From 872e8d26978a8e1caa1ca7d931db7f95d987a3e7 Mon Sep 17 00:00:00 2001 From: Brian Behlendorf Date: Fri, 17 Dec 2010 09:14:38 -0800 Subject: Add initial rw_uio functions to the dmu These functions were dropped originally because I felt they would need to be rewritten anyway to avoid using uios. However, this patch readds then with they dea they can just be reworked and the uio bits dropped. --- include/sys/dmu.h | 10 ++++- module/zfs/dmu.c | 112 ++++++++++++++++++++++++++++++++++++++++++++++++++++-- 2 files changed, 117 insertions(+), 5 deletions(-) diff --git a/include/sys/dmu.h b/include/sys/dmu.h index 575cb2d10..a8edfdbf8 100644 --- a/include/sys/dmu.h +++ b/include/sys/dmu.h @@ -515,12 +515,18 @@ void dmu_prealloc(objset_t *os, uint64_t object, uint64_t offset, uint64_t size, dmu_tx_t *tx); #ifdef _KERNEL int dmu_read_req(objset_t *os, uint64_t object, struct request *req); -int dmu_write_req(objset_t *os, uint64_t object, struct request *req, dmu_tx_t *tx); -#endif +int dmu_write_req(objset_t *os, uint64_t object, struct request *req, + dmu_tx_t *tx); +int dmu_read_uio(objset_t *os, uint64_t object, struct uio *uio, uint64_t size); +int dmu_write_uio(objset_t *os, uint64_t object, struct uio *uio, uint64_t size, + dmu_tx_t *tx); +int dmu_write_uio_dbuf(dmu_buf_t *zdb, struct uio *uio, uint64_t size, + dmu_tx_t *tx); #ifdef HAVE_ZPL int dmu_write_pages(objset_t *os, uint64_t object, uint64_t offset, uint64_t size, struct page *pp, dmu_tx_t *tx); #endif +#endif struct arc_buf *dmu_request_arcbuf(dmu_buf_t *handle, int size); void dmu_return_arcbuf(struct arc_buf *buf); void dmu_assign_arcbuf(dmu_buf_t *handle, uint64_t offset, struct arc_buf *buf, diff --git a/module/zfs/dmu.c b/module/zfs/dmu.c index aaeec418d..79024e1ee 100644 --- a/module/zfs/dmu.c +++ b/module/zfs/dmu.c @@ -1122,9 +1122,113 @@ dmu_write_req(objset_t *os, uint64_t object, struct request *req, dmu_tx_t *tx) dmu_buf_rele_array(dbp, numbufs, FTAG); return (err); } -#endif -#ifdef HAVE_ZPL +int +dmu_read_uio(objset_t *os, uint64_t object, uio_t *uio, uint64_t size) +{ + dmu_buf_t **dbp; + int numbufs, i, err; + xuio_t *xuio = NULL; + + /* + * NB: we could do this block-at-a-time, but it's nice + * to be reading in parallel. + */ + err = dmu_buf_hold_array(os, object, uio->uio_loffset, size, TRUE, FTAG, + &numbufs, &dbp); + if (err) + return (err); + + for (i = 0; i < numbufs; i++) { + int tocpy; + int bufoff; + dmu_buf_t *db = dbp[i]; + + ASSERT(size > 0); + + bufoff = uio->uio_loffset - db->db_offset; + tocpy = (int)MIN(db->db_size - bufoff, size); + + if (xuio) { + dmu_buf_impl_t *dbi = (dmu_buf_impl_t *)db; + arc_buf_t *dbuf_abuf = dbi->db_buf; + arc_buf_t *abuf = dbuf_loan_arcbuf(dbi); + err = dmu_xuio_add(xuio, abuf, bufoff, tocpy); + if (!err) { + uio->uio_resid -= tocpy; + uio->uio_loffset += tocpy; + } + + if (abuf == dbuf_abuf) + XUIOSTAT_BUMP(xuiostat_rbuf_nocopy); + else + XUIOSTAT_BUMP(xuiostat_rbuf_copied); + } else { + err = uiomove((char *)db->db_data + bufoff, tocpy, + UIO_READ, uio); + } + if (err) + break; + + size -= tocpy; + } + dmu_buf_rele_array(dbp, numbufs, FTAG); + + return (err); +} + +static int +dmu_write_uio_dnode(dnode_t *dn, uio_t *uio, uint64_t size, dmu_tx_t *tx) +{ + dmu_buf_t **dbp; + int numbufs; + int err = 0; + int i; + + err = dmu_buf_hold_array_by_dnode(dn, uio->uio_loffset, size, + FALSE, FTAG, &numbufs, &dbp, DMU_READ_PREFETCH); + if (err) + return (err); + + for (i = 0; i < numbufs; i++) { + int tocpy; + int bufoff; + dmu_buf_t *db = dbp[i]; + + ASSERT(size > 0); + + bufoff = uio->uio_loffset - db->db_offset; + tocpy = (int)MIN(db->db_size - bufoff, size); + + ASSERT(i == 0 || i == numbufs-1 || tocpy == db->db_size); + + if (tocpy == db->db_size) + dmu_buf_will_fill(db, tx); + else + dmu_buf_will_dirty(db, tx); + + /* + * XXX uiomove could block forever (eg.nfs-backed + * pages). There needs to be a uiolockdown() function + * to lock the pages in memory, so that uiomove won't + * block. + */ + err = uiomove((char *)db->db_data + bufoff, tocpy, + UIO_WRITE, uio); + + if (tocpy == db->db_size) + dmu_buf_fill_done(db, tx); + + if (err) + break; + + size -= tocpy; + } + + dmu_buf_rele_array(dbp, numbufs, FTAG); + return (err); +} + int dmu_write_uio_dbuf(dmu_buf_t *zdb, uio_t *uio, uint64_t size, dmu_tx_t *tx) @@ -1165,6 +1269,7 @@ dmu_write_uio(objset_t *os, uint64_t object, uio_t *uio, uint64_t size, return (err); } +#ifdef HAVE_ZPL int dmu_write_pages(objset_t *os, uint64_t object, uint64_t offset, uint64_t size, page_t *pp, dmu_tx_t *tx) @@ -1219,7 +1324,8 @@ dmu_write_pages(objset_t *os, uint64_t object, uint64_t offset, uint64_t size, dmu_buf_rele_array(dbp, numbufs, FTAG); return (err); } -#endif +#endif /* HAVE_ZPL */ +#endif /* _KERNEL */ /* * Allocate a loaned anonymous arc buffer. -- cgit v1.2.3