dvp); znode_t *zp; vnode_t *vp; zfsvfs_t *zfsvfs = dzp->z_zfsvfs; zilog_t *zilog = zfsvfs->z_log; zfs_dirlock_t *dl; dmu_tx_t *tx; int error; ZFS_ENTER(zfsvfs); top: zp = NULL; /* * Attempt to lock directory; fail if entry doesn't exist. */ if (error = zfs_dirent_lock(&dl, dzp, name, &zp, ZEXISTS)) { ZFS_EXIT(zfsvfs); return (error); } vp = ZTOV(zp); if (error = zfs_zaccess_delete(dzp, zp, cr)) { goto out; } if (vp->v_type != VDIR) { error = ENOTDIR; goto out; } if (vp == cwd) { error = EINVAL; goto out; } vnevent_rmdir(vp); /* * Grab a lock on the parent pointer make sure we play well * with the treewalk and directory rename code. */ rw_enter(&zp->z_parent_lock, RW_WRITER); tx = dmu_tx_create(zfsvfs->z_os); dmu_tx_hold_zap(tx, dzp->z_id, FALSE, name); dmu_tx_hold_bonus(tx, zp->z_id); dmu_tx_hold_zap(tx, zfsvfs->z_dqueue, FALSE, NULL); error = dmu_tx_assign(tx, zfsvfs->z_assign); if (error) { rw_exit(&zp->z_parent_lock); zfs_dirent_unlock(dl); VN_RELE(vp); if (error == ERESTART && zfsvfs->z_assign == TXG_NOWAIT) { dmu_tx_wait(tx); dmu_tx_abort(tx); goto top; } dmu_tx_abort(tx); ZFS_EXIT(zfsvfs); return (error); } error = zfs_link_destroy(dl, zp, tx, 0, NULL); if (error == 0) zfs_log_remove(zilog, tx, TX_RMDIR, dzp, name); dmu_tx_commit(tx); rw_exit(&zp->z_parent_lock); out: zfs_dirent_unlock(dl); VN_RELE(vp); ZFS_EXIT(zfsvfs); return (error); } /* * Read as many directory entries as will fit into the provided * buffer from the given directory cursor position (specified in * the uio structure. * * IN: vp - vnode of directory to read. * uio - structure supplying read location, range info, * and return buffer. * cr - credentials of caller. * * OUT: uio - updated offset and range, buffer filled. * eofp - set to true if end-of-file detected. * * RETURN: 0 if success * error code if failure * * Timestamps: * vp - atime updated * * Note that the low 4 bits of the cookie returned by zap is always zero. * This allows us to use the low range for "special" directory entries: * We use 0 for '.', and 1 for '..'. If this is the root of the filesystem, * we use the offset 2 for the '.zfs' directory. */ /* ARGSUSED */ static int zfs_readdir(vnode_t *vp, uio_t *uio, cred_t *cr, int *eofp) { znode_t *zp = VTOZ(vp); iovec_t *iovp; dirent64_t *odp; zfsvfs_t *zfsvfs = zp->z_zfsvfs; objset_t *os; caddr_t outbuf; size_t bufsize; zap_cursor_t zc; zap_attribute_t zap; uint_t bytes_wanted; ushort_t this_reclen; uint64_t offset; /* must be unsigned; checks for < 1 */ off64_t *next; int local_eof; int outcount; int error; uint8_t prefetch; ZFS_ENTER(zfsvfs); /* * If we are not given an eof variable, * use a local one. */ if (eofp == NULL) eofp = &local_eof; /* * Check for valid iov_len. */ if (uio->uio_iov->iov_len <= 0) { ZFS_EXIT(zfsvfs); return (EINVAL); } /* * Quit if directory has been removed (posix) */ if ((*eofp = zp->z_reap) != 0) { ZFS_EXIT(zfsvfs); return (0); } error = 0; os = zfsvfs->z_os; offset = uio->uio_loffset; prefetch = zp->z_zn_prefetch; /* * Initialize the iterator cursor. */ if (offset <= 3) { /* * Start iteration from the beginning of the directory. */ zap_cursor_init(&zc, os, zp->z_id); } else { /* * The offset is a serialized cursor. */ zap_cursor_init_serialized(&zc, os, zp->z_id, offset); } /* * Get space to change directory entries into fs independent format. */ iovp = uio->uio_iov; bytes_wanted = iovp->iov_len; if (uio->uio_segflg != UIO_SYSSPACE || uio->uio_iovcnt != 1) { bufsize = bytes_wanted; outbuf = kmem_alloc(bufsize, KM_SLEEP); odp = (struct dirent64 *)outbuf; } else { bufsize = bytes_wanted; odp = (struct dirent64 *)iovp->iov_base; } /* * Transform to file-system independent format */ outcount = 0; while (outcount < bytes_wanted) { /* * Special case `.', `..', and `.zfs'. */ if (offset == 0) { (void) strcpy(zap.za_name, "."); zap.za_first_integer = zp->z_id; this_reclen = DIRENT64_RECLEN(1); } else if (offset == 1) { (void) strcpy(zap.za_name, ".."); zap.za_first_integer = zp->z_phys->zp_parent; this_reclen = DIRENT64_RECLEN(2); } else if (offset == 2 && zfs_show_ctldir(zp)) { (void) strcpy(zap.za_name, ZFS_CTLDIR_NAME); zap.za_first_integer = ZFSCTL_INO_ROOT; this_reclen = DIRENT64_RECLEN(sizeof (ZFS_CTLDIR_NAME) - 1); } else { /* * Grab next entry. */ if (error = zap_cursor_retrieve(&zc, &zap)) { if ((*eofp = (error == ENOENT)) != 0) break; else goto update; } if (zap.za_integer_length != 8 || zap.za_num_integers != 1) { cmn_err(CE_WARN, "zap_readdir: bad directory " "entry, obj = %lld, offset = %lld\n", (u_longlong_t)zp->z_id, (u_longlong_t)offset); error = ENXIO; goto update; } this_reclen = DIRENT64_RECLEN(strlen(zap.za_name)); } /* * Will this entry fit in the buffer? */ if (outcount + this_reclen > bufsize) { /* * Did we manage to fit anything in the buffer? */ if (!outcount) { error = EINVAL; goto update; } break; } /* * Add this entry: */ odp->d_ino = (ino64_t)zap.za_first_integer; odp->d_reclen = (ushort_t)this_reclen; /* NOTE: d_off is the offset for the *next* entry */ next = &(odp->d_off); (void) strncpy(odp->d_name, zap.za_name, DIRENT64_NAMELEN(this_reclen)); outcount += this_reclen; odp = (dirent64_t *)((intptr_t)odp + this_reclen); ASSERT(outcount <= bufsize); /* Prefetch znode */ if (prefetch) dmu_prefetch(os, zap.za_first_integer, 0, 0); /* * Move to the next entry, fill in the previous offset. */ if (offset > 2 || (offset == 2 && !zfs_show_ctldir(zp))) { zap_cursor_advance(&zc); offset = zap_cursor_serialize(&zc); } else { offset += 1; } *next = offset; } zp->z_zn_prefetch = B_FALSE; /* a lookup will re-enable pre-fetching */ if (uio->uio_segflg == UIO_SYSSPACE && uio->uio_iovcnt == 1) { iovp->iov_base += outcount; iovp->iov_len -= outcount; uio->uio_resid -= outcount; } else if (error = uiomove(outbuf, (long)outcount, UIO_READ, uio)) { /* * Reset the pointer. */ offset = uio->uio_loffset; } update: zap_cursor_fini(&zc); if (uio->uio_segflg != UIO_SYSSPACE || uio->uio_iovcnt != 1) kmem_free(outbuf, bufsize); if (error == ENOENT) error = 0; ZFS_ACCESSTIME_STAMP(zfsvfs, zp); uio->uio_loffset = offset; ZFS_EXIT(zfsvfs); return (error); } static int zfs_fsync(vnode_t *vp, int syncflag, cred_t *cr) { znode_t *zp = VTOZ(vp); zfsvfs_t *zfsvfs = zp->z_zfsvfs; /* * Regardless of whether this is required for standards conformance, * this is the logical behavior when fsync() is called on a file with * dirty pages. We use B_ASYNC since the ZIL transactions are already * going to be pushed out as part of the zil_commit(). */ if (vn_has_cached_data(vp) && !(syncflag & FNODSYNC) && (vp->v_type == VREG) && !(IS_SWAPVP(vp))) (void) VOP_PUTPAGE(vp, (offset_t)0, (size_t)0, B_ASYNC, cr); ZFS_ENTER(zfsvfs); zil_commit(zfsvfs->z_log, zp->z_last_itx, zp->z_id); ZFS_EXIT(zfsvfs); return (0); } /* * Get the requested file attributes and place them in the provided * vattr structure. * * IN: vp - vnode of file. * vap - va_mask identifies requested attributes. * flags - [UNUSED] * cr - credentials of caller. * * OUT: vap - attribute values. * * RETURN: 0 (always succeeds) */ /* ARGSUSED */ static int zfs_getattr(vnode_t *vp, vattr_t *vap, int flags, cred_t *cr) { znode_t *zp = VTOZ(vp); zfsvfs_t *zfsvfs = zp->z_zfsvfs; znode_phys_t *pzp = zp->z_phys; int error; ZFS_ENTER(zfsvfs); /* * Return all attributes. It's cheaper to provide the answer * than to determine whether we were asked the question. */ mutex_enter(&zp->z_lock); vap->va_type = vp->v_type; vap->va_mode = pzp->zp_mode & MODEMASK; vap->va_uid = zp->z_phys->zp_uid; vap->va_gid = zp->z_phys->zp_gid; vap->va_fsid = zp->z_zfsvfs->z_vfs->vfs_dev; vap->va_nodeid = zp->z_id; vap->va_nlink = MIN(pzp->zp_links, UINT32_MAX); /* nlink_t limit! */ vap->va_size = pzp->zp_size; vap->va_rdev = vp->v_rdev; vap->va_seq = zp->z_seq; ZFS_TIME_DECODE(&vap->va_atime, pzp->zp_atime); ZFS_TIME_DECODE(&vap->va_mtime, pzp->zp_mtime); ZFS_TIME_DECODE(&vap->va_ctime, pzp->zp_ctime); /* * If ACL is trivial don't bother looking for ACE_READ_ATTRIBUTES. * Also, if we are the owner don't bother, since owner should * always be allowed to read basic attributes of file. */ if (!(zp->z_phys->zp_flags & ZFS_ACL_TRIVIAL) && (zp->z_phys->zp_uid != crgetuid(cr))) { if (error = zfs_zaccess(zp, ACE_READ_ATTRIBUTES, cr)) { mutex_exit(&zp->z_lock); ZFS_EXIT(zfsvfs); return (error); } } mutex_exit(&zp->z_lock); dmu_object_size_from_db(zp->z_dbuf, &vap->va_blksize, &vap->va_nblocks); if (zp->z_blksz == 0) { /* * Block size hasn't been set; suggest maximal I/O transfers. */ vap->va_blksize = zfsvfs->z_max_blksz; } ZFS_EXIT(zfsvfs); return (0); } /* * Set the file attributes to the values contained in the * vattr structure. * * IN: vp - vnode of file to be modified. * vap - new attribute values. * flags - ATTR_UTIME set if non-default time values provided. * cr - credentials of caller. * * RETURN: 0 if success * error code if failure * * Timestamps: * vp - ctime updated, mtime updated if size changed. */ /* ARGSUSED */ static int zfs_setattr(vnode_t *vp, vattr_t *vap, int flags, cred_t *cr, caller_context_t *ct) { struct znode *zp = VTOZ(vp); znode_phys_t *pzp = zp->z_phys; zfsvfs_t *zfsvfs = zp->z_zfsvfs; zilog_t *zilog = zfsvfs->z_log; dmu_tx_t *tx; vattr_t oldva; uint_t mask = vap->va_mask; uint_t saved_mask; int trim_mask = 0; uint64_t new_mode; znode_t *attrzp; int need_policy = FALSE; int err; if (mask == 0) return (0); if (mask & AT_NOSET) return (EINVAL); if (mask & AT_SIZE && vp->v_type == VDIR) return (EISDIR); if (mask & AT_SIZE && vp->v_type != VREG && vp->v_type != VFIFO) return (EINVAL); ZFS_ENTER(zfsvfs); top: attrzp = NULL; if (zfsvfs->z_vfs->vfs_flag & VFS_RDONLY) { ZFS_EXIT(zfsvfs); return (EROFS); } /* * First validate permissions */ if (mask & AT_SIZE) { err = zfs_zaccess(zp, ACE_WRITE_DATA, cr); if (err) { ZFS_EXIT(zfsvfs); return (err); } /* * XXX - Note, we are not providing any open * mode flags here (like FNDELAY), so we may * block if there are locks present... this * should be addressed in openat(). */ do { err = zfs_freesp(zp, vap->va_size, 0, 0, FALSE); /* NB: we already did dmu_tx_wait() if necessary */ } while (err == ERESTART && zfsvfs->z_assign == TXG_NOWAIT); if (err) { ZFS_EXIT(zfsvfs); return (err); } } if (mask & (AT_ATIME|AT_MTIME)) need_policy = zfs_zaccess_v4_perm(zp, ACE_WRITE_ATTRIBUTES, cr); if (mask & (AT_UID|AT_GID)) { int idmask = (mask & (AT_UID|AT_GID)); int take_owner; int take_group; /* * NOTE: even if a new mode is being set, * we may clear S_ISUID/S_ISGID bits. */ if (!(mask & AT_MODE)) vap->va_mode = pzp->zp_mode; /* * Take ownership or chgrp to group we are a member of */ take_owner = (mask & AT_UID) && (vap->va_uid == crgetuid(cr)); take_group = (mask & AT_GID) && groupmember(vap->va_gid, cr); /* * If both AT_UID and AT_GID are set then take_owner and * take_group must both be set in order to allow taking * ownership. * * Otherwise, send the check through secpolicy_vnode_setattr() * */ if (((idmask == (AT_UID|AT_GID)) && take_owner && take_group) || ((idmask == AT_UID) && take_owner) || ((idmask == AT_GID) && take_group)) { if (zfs_zaccess_v4_perm(zp, ACE_WRITE_OWNER, cr) == 0) { /* * Remove setuid/setgid for non-privileged users */ secpolicy_setid_clear(vap, cr); trim_mask = (mask & (AT_UID|AT_GID)); } else { need_policy = TRUE; } } else { need_policy = TRUE; } } mutex_enter(&zp->z_lock); oldva.va_mode = pzp->zp_mode; oldva.va_uid = zp->z_phys->zp_uid; oldva.va_gid = zp->z_phys->zp_gid; mutex_exit(&zp->z_lock); if (mask & AT_MODE) { if (zfs_zaccess_v4_perm(zp, ACE_WRITE_ACL, cr) == 0) { err = secpolicy_setid_setsticky_clear(vp, vap, &oldva, cr); if (err) { ZFS_EXIT(zfsvfs); return (err); } trim_mask |= AT_MODE; } else { need_policy = TRUE; } } if (need_policy) { /* * If trim_mask is set then take ownership * has been granted or write_acl is present and user * has the ability to modify mode. In that case remove * UID|GID and or MODE from mask so that * secpolicy_vnode_setattr() doesn't revoke it. */ if (trim_mask) { saved_mask = vap->va_mask; vap->va_mask &= ~trim_mask; } err = secpolicy_vnode_setattr(cr, vp, vap, &oldva, flags, (int (*)(void *, int, cred_t *))zfs_zaccess_rwx, zp); if (err) { ZFS_EXIT(zfsvfs); return (err); } if (trim_mask) vap->va_mask |= saved_mask; } /* * secpolicy_vnode_setattr, or take ownership may have * changed va_mask */ mask = vap->va_mask; tx = dmu_tx_create(zfsvfs->z_os); dmu_tx_hold_bonus(tx, zp->z_id); if (mask & AT_MODE) { uint64_t pmode = pzp->zp_mode; new_mode = (pmode & S_IFMT) | (vap->va_mode & ~S_IFMT); if (zp->z_phys->zp_acl.z_acl_extern_obj) dmu_tx_hold_write(tx, pzp->zp_acl.z_acl_extern_obj, 0, SPA_MAXBLOCKSIZE); else dmu_tx_hold_write(tx, DMU_NEW_OBJECT, 0, ZFS_ACL_SIZE(MAX_ACL_SIZE)); } if ((mask & (AT_UID | AT_GID)) && zp->z_phys->zp_xattr != 0) { err = zfs_zget(zp->z_zfsvfs, zp->z_phys->zp_xattr, &attrzp); if (err) { dmu_tx_abort(tx); ZFS_EXIT(zfsvfs); return (err); } dmu_tx_hold_bonus(tx, attrzp->z_id); } err = dmu_tx_assign(tx, zfsvfs->z_assign); if (err) { if (attrzp) VN_RELE(ZTOV(attrzp)); if (err == ERESTART && zfsvfs->z_assign == TXG_NOWAIT) { dmu_tx_wait(tx); dmu_tx_abort(tx); goto top; } dmu_tx_abort(tx); ZFS_EXIT(zfsvfs); return (err); } dmu_buf_will_dirty(zp->z_dbuf, tx); /* * Set each attribute requested. * We group settings according to the locks they need to acquire. * * Note: you cannot set ctime directly, although it will be * updated as a side-effect of calling this function. */ mutex_enter(&zp->z_lock); if (mask & AT_MODE) { err = zfs_acl_chmod_setattr(zp, new_mode, tx); ASSERT3U(err, ==, 0); } if (attrzp) mutex_enter(&attrzp->z_lock); if (mask & AT_UID) { zp->z_phys->zp_uid = (uint64_t)vap->va_uid; if (attrzp) { attrzp->z_phys->zp_uid = (uint64_t)vap->va_uid; } } if (mask & AT_GID) { zp->z_phys->zp_gid = (uint64_t)vap->va_gid; if (attrzp) attrzp->z_phys->zp_gid = (uint64_t)vap->va_gid; } if (attrzp) mutex_exit(&attrzp->z_lock); if (mask & AT_ATIME) ZFS_TIME_ENCODE(&vap->va_atime, pzp->zp_atime); if (mask & AT_MTIME) ZFS_TIME_ENCODE(&vap->va_mtime, pzp->zp_mtime); if (mask & AT_SIZE) zfs_time_stamper_locked(zp, CONTENT_MODIFIED, tx); else if (mask != 0) zfs_time_stamper_locked(zp, STATE_CHANGED, tx); if (mask != 0) zfs_log_setattr(zilog, tx, TX_SETATTR, zp, vap, mask); mutex_exit(&zp->z_lock); if (attrzp) VN_RELE(ZTOV(attrzp)); dmu_tx_commit(tx); ZFS_EXIT(zfsvfs); return (err); } /* * Search back through the directory tree, using the ".." entries. * Lock each directory in the chain to prevent concurrent renames. * Fail any attempt to move a directory into one of its own descendants. * XXX - z_parent_lock can overlap with map or grow locks */ typedef struct zfs_zlock { krwlock_t *zl_rwlock; /* lock we acquired */ znode_t *zl_znode; /* znode we held */ struct zfs_zlock *zl_next; /* next in list */ } zfs_zlock_t; static int zfs_rename_lock(znode_t *szp, znode_t *tdzp, znode_t *sdzp, zfs_zlock_t **zlpp) { zfs_zlock_t *zl; znode_t *zp = tdzp; uint64_t rootid = zp->z_zfsvfs->z_root; uint64_t *oidp = &zp->z_id; krwlock_t *rwlp = &szp->z_parent_lock; krw_t rw = RW_WRITER; /* * First pass write-locks szp and compares to zp->z_id. * Later passes read-lock zp and compare to zp->z_parent. */ do { zl = kmem_alloc(sizeof (*zl), KM_SLEEP); zl->zl_rwlock = rwlp; zl->zl_znode = NULL; zl->zl_next = *zlpp; *zlpp = zl; rw_enter(rwlp, rw); if (*oidp == szp->z_id) /* We're a descendant of szp */ return (EINVAL); if (*oidp == rootid) /* We've hit the top */ return (0); if (rw == RW_READER) { /* i.e. not the first pass */ int error = zfs_zget(zp->z_zfsvfs, *oidp, &zp); if (error) return (error); zl->zl_znode = zp; } oidp = &zp->z_phys->zp_parent; rwlp = &zp->z_parent_lock; rw = RW_READER; } while (zp->z_id != sdzp->z_id); return (0); } /* * Drop locks and release vnodes that were held by zfs_rename_lock(). */ static void zfs_rename_unlock(zfs_zlock_t **zlpp) { zfs_zlock_t *zl; while ((zl = *zlpp) != NULL) { if (zl->zl_znode != NULL) VN_RELE(ZTOV(zl->zl_znode)); rw_exit(zl->zl_rwlock); *zlpp = zl->zl_next; kmem_free(zl, sizeof (*zl)); } } /* * Move an entry from the provided source directory to the target * directory. Change the entry name as indicated. * * IN: sdvp - Source directory containing the "old entry". * snm - Old entry name. * tdvp - Target directory to contain the "new entry". * tnm - New entry name. * cr - credentials of caller. * * RETURN: 0 if success * error code if failure * * Timestamps: * sdvp,tdvp - ctime|mtime updated */ static int zfs_rename(vnode_t *sdvp, char *snm, vnode_t *tdvp, char *tnm, cred_t *cr) { znode_t *tdzp, *szp, *tzp; znode_t *sdzp = VTOZ(sdvp); zfsvfs_t *zfsvfs = sdzp->z_zfsvfs; zilog_t *zilog = zfsvfs->z_log; vnode_t *realvp; zfs_dirlock_t *sdl, *tdl; dmu_tx_t *tx; zfs_zlock_t *zl; int cmp, serr, terr, error; ZFS_ENTER(zfsvfs); /* * Make sure we have the real vp for the target directory. */ if (VOP_REALVP(tdvp, &realvp) == 0) tdvp = realvp; if (tdvp->v_vfsp != sdvp->v_vfsp) { ZFS_EXIT(zfsvfs); return (EXDEV); } tdzp = VTOZ(tdvp); top: szp = NULL; tzp = NULL; zl = NULL; /* * This is to prevent the creation of links into attribute space * by renaming a linked file into/outof an attribute directory. * See the comment in zfs_link() for why this is considered bad. */ if ((tdzp->z_phys->zp_flags & ZFS_XATTR) != (sdzp->z_phys->zp_flags & ZFS_XATTR)) { ZFS_EXIT(zfsvfs); return (EINVAL); } /* * Lock source and target directory entries. To prevent deadlock, * a lock ordering must be defined. We lock the directory with * the smallest object id first, or if it's a tie, the one with * the lexically first name. */ if (sdzp->z_id < tdzp->z_id) { cmp = -1; } else if (sdzp->z_id > tdzp->z_id) { cmp = 1; } else { cmp = strcmp(snm, tnm); if (cmp == 0) { /* * POSIX: "If the old argument and the new argument * both refer to links to the same existing file, * the rename() function shall return successfully * and perform no other action." */ ZFS_EXIT(zfsvfs); return (0); } } if (cmp < 0) { serr = zfs_dirent_lock(&sdl, sdzp, snm, &szp, ZEXISTS); terr = zfs_dirent_lock(&tdl, tdzp, tnm, &tzp, 0); } else { terr = zfs_dirent_lock(&tdl, tdzp, tnm, &tzp, 0); serr = zfs_dirent_lock(&sdl, sdzp, snm, &szp, ZEXISTS); } if (serr) { /* * Source entry invalid or not there. */ if (!terr) { zfs_dirent_unlock(tdl); if (tzp) VN_RELE(ZTOV(tzp)); } if (strcmp(snm, "..") == 0) serr = EINVAL; ZFS_EXIT(zfsvfs); return (serr); } if (terr) { zfs_dirent_unlock(sdl); VN_RELE(ZTOV(szp)); if (strcmp(tnm, "..") == 0) terr = EINVAL; ZFS_EXIT(zfsvfs); return (terr); } /* * Must have write access at the source to remove the old entry * and write access at the target to create the new entry. * Note that if target and source are the same, this can be * done in a single check. */ if (error = zfs_zaccess_rename(sdzp, szp, tdzp, tzp, cr)) goto out; if (ZTOV(szp)->v_type == VDIR) { /* * Check to make sure rename is valid. * Can't do a move like this: /usr/a/b to /usr/a/b/c/d */ if (error = zfs_rename_lock(szp, tdzp, sdzp, &zl)) goto out; } /* * Does target exist? */ if (tzp) { /* * Source and target must be the same type. */ if (ZTOV(szp)->v_type == VDIR) { if (ZTOV(tzp)->v_type != VDIR) { error = ENOTDIR; goto out; } } else { if (ZTOV(tzp)->v_type == VDIR) { error = EISDIR; goto out; } } /* * POSIX dictates that when the source and target * entries refer to the same file object, rename * must do nothing and exit without error. */ if (szp->z_id == tzp->z_id) { error = 0; goto out; } } vnevent_rename_src(ZTOV(szp)); if (tzp) vnevent_rename_dest(ZTOV(tzp)); tx = dmu_tx_create(zfsvfs->z_os); dmu_tx_hold_bonus(tx, szp->z_id); /* nlink changes */ dmu_tx_hold_bonus(tx, sdzp->z_id); /* nlink changes */ dmu_tx_hold_zap(tx, sdzp->z_id, FALSE, snm); dmu_tx_hold_zap(tx, tdzp->z_id, TRUE, tnm); if (sdzp != tdzp) dmu_tx_hold_bonus(tx, tdzp->z_id); /* nlink changes */ if (tzp) dmu_tx_hold_bonus(tx, tzp->z_id); /* parent changes */ dmu_tx_hold_zap(tx, zfsvfs->z_dqueue, FALSE, NULL); error = dmu_tx_assign(tx, zfsvfs->z_assign); if (error) { if (zl != NULL) zfs_rename_unlock(&zl); zfs_dirent_unlock(sdl); zfs_dirent_unlock(tdl); VN_RELE(ZTOV(szp)); if (tzp) VN_RELE(ZTOV(tzp)); if (error == ERESTART && zfsvfs->z_assign == TXG_NOWAIT) { dmu_tx_wait(tx); dmu_tx_abort(tx); goto top; } dmu_tx_abort(tx); ZFS_EXIT(zfsvfs); return (error); } if (tzp) /* Attempt to remove the existing target */ error = zfs_link_destroy(tdl, tzp, tx, 0, NULL); if (error == 0) { error = zfs_link_create(tdl, szp, tx, ZRENAMING); if (error == 0) { error = zfs_link_destroy(sdl, szp, tx, ZRENAMING, NULL); ASSERT(error == 0); zfs_log_rename(zilog, tx, TX_RENAME, sdzp, sdl->dl_name, tdzp, tdl->dl_name, szp); } } dmu_tx_commit(tx); out: if (zl != NULL) zfs_rename_unlock(&zl); zfs_dirent_unlock(sdl); zfs_dirent_unlock(tdl); VN_RELE(ZTOV(szp)); if (tzp) VN_RELE(ZTOV(tzp)); ZFS_EXIT(zfsvfs); return (error); } /* * Insert the indicated symbolic reference entry into the directory. * * IN: dvp - Directory to contain new symbolic link. * link - Name for new symlink entry. * vap - Attributes of new entry. * target - Target path of new symlink. * cr - credentials of caller. * * RETURN: 0 if success * error code if failure * * Timestamps: * dvp - ctime|mtime updated */ static int zfs_symlink(vnode_t *dvp, char *name, vattr_t *vap, char *link, cred_t *cr) { znode_t *zp, *dzp = VTOZ(dvp); zfs_dirlock_t *dl; dmu_tx_t *tx; zfsvfs_t *zfsvfs = dzp->z_zfsvfs; zilog_t *zilog = zfsvfs->z_log; uint64_t zoid; int len = strlen(link); int error; ASSERT(vap->va_type == VLNK); ZFS_ENTER(zfsvfs); top: if (error = zfs_zaccess(dzp, ACE_ADD_FILE, cr)) { ZFS_EXIT(zfsvfs); return (error); } if (len > MAXPATHLEN) { ZFS_EXIT(zfsvfs); return (ENAMETOOLONG); } /* * Attempt to lock directory; fail if entry already exists. */ if (error = zfs_dirent_lock(&dl, dzp, name, &zp, ZNEW)) { ZFS_EXIT(zfsvfs); return (error); } tx = dmu_tx_create(zfsvfs->z_os); dmu_tx_hold_write(tx, DMU_NEW_OBJECT, 0, MAX(1, len)); dmu_tx_hold_bonus(tx, dzp->z_id); dmu_tx_hold_zap(tx, dzp->z_id, TRUE, name); if (dzp->z_phys->zp_flags & ZFS_INHERIT_ACE) dmu_tx_hold_write(tx, DMU_NEW_OBJECT, 0, SPA_MAXBLOCKSIZE); error = dmu_tx_assign(tx, zfsvfs->z_assign); if (error) { zfs_dirent_unlock(dl); if (error == ERESTART && zfsvfs->z_assign == TXG_NOWAIT) { dmu_tx_wait(tx); dmu_tx_abort(tx); goto top; } dmu_tx_abort(tx); ZFS_EXIT(zfsvfs); return (error); } dmu_buf_will_dirty(dzp->z_dbuf, tx); /* * Create a new object for the symlink. * Put the link content into bonus buffer if it will fit; * otherwise, store it just like any other file data. */ zoid = 0; if (sizeof (znode_phys_t) + len <= dmu_bonus_max()) { zfs_mknode(dzp, vap, &zoid, tx, cr, 0, &zp, len); if (len != 0) bcopy(link, zp->z_phys + 1, len); } else { dmu_buf_t *dbp; zfs_mknode(dzp, vap, &zoid, tx, cr, 0, &zp, 0); /* * Nothing can access the znode yet so no locking needed * for growing the znode's blocksize. */ zfs_grow_blocksize(zp, len, tx); VERIFY(0 == dmu_buf_hold(zfsvfs->z_os, zoid, 0, FTAG, &dbp)); dmu_buf_will_dirty(dbp, tx); ASSERT3U(len, <=, dbp->db_size); bcopy(link, dbp->db_data, len); dmu_buf_rele(dbp, FTAG); } zp->z_phys->zp_size = len; /* * Insert the new object into the directory. */ (void) zfs_link_create(dl, zp, tx, ZNEW); out: if (error == 0) zfs_log_symlink(zilog, tx, TX_SYMLINK, dzp, zp, name, link); dmu_tx_commit(tx); zfs_dirent_unlock(dl); VN_RELE(ZTOV(zp)); ZFS_EXIT(zfsvfs); return (error); } /* * Return, in the buffer contained in the provided uio structure, * the symbolic path referred to by vp. * * IN: vp - vnode of symbolic link. * uoip - structure to contain the link path. * cr - credentials of caller. * * OUT: uio - structure to contain the link path. * * RETURN: 0 if success * error code if failure * * Timestamps: * vp - atime updated */ /* ARGSUSED */ static int zfs_readlink(vnode_t *vp, uio_t *uio, cred_t *cr) { znode_t *zp = VTOZ(vp); zfsvfs_t *zfsvfs = zp->z_zfsvfs; size_t bufsz; int error; ZFS_ENTER(zfsvfs); bufsz = (size_t)zp->z_phys->zp_size; if (bufsz + sizeof (znode_phys_t) <= zp->z_dbuf->db_size) { error = uiomove(zp->z_phys + 1, MIN((size_t)bufsz, uio->uio_resid), UIO_READ, uio); } else { dmu_buf_t *dbp; error = dmu_buf_hold(zfsvfs->z_os, zp->z_id, 0, FTAG, &dbp); if (error) { ZFS_EXIT(zfsvfs); return (error); } error = uiomove(dbp->db_data, MIN((size_t)bufsz, uio->uio_resid), UIO_READ, uio); dmu_buf_rele(dbp, FTAG); } ZFS_ACCESSTIME_STAMP(zfsvfs, zp); ZFS_EXIT(zfsvfs); return (error); } /* * Insert a new entry into directory tdvp referencing svp. * * IN: tdvp - Directory to contain new entry. * svp - vnode of new entry. * name - name of new entry. * cr - credentials of caller. * * RETURN: 0 if success * error code if failure * * Timestamps: * tdvp - ctime|mtime updated * svp - ctime updated */ /* ARGSUSED */ static int zfs_link(vnode_t *tdvp, vnode_t *svp, char *name, cred_t *cr) { znode_t *dzp = VTOZ(tdvp); znode_t *tzp, *szp; zfsvfs_t *zfsvfs = dzp->z_zfsvfs; zilog_t *zilog = zfsvfs->z_log; zfs_dirlock_t *dl; dmu_tx_t *tx; vnode_t *realvp; int error; ASSERT(tdvp->v_type == VDIR); ZFS_ENTER(zfsvfs); if (VOP_REALVP(svp, &realvp) == 0) svp = realvp; if (svp->v_vfsp != tdvp->v_vfsp) { ZFS_EXIT(zfsvfs); return (EXDEV); } szp = VTOZ(svp); top: /* * We do not support links between attributes and non-attributes * because of the potential security risk of creating links * into "normal" file space in order to circumvent restrictions * imposed in attribute space. */ if ((szp->z_phys->zp_flags & ZFS_XATTR) != (dzp->z_phys->zp_flags & ZFS_XATTR)) { ZFS_EXIT(zfsvfs); return (EINVAL); } /* * POSIX dictates that we return EPERM here. * Better choices include ENOTSUP or EISDIR. */ if (svp->v_type == VDIR) { ZFS_EXIT(zfsvfs); return (EPERM); } if ((uid_t)szp->z_phys->zp_uid != crgetuid(cr) && secpolicy_basic_link(cr) != 0) { ZFS_EXIT(zfsvfs); return (EPERM); } if (error = zfs_zaccess(dzp, ACE_ADD_FILE, cr)) { ZFS_EXIT(zfsvfs); return (error); } /* * Attempt to lock directory; fail if entry already exists. */ if (error = zfs_dirent_lock(&dl, dzp, name, &tzp, ZNEW)) { ZFS_EXIT(zfsvfs); return (error); } tx = dmu_tx_create(zfsvfs->z_os); dmu_tx_hold_bonus(tx, szp->z_id); dmu_tx_hold_zap(tx, dzp->z_id, TRUE, name); error = dmu_tx_assign(tx, zfsvfs->z_assign); if (error) { zfs_dirent_unlock(dl); if (error == ERESTART && zfsvfs->z_assign == TXG_NOWAIT) { dmu_tx_wait(tx); dmu_tx_abort(tx); goto top; } dmu_tx_abort(tx); ZFS_EXIT(zfsvfs); return (error); } error = zfs_link_create(dl, szp, tx, 0); if (error == 0) zfs_log_link(zilog, tx, TX_LINK, dzp, szp, name); dmu_tx_commit(tx); zfs_dirent_unlock(dl); ZFS_EXIT(zfsvfs); return (error); } /* * zfs_null_putapage() is used when the file system has been force * unmounted. It just drops the pages. */ /* ARGSUSED */ static int zfs_null_putapage(vnode_t *vp, page_t *pp, u_offset_t *offp, size_t *lenp, int flags, cred_t *cr) { pvn_write_done(pp, B_INVAL|B_FORCE|B_ERROR); return (0); } /* * Push a page out to disk, klustering if possible. * * IN: vp - file to push page to. * pp - page to push. * flags - additional flags. * cr - credentials of caller. * * OUT: offp - start of range pushed. * lenp - len of range pushed. * * RETURN: 0 if success * error code if failure * * NOTE: callers must have locked the page to be pushed. On * exit, the page (and all other pages in the kluster) must be * unlocked. */ /* ARGSUSED */ static int zfs_putapage(vnode_t *vp, page_t *pp, u_offset_t *offp, size_t *lenp, int flags, cred_t *cr) { znode_t *zp = VTOZ(vp); zfsvfs_t *zfsvfs = zp->z_zfsvfs; zilog_t *zilog = zfsvfs->z_log; dmu_tx_t *tx; rl_t *rl; u_offset_t off, koff; size_t len, klen; int err; off = pp->p_offset; len = PAGESIZE; /* * If our blocksize is bigger than the page size, try to kluster * muiltiple pages so that we write a full block (thus avoiding * a read-modify-write). */ if (zp->z_blksz > PAGESIZE) { uint64_t filesz = zp->z_phys->zp_size; if (!ISP2(zp->z_blksz)) { /* Only one block in the file. */ klen = P2ROUNDUP((ulong_t)zp->z_blksz, PAGESIZE); koff = 0; } else { klen = zp->z_blksz; koff = P2ALIGN(off, (u_offset_t)klen); } ASSERT(koff <= filesz); if (koff + klen > filesz) klen = P2ROUNDUP(filesz - koff, (uint64_t)PAGESIZE); pp = pvn_write_kluster(vp, pp, &off, &len, koff, klen, flags); } ASSERT3U(btop(len), ==, btopr(len)); top: rl = zfs_range_lock(zp, off, len, RL_WRITER); /* * Can't push pages past end-of-file. */ if (off >= zp->z_phys->zp_size) { /* discard all pages */ flags |= B_INVAL; err = 0; goto out; } else if (off + len > zp->z_phys->zp_size) { int npages = btopr(zp->z_phys->zp_size - off); page_t *trunc; page_list_break(&pp, &trunc, npages); /* discard pages past end of file */ if (trunc) pvn_write_done(trunc, B_INVAL | flags); len = zp->z_phys->zp_size - off; } tx = dmu_tx_create(zfsvfs->z_os); dmu_tx_hold_write(tx, zp->z_id, off, len); dmu_tx_hold_bonus(tx, zp->z_id); err = dmu_tx_assign(tx, zfsvfs->z_assign); if (err != 0) { if (err == ERESTART && zfsvfs->z_assign == TXG_NOWAIT) { zfs_range_unlock(rl); dmu_tx_wait(tx); dmu_tx_abort(tx); err = 0; goto top; } dmu_tx_abort(tx); goto out; } if (zp->z_blksz <= PAGESIZE) { caddr_t va = ppmapin(pp, PROT_READ, (caddr_t)-1); ASSERT3U(len, <=, PAGESIZE); dmu_write(zfsvfs->z_os, zp->z_id, off, len, va, tx); ppmapout(va); } else { err = dmu_write_pages(zfsvfs->z_os, zp->z_id, off, len, pp, tx); } if (err == 0) { zfs_time_stamper(zp, CONTENT_MODIFIED, tx); (void) zfs_log_write( zilog, tx, TX_WRITE, zp, off, len, 0, NULL); dmu_tx_commit(tx); } out: zfs_range_unlock(rl); pvn_write_done(pp, (err ? B_ERROR : 0) | B_WRITE | flags); if (offp) *offp = off; if (lenp) *lenp = len; return (err); } /* * Copy the portion of the file indicated from pages into the file. * The pages are stored in a page list attached to the files vnode. * * IN: vp - vnode of file to push page data to. * off - position in file to put data. * len - amount of data to write. * flags - flags to control the operation. * cr - credentials of caller. * * RETURN: 0 if success * error code if failure * * Timestamps: * vp - ctime|mtime updated */ static int zfs_putpage(vnode_t *vp, offset_t off, size_t len, int flags, cred_t *cr) { znode_t *zp = VTOZ(vp); zfsvfs_t *zfsvfs = zp->z_zfsvfs; page_t *pp; size_t io_len; u_offset_t io_off; uint64_t filesz; int error = 0; ZFS_ENTER(zfsvfs); ASSERT(zp->z_dbuf_held && zp->z_phys); if (len == 0) { /* * Search the entire vp list for pages >= off. */ error = pvn_vplist_dirty(vp, (u_offset_t)off, zfs_putapage, flags, cr); goto out; } filesz = zp->z_phys->zp_size; /* get consistent copy of zp_size */ if (off > filesz) { /* past end of file */ ZFS_EXIT(zfsvfs); return (0); } len = MIN(len, filesz - off); for (io_off = off; io_off < off + len; io_off += io_len) { if ((flags & B_INVAL) || ((flags & B_ASYNC) == 0)) { pp = page_lookup(vp, io_off, (flags & (B_INVAL | B_FREE)) ? SE_EXCL : SE_SHARED); } else { pp = page_lookup_nowait(vp, io_off, (flags & B_FREE) ? SE_EXCL : SE_SHARED); } if (pp != NULL && pvn_getdirty(pp, flags)) { int err; /* * Found a dirty page to push */ err = zfs_putapage(vp, pp, &io_off, &io_len, flags, cr); if (err) error = err; } else { io_len = PAGESIZE; } } out: if ((flags & B_ASYNC) == 0) zil_commit(zfsvfs->z_log, UINT64_MAX, zp->z_id); ZFS_EXIT(zfsvfs); return (error); } void zfs_inactive(vnode_t *vp, cred_t *cr) { znode_t *zp = VTOZ(vp); zfsvfs_t *zfsvfs = zp->z_zfsvfs; int error; rw_enter(&zfsvfs->z_um_lock, RW_READER); if (zfsvfs->z_unmounted2) { ASSERT(zp->z_dbuf_held == 0); if (vn_has_cached_data(vp)) { (void) pvn_vplist_dirty(vp, 0, zfs_null_putapage, B_INVAL, cr); } mutex_enter(&zp->z_lock); vp->v_count = 0; /* count arrives as 1 */ if (zp->z_dbuf == NULL) { mutex_exit(&zp->z_lock); zfs_znode_free(zp); } else { mutex_exit(&zp->z_lock); } rw_exit(&zfsvfs->z_um_lock); VFS_RELE(zfsvfs->z_vfs); return; } /* * Attempt to push any data in the page cache. If this fails * we will get kicked out later in zfs_zinactive(). */ if (vn_has_cached_data(vp)) { (void) pvn_vplist_dirty(vp, 0, zfs_putapage, B_INVAL|B_ASYNC, cr); } if (zp->z_atime_dirty && zp->z_reap == 0) { dmu_tx_t *tx = dmu_tx_create(zfsvfs->z_os); dmu_tx_hold_bonus(tx, zp->z_id); error = dmu_tx_assign(tx, TXG_WAIT); if (error) { dmu_tx_abort(tx); } else { dmu_buf_will_dirty(zp->z_dbuf, tx); mutex_enter(&zp->z_lock); zp->z_atime_dirty = 0; mutex_exit(&zp->z_lock); dmu_tx_commit(tx); } } zfs_zinactive(zp); rw_exit(&zfsvfs->z_um_lock); } /* * Bounds-check the seek operation. * * IN: vp - vnode seeking within * ooff - old file offset * noffp - pointer to new file offset * * RETURN: 0 if success * EINVAL if new offset invalid */ /* ARGSUSED */ static int zfs_seek(vnode_t *vp, offset_t ooff, offset_t *noffp) { if (vp->v_type == VDIR) return (0); return ((*noffp < 0 || *noffp > MAXOFFSET_T) ? EINVAL : 0); } /* * Pre-filter the generic locking function to trap attempts to place * a mandatory lock on a memory mapped file. */ static int zfs_frlock(vnode_t *vp, int cmd, flock64_t *bfp, int flag, offset_t offset, flk_callback_t *flk_cbp, cred_t *cr) { znode_t *zp = VTOZ(vp); zfsvfs_t *zfsvfs = zp->z_zfsvfs; int error; ZFS_ENTER(zfsvfs); /* * We are following the UFS semantics with respect to mapcnt * here: If we see that the file is mapped already, then we will * return an error, but we don't worry about races between this * function and zfs_map(). */ if (zp->z_mapcnt > 0 && MANDMODE((mode_t)zp->z_phys->zp_mode)) { ZFS_EXIT(zfsvfs); return (EAGAIN); } error = fs_frlock(vp, cmd, bfp, flag, offset, flk_cbp, cr); ZFS_EXIT(zfsvfs); return (error); } /* * If we can't find a page in the cache, we will create a new page * and fill it with file data. For efficiency, we may try to fill * multiple pages at once (klustering). */ static int zfs_fillpage(vnode_t *vp, u_offset_t off, struct seg *seg, caddr_t addr, page_t *pl[], size_t plsz, enum seg_rw rw) { znode_t *zp = VTOZ(vp); page_t *pp, *cur_pp; objset_t *os = zp->z_zfsvfs->z_os; caddr_t va; u_offset_t io_off, total; uint64_t oid = zp->z_id; size_t io_len; uint64_t filesz; int err; /* * If we are only asking for a single page don't bother klustering. */ filesz = zp->z_phys->zp_size; /* get consistent copy of zp_size */ if (off >= filesz) return (EFAULT); if (plsz == PAGESIZE || zp->z_blksz <= PAGESIZE) { io_off = off; io_len = PAGESIZE; pp = page_create_va(vp, io_off, io_len, PG_WAIT, seg, addr); } else { /* * Try to fill a kluster of pages (a blocks worth). */ size_t klen; u_offset_t koff; if (!ISP2(zp->z_blksz)) { /* Only one block in the file. */ klen = P2ROUNDUP((ulong_t)zp->z_blksz, PAGESIZE); koff = 0; } else { klen = plsz; koff = P2ALIGN(off, (u_offset_t)klen); } ASSERT(koff <= filesz); if (koff + klen > filesz) klen = P2ROUNDUP(filesz, (uint64_t)PAGESIZE) - koff; ASSERT3U(off, >=, koff); ASSERT3U(off, <, koff + klen); pp = pvn_read_kluster(vp, off, seg, addr, &io_off, &io_len, koff, klen, 0); } if (pp == NULL) { /* * Some other thread entered the page before us. * Return to zfs_getpage to retry the lookup. */ *pl = NULL; return (0); } /* * Fill the pages in the kluster. */ cur_pp = pp; for (total = io_off + io_len; io_off < total; io_off += PAGESIZE) { ASSERT3U(io_off, ==, cur_pp->p_offset); va = ppmapin(cur_pp, PROT_READ | PROT_WRITE, (caddr_t)-1); err = dmu_read(os, oid, io_off, PAGESIZE, va); ppmapout(va); if (err) { /* On error, toss the entire kluster */ pvn_read_done(pp, B_ERROR); return (err); } cur_pp = cur_pp->p_next; } out: /* * Fill in the page list array from the kluster. If * there are too many pages in the kluster, return * as many pages as possible starting from the desired * offset `off'. * NOTE: the page list will always be null terminated. */ pvn_plist_init(pp, pl, plsz, off, io_len, rw); return (0); } /* * Return pointers to the pages for the file region [off, off + len] * in the pl array. If plsz is greater than len, this function may * also return page pointers from before or after the specified * region (i.e. some region [off', off' + plsz]). These additional * pages are only returned if they are already in the cache, or were * created as part of a klustered read. * * IN: vp - vnode of file to get data from. * off - position in file to get data from. * len - amount of data to retrieve. * plsz - length of provided page list. * seg - segment to obtain pages for. * addr - virtual address of fault. * rw - mode of created pages. * cr - credentials of caller. * * OUT: protp - protection mode of created pages. * pl - list of pages created. * * RETURN: 0 if success * error code if failure * * Timestamps: * vp - atime updated */ /* ARGSUSED */ static int zfs_getpage(vnode_t *vp, offset_t off, size_t len, uint_t *protp, page_t *pl[], size_t plsz, struct seg *seg, caddr_t addr, enum seg_rw rw, cred_t *cr) { znode_t *zp = VTOZ(vp); zfsvfs_t *zfsvfs = zp->z_zfsvfs; page_t *pp, **pl0 = pl; int need_unlock = 0, err = 0; offset_t orig_off; ZFS_ENTER(zfsvfs); if (protp) *protp = PROT_ALL; ASSERT(zp->z_dbuf_held && zp->z_phys); /* no faultahead (for now) */ if (pl == NULL) { ZFS_EXIT(zfsvfs); return (0); } /* can't fault past EOF */ if (off >= zp->z_phys->zp_size) { ZFS_EXIT(zfsvfs); return (EFAULT); } orig_off = off; /* * If we already own the lock, then we must be page faulting * in the middle of a write to this file (i.e., we are writing * to this file using data from a mapped region of the file). */ if (rw_owner(&zp->z_map_lock) != curthread) { rw_enter(&zp->z_map_lock, RW_WRITER); need_unlock = TRUE; } /* * Loop through the requested range [off, off + len] looking * for pages. If we don't find a page, we will need to create * a new page and fill it with data from the file. */ while (len > 0) { if (plsz < PAGESIZE) break; if (pp = page_lookup(vp, off, SE_SHARED)) { *pl++ = pp; off += PAGESIZE; addr += PAGESIZE; len -= PAGESIZE; plsz -= PAGESIZE; } else { err = zfs_fillpage(vp, off, seg, addr, pl, plsz, rw); if (err) goto out; /* * klustering may have changed our region * to be block aligned. */ if (((pp = *pl) != 0) && (off != pp->p_offset)) { int delta = off - pp->p_offset; len += delta; off -= delta; addr -= delta; } while (*pl) { pl++; off += PAGESIZE; addr += PAGESIZE; plsz -= PAGESIZE; if (len > PAGESIZE) len -= PAGESIZE; else len = 0; } } } /* * Fill out the page array with any pages already in the cache. */ while (plsz > 0) { pp = page_lookup_nowait(vp, off, SE_SHARED); if (pp == NULL) break; *pl++ = pp; off += PAGESIZE; plsz -= PAGESIZE; } ZFS_ACCESSTIME_STAMP(zfsvfs, zp); out: /* * We can't grab the range lock for the page as reader which would * stop truncation as this leads to deadlock. So we need to recheck * the file size. */ if (orig_off >= zp->z_phys->zp_size) err = EFAULT; if (err) { /* * Release any pages we have previously locked. */ while (pl > pl0) page_unlock(*--pl); } *pl = NULL; if (need_unlock) rw_exit(&zp->z_map_lock); ZFS_EXIT(zfsvfs); return (err); } /* * Request a memory map for a section of a file. This code interacts * with common code and the VM system as follows: * * common code calls mmap(), which ends up in smmap_common() * * this calls VOP_MAP(), which takes you into (say) zfs * * zfs_map() calls as_map(), passing segvn_create() as the callback * * segvn_create() creates the new segment and calls VOP_ADDMAP() * * zfs_addmap() updates z_mapcnt */ static int zfs_map(vnode_t *vp, offset_t off, struct as *as, caddr_t *addrp, size_t len, uchar_t prot, uchar_t maxprot, uint_t flags, cred_t *cr) { znode_t *zp = VTOZ(vp); zfsvfs_t *zfsvfs = zp->z_zfsvfs; segvn_crargs_t vn_a; int error; ZFS_ENTER(zfsvfs); if (vp->v_flag & VNOMAP) { ZFS_EXIT(zfsvfs); return (ENOSYS); } if (off < 0 || len > MAXOFFSET_T - off) { ZFS_EXIT(zfsvfs); return (ENXIO); } if (vp->v_type != VREG) { ZFS_EXIT(zfsvfs); return (ENODEV); } /* * If file is locked, disallow mapping. */ if (MANDMODE((mode_t)zp->z_phys->zp_mode) && vn_has_flocks(vp)) { ZFS_EXIT(zfsvfs); return (EAGAIN); } as_rangelock(as); if ((flags & MAP_FIXED) == 0) { map_addr(addrp, len, off, 1, flags); if (*addrp == NULL) { as_rangeunlock(as); ZFS_EXIT(zfsvfs); return (ENOMEM); } } else { /* * User specified address - blow away any previous mappings */ (void) as_unmap(as, *addrp, len); } vn_a.vp = vp; vn_a.offset = (u_offset_t)off; vn_a.type = flags & MAP_TYPE; vn_a.prot = prot; vn_a.maxprot = maxprot; vn_a.cred = cr; vn_a.amp = NULL; vn_a.flags = flags & ~MAP_TYPE; vn_a.szc = 0; vn_a.lgrp_mem_policy_flags = 0; error = as_map(as, *addrp, len, segvn_create, &vn_a); as_rangeunlock(as); ZFS_EXIT(zfsvfs); return (error); } /* ARGSUSED */ static int zfs_addmap(vnode_t *vp, offset_t off, struct as *as, caddr_t addr, size_t len, uchar_t prot, uchar_t maxprot, uint_t flags, cred_t *cr) { uint64_t pages = btopr(len); atomic_add_64(&VTOZ(vp)->z_mapcnt, pages); return (0); } /* * The reason we push dirty pages as part of zfs_delmap() is so that we get a * more accurate mtime for the associated file. Since we don't have a way of * detecting when the data was actually modified, we have to resort to * heuristics. If an explicit msync() is done, then we mark the mtime when the * last page is pushed. The problem occurs when the msync() call is omitted, * which by far the most common case: * * open() * mmap() * * munmap() * close() *