--- /dev/null
+/*
+ * Copyright (c) 2000-2003 Silicon Graphics, Inc. All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it would be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * Further, this software is distributed without any warranty that it is
+ * free of the rightful claim of any third person regarding infringement
+ * or the like. Any license provided herein, whether implied or
+ * otherwise, applies only to this software file. Patent licenses, if
+ * any, provided herein do not apply to combinations of this program with
+ * other software, or any other product whatsoever.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write the Free Software Foundation, Inc., 59
+ * Temple Place - Suite 330, Boston MA 02111-1307, USA.
+ *
+ * Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy,
+ * Mountain View, CA 94043, or:
+ *
+ * http://www.sgi.com
+ *
+ * For further information regarding this notice, see:
+ *
+ * http://oss.sgi.com/projects/GenInfo/SGIGPLNoticeExplan/
+ */
+/*
+ * fs/xfs/linux/xfs_lrw.c (Linux Read Write stuff)
+ *
+ */
+
+#include "xfs.h"
+
+#include "xfs_fs.h"
+#include "xfs_inum.h"
+#include "xfs_log.h"
+#include "xfs_trans.h"
+#include "xfs_sb.h"
+#include "xfs_ag.h"
+#include "xfs_dir.h"
+#include "xfs_dir2.h"
+#include "xfs_alloc.h"
+#include "xfs_dmapi.h"
+#include "xfs_quota.h"
+#include "xfs_mount.h"
+#include "xfs_alloc_btree.h"
+#include "xfs_bmap_btree.h"
+#include "xfs_ialloc_btree.h"
+#include "xfs_btree.h"
+#include "xfs_ialloc.h"
+#include "xfs_attr_sf.h"
+#include "xfs_dir_sf.h"
+#include "xfs_dir2_sf.h"
+#include "xfs_dinode.h"
+#include "xfs_inode.h"
+#include "xfs_bmap.h"
+#include "xfs_bit.h"
+#include "xfs_rtalloc.h"
+#include "xfs_error.h"
+#include "xfs_itable.h"
+#include "xfs_rw.h"
+#include "xfs_acl.h"
+#include "xfs_cap.h"
+#include "xfs_mac.h"
+#include "xfs_attr.h"
+#include "xfs_inode_item.h"
+#include "xfs_buf_item.h"
+#include "xfs_utils.h"
+#include "xfs_iomap.h"
+
+#include <linux/capability.h>
+
+
+#if defined(XFS_RW_TRACE)
+void
+xfs_rw_enter_trace(
+ int tag,
+ xfs_iocore_t *io,
+ const struct iovec *iovp,
+ size_t segs,
+ loff_t offset,
+ int ioflags)
+{
+ xfs_inode_t *ip = XFS_IO_INODE(io);
+
+ if (ip->i_rwtrace == NULL)
+ return;
+ ktrace_enter(ip->i_rwtrace,
+ (void *)(unsigned long)tag,
+ (void *)ip,
+ (void *)((unsigned long)((ip->i_d.di_size >> 32) & 0xffffffff)),
+ (void *)((unsigned long)(ip->i_d.di_size & 0xffffffff)),
+ (void *)(__psint_t)iovp,
+ (void *)((unsigned long)segs),
+ (void *)((unsigned long)((offset >> 32) & 0xffffffff)),
+ (void *)((unsigned long)(offset & 0xffffffff)),
+ (void *)((unsigned long)ioflags),
+ (void *)((unsigned long)((io->io_new_size >> 32) & 0xffffffff)),
+ (void *)((unsigned long)(io->io_new_size & 0xffffffff)),
+ (void *)NULL,
+ (void *)NULL,
+ (void *)NULL,
+ (void *)NULL,
+ (void *)NULL);
+}
+
+void
+xfs_inval_cached_trace(
+ xfs_iocore_t *io,
+ xfs_off_t offset,
+ xfs_off_t len,
+ xfs_off_t first,
+ xfs_off_t last)
+{
+ xfs_inode_t *ip = XFS_IO_INODE(io);
+
+ if (ip->i_rwtrace == NULL)
+ return;
+ ktrace_enter(ip->i_rwtrace,
+ (void *)(__psint_t)XFS_INVAL_CACHED,
+ (void *)ip,
+ (void *)((unsigned long)((offset >> 32) & 0xffffffff)),
+ (void *)((unsigned long)(offset & 0xffffffff)),
+ (void *)((unsigned long)((len >> 32) & 0xffffffff)),
+ (void *)((unsigned long)(len & 0xffffffff)),
+ (void *)((unsigned long)((first >> 32) & 0xffffffff)),
+ (void *)((unsigned long)(first & 0xffffffff)),
+ (void *)((unsigned long)((last >> 32) & 0xffffffff)),
+ (void *)((unsigned long)(last & 0xffffffff)),
+ (void *)NULL,
+ (void *)NULL,
+ (void *)NULL,
+ (void *)NULL,
+ (void *)NULL,
+ (void *)NULL);
+}
+#endif
+
+/*
+ * xfs_iozero
+ *
+ * xfs_iozero clears the specified range of buffer supplied,
+ * and marks all the affected blocks as valid and modified. If
+ * an affected block is not allocated, it will be allocated. If
+ * an affected block is not completely overwritten, and is not
+ * valid before the operation, it will be read from disk before
+ * being partially zeroed.
+ */
+STATIC int
+xfs_iozero(
+ struct inode *ip, /* inode */
+ loff_t pos, /* offset in file */
+ size_t count, /* size of data to zero */
+ loff_t end_size) /* max file size to set */
+{
+ unsigned bytes;
+ struct page *page;
+ struct address_space *mapping;
+ char *kaddr;
+ int status;
+
+ mapping = ip->i_mapping;
+ do {
+ unsigned long index, offset;
+
+ offset = (pos & (PAGE_CACHE_SIZE -1)); /* Within page */
+ index = pos >> PAGE_CACHE_SHIFT;
+ bytes = PAGE_CACHE_SIZE - offset;
+ if (bytes > count)
+ bytes = count;
+
+ status = -ENOMEM;
+ page = grab_cache_page(mapping, index);
+ if (!page)
+ break;
+
+ kaddr = kmap(page);
+ status = mapping->a_ops->prepare_write(NULL, page, offset,
+ offset + bytes);
+ if (status) {
+ goto unlock;
+ }
+
+ memset((void *) (kaddr + offset), 0, bytes);
+ flush_dcache_page(page);
+ status = mapping->a_ops->commit_write(NULL, page, offset,
+ offset + bytes);
+ if (!status) {
+ pos += bytes;
+ count -= bytes;
+ if (pos > i_size_read(ip))
+ i_size_write(ip, pos < end_size ? pos : end_size);
+ }
+
+unlock:
+ kunmap(page);
+ unlock_page(page);
+ page_cache_release(page);
+ if (status)
+ break;
+ } while (count);
+
+ return (-status);
+}
+
+/*
+ * xfs_inval_cached_pages
+ *
+ * This routine is responsible for keeping direct I/O and buffered I/O
+ * somewhat coherent. From here we make sure that we're at least
+ * temporarily holding the inode I/O lock exclusively and then call
+ * the page cache to flush and invalidate any cached pages. If there
+ * are no cached pages this routine will be very quick.
+ */
+void
+xfs_inval_cached_pages(
+ vnode_t *vp,
+ xfs_iocore_t *io,
+ xfs_off_t offset,
+ int write,
+ int relock)
+{
+ xfs_mount_t *mp;
+
+ if (!VN_CACHED(vp)) {
+ return;
+ }
+
+ mp = io->io_mount;
+
+ /*
+ * We need to get the I/O lock exclusively in order
+ * to safely invalidate pages and mappings.
+ */
+ if (relock) {
+ XFS_IUNLOCK(mp, io, XFS_IOLOCK_SHARED);
+ XFS_ILOCK(mp, io, XFS_IOLOCK_EXCL);
+ }
+
+ /* Writing beyond EOF creates a hole that must be zeroed */
+ if (write && (offset > XFS_SIZE(mp, io))) {
+ xfs_fsize_t isize;
+
+ XFS_ILOCK(mp, io, XFS_ILOCK_EXCL|XFS_EXTSIZE_RD);
+ isize = XFS_SIZE(mp, io);
+ if (offset > isize) {
+ xfs_zero_eof(vp, io, offset, isize, offset);
+ }
+ XFS_IUNLOCK(mp, io, XFS_ILOCK_EXCL|XFS_EXTSIZE_RD);
+ }
+
+ xfs_inval_cached_trace(io, offset, -1, ctooff(offtoct(offset)), -1);
+ VOP_FLUSHINVAL_PAGES(vp, ctooff(offtoct(offset)), -1, FI_REMAPF_LOCKED);
+ if (relock) {
+ XFS_ILOCK_DEMOTE(mp, io, XFS_IOLOCK_EXCL);
+ }
+}
+
+ssize_t /* bytes read, or (-) error */
+xfs_read(
+ bhv_desc_t *bdp,
+ struct kiocb *iocb,
+ const struct iovec *iovp,
+ unsigned int segs,
+ loff_t *offset,
+ int ioflags,
+ cred_t *credp)
+{
+ struct file *file = iocb->ki_filp;
+ size_t size = 0;
+ ssize_t ret;
+ xfs_fsize_t n;
+ xfs_inode_t *ip;
+ xfs_mount_t *mp;
+ vnode_t *vp;
+ unsigned long seg;
+
+ ip = XFS_BHVTOI(bdp);
+ vp = BHV_TO_VNODE(bdp);
+ mp = ip->i_mount;
+
+ XFS_STATS_INC(xs_read_calls);
+
+ /* START copy & waste from filemap.c */
+ for (seg = 0; seg < segs; seg++) {
+ const struct iovec *iv = &iovp[seg];
+
+ /*
+ * If any segment has a negative length, or the cumulative
+ * length ever wraps negative then return -EINVAL.
+ */
+ size += iv->iov_len;
+ if (unlikely((ssize_t)(size|iv->iov_len) < 0))
+ return XFS_ERROR(-EINVAL);
+ }
+ /* END copy & waste from filemap.c */
+
+ if (ioflags & IO_ISDIRECT) {
+ xfs_buftarg_t *target =
+ (ip->i_d.di_flags & XFS_DIFLAG_REALTIME) ?
+ mp->m_rtdev_targp : mp->m_ddev_targp;
+ if ((*offset & target->pbr_smask) ||
+ (size & target->pbr_smask)) {
+ if (*offset == ip->i_d.di_size) {
+ return (0);
+ }
+ return -XFS_ERROR(EINVAL);
+ }
+ }
+
+ n = XFS_MAXIOFFSET(mp) - *offset;
+ if ((n <= 0) || (size == 0))
+ return 0;
+
+ if (n < size)
+ size = n;
+
+ if (XFS_FORCED_SHUTDOWN(mp)) {
+ return -EIO;
+ }
+
+ /* OK so we are holding the I/O lock for the duration
+ * of the submission, then what happens if the I/O
+ * does not really happen here, but is scheduled
+ * later?
+ */
+ xfs_ilock(ip, XFS_IOLOCK_SHARED);
+
+ if (DM_EVENT_ENABLED(vp->v_vfsp, ip, DM_EVENT_READ) &&
+ !(ioflags & IO_INVIS)) {
+ vrwlock_t locktype = VRWLOCK_READ;
+
+ ret = XFS_SEND_DATA(mp, DM_EVENT_READ,
+ BHV_TO_VNODE(bdp), *offset, size,
+ FILP_DELAY_FLAG(file), &locktype);
+ if (ret) {
+ xfs_iunlock(ip, XFS_IOLOCK_SHARED);
+ return -ret;
+ }
+ }
+
+ xfs_rw_enter_trace(XFS_READ_ENTER, &ip->i_iocore,
+ iovp, segs, *offset, ioflags);
+ ret = __generic_file_aio_read(iocb, iovp, segs, offset);
+ xfs_iunlock(ip, XFS_IOLOCK_SHARED);
+
+ if (ret > 0)
+ XFS_STATS_ADD(xs_read_bytes, ret);
+
+ if (likely(!(ioflags & IO_INVIS)))
+ xfs_ichgtime(ip, XFS_ICHGTIME_ACC);
+
+ return ret;
+}
+
+ssize_t
+xfs_sendfile(
+ bhv_desc_t *bdp,
+ struct file *filp,
+ loff_t *offset,
+ int ioflags,
+ size_t count,
+ read_actor_t actor,
+ void *target,
+ cred_t *credp)
+{
+ ssize_t ret;
+ xfs_fsize_t n;
+ xfs_inode_t *ip;
+ xfs_mount_t *mp;
+ vnode_t *vp;
+
+ ip = XFS_BHVTOI(bdp);
+ vp = BHV_TO_VNODE(bdp);
+ mp = ip->i_mount;
+
+ XFS_STATS_INC(xs_read_calls);
+
+ n = XFS_MAXIOFFSET(mp) - *offset;
+ if ((n <= 0) || (count == 0))
+ return 0;
+
+ if (n < count)
+ count = n;
+
+ if (XFS_FORCED_SHUTDOWN(ip->i_mount))
+ return -EIO;
+
+ xfs_ilock(ip, XFS_IOLOCK_SHARED);
+
+ if (DM_EVENT_ENABLED(vp->v_vfsp, ip, DM_EVENT_READ) &&
+ (!(ioflags & IO_INVIS))) {
+ vrwlock_t locktype = VRWLOCK_READ;
+ int error;
+
+ error = XFS_SEND_DATA(mp, DM_EVENT_READ, BHV_TO_VNODE(bdp), *offset, count,
+ FILP_DELAY_FLAG(filp), &locktype);
+ if (error) {
+ xfs_iunlock(ip, XFS_IOLOCK_SHARED);
+ return -error;
+ }
+ }
+ xfs_rw_enter_trace(XFS_SENDFILE_ENTER, &ip->i_iocore,
+ target, count, *offset, ioflags);
+ ret = generic_file_sendfile(filp, offset, count, actor, target);
+ xfs_iunlock(ip, XFS_IOLOCK_SHARED);
+
+ XFS_STATS_ADD(xs_read_bytes, ret);
+ xfs_ichgtime(ip, XFS_ICHGTIME_ACC);
+ return ret;
+}
+
+/*
+ * This routine is called to handle zeroing any space in the last
+ * block of the file that is beyond the EOF. We do this since the
+ * size is being increased without writing anything to that block
+ * and we don't want anyone to read the garbage on the disk.
+ */
+STATIC int /* error (positive) */
+xfs_zero_last_block(
+ struct inode *ip,
+ xfs_iocore_t *io,
+ xfs_off_t offset,
+ xfs_fsize_t isize,
+ xfs_fsize_t end_size)
+{
+ xfs_fileoff_t last_fsb;
+ xfs_mount_t *mp;
+ int nimaps;
+ int zero_offset;
+ int zero_len;
+ int isize_fsb_offset;
+ int error = 0;
+ xfs_bmbt_irec_t imap;
+ loff_t loff;
+ size_t lsize;
+
+ ASSERT(ismrlocked(io->io_lock, MR_UPDATE) != 0);
+ ASSERT(offset > isize);
+
+ mp = io->io_mount;
+
+ isize_fsb_offset = XFS_B_FSB_OFFSET(mp, isize);
+ if (isize_fsb_offset == 0) {
+ /*
+ * There are no extra bytes in the last block on disk to
+ * zero, so return.
+ */
+ return 0;
+ }
+
+ last_fsb = XFS_B_TO_FSBT(mp, isize);
+ nimaps = 1;
+ error = XFS_BMAPI(mp, NULL, io, last_fsb, 1, 0, NULL, 0, &imap,
+ &nimaps, NULL);
+ if (error) {
+ return error;
+ }
+ ASSERT(nimaps > 0);
+ /*
+ * If the block underlying isize is just a hole, then there
+ * is nothing to zero.
+ */
+ if (imap.br_startblock == HOLESTARTBLOCK) {
+ return 0;
+ }
+ /*
+ * Zero the part of the last block beyond the EOF, and write it
+ * out sync. We need to drop the ilock while we do this so we
+ * don't deadlock when the buffer cache calls back to us.
+ */
+ XFS_IUNLOCK(mp, io, XFS_ILOCK_EXCL| XFS_EXTSIZE_RD);
+ loff = XFS_FSB_TO_B(mp, last_fsb);
+ lsize = XFS_FSB_TO_B(mp, 1);
+
+ zero_offset = isize_fsb_offset;
+ zero_len = mp->m_sb.sb_blocksize - isize_fsb_offset;
+
+ error = xfs_iozero(ip, loff + zero_offset, zero_len, end_size);
+
+ XFS_ILOCK(mp, io, XFS_ILOCK_EXCL|XFS_EXTSIZE_RD);
+ ASSERT(error >= 0);
+ return error;
+}
+
+/*
+ * Zero any on disk space between the current EOF and the new,
+ * larger EOF. This handles the normal case of zeroing the remainder
+ * of the last block in the file and the unusual case of zeroing blocks
+ * out beyond the size of the file. This second case only happens
+ * with fixed size extents and when the system crashes before the inode
+ * size was updated but after blocks were allocated. If fill is set,
+ * then any holes in the range are filled and zeroed. If not, the holes
+ * are left alone as holes.
+ */
+
+int /* error (positive) */
+xfs_zero_eof(
+ vnode_t *vp,
+ xfs_iocore_t *io,
+ xfs_off_t offset, /* starting I/O offset */
+ xfs_fsize_t isize, /* current inode size */
+ xfs_fsize_t end_size) /* terminal inode size */
+{
+ struct inode *ip = LINVFS_GET_IP(vp);
+ xfs_fileoff_t start_zero_fsb;
+ xfs_fileoff_t end_zero_fsb;
+ xfs_fileoff_t prev_zero_fsb;
+ xfs_fileoff_t zero_count_fsb;
+ xfs_fileoff_t last_fsb;
+ xfs_extlen_t buf_len_fsb;
+ xfs_extlen_t prev_zero_count;
+ xfs_mount_t *mp;
+ int nimaps;
+ int error = 0;
+ xfs_bmbt_irec_t imap;
+ loff_t loff;
+ size_t lsize;
+
+ ASSERT(ismrlocked(io->io_lock, MR_UPDATE));
+ ASSERT(ismrlocked(io->io_iolock, MR_UPDATE));
+
+ mp = io->io_mount;
+
+ /*
+ * First handle zeroing the block on which isize resides.
+ * We only zero a part of that block so it is handled specially.
+ */
+ error = xfs_zero_last_block(ip, io, offset, isize, end_size);
+ if (error) {
+ ASSERT(ismrlocked(io->io_lock, MR_UPDATE));
+ ASSERT(ismrlocked(io->io_iolock, MR_UPDATE));
+ return error;
+ }
+
+ /*
+ * Calculate the range between the new size and the old
+ * where blocks needing to be zeroed may exist. To get the
+ * block where the last byte in the file currently resides,
+ * we need to subtract one from the size and truncate back
+ * to a block boundary. We subtract 1 in case the size is
+ * exactly on a block boundary.
+ */
+ last_fsb = isize ? XFS_B_TO_FSBT(mp, isize - 1) : (xfs_fileoff_t)-1;
+ start_zero_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)isize);
+ end_zero_fsb = XFS_B_TO_FSBT(mp, offset - 1);
+ ASSERT((xfs_sfiloff_t)last_fsb < (xfs_sfiloff_t)start_zero_fsb);
+ if (last_fsb == end_zero_fsb) {
+ /*
+ * The size was only incremented on its last block.
+ * We took care of that above, so just return.
+ */
+ return 0;
+ }
+
+ ASSERT(start_zero_fsb <= end_zero_fsb);
+ prev_zero_fsb = NULLFILEOFF;
+ prev_zero_count = 0;
+ while (start_zero_fsb <= end_zero_fsb) {
+ nimaps = 1;
+ zero_count_fsb = end_zero_fsb - start_zero_fsb + 1;
+ error = XFS_BMAPI(mp, NULL, io, start_zero_fsb, zero_count_fsb,
+ 0, NULL, 0, &imap, &nimaps, NULL);
+ if (error) {
+ ASSERT(ismrlocked(io->io_lock, MR_UPDATE));
+ ASSERT(ismrlocked(io->io_iolock, MR_UPDATE));
+ return error;
+ }
+ ASSERT(nimaps > 0);
+
+ if (imap.br_state == XFS_EXT_UNWRITTEN ||
+ imap.br_startblock == HOLESTARTBLOCK) {
+ /*
+ * This loop handles initializing pages that were
+ * partially initialized by the code below this
+ * loop. It basically zeroes the part of the page
+ * that sits on a hole and sets the page as P_HOLE
+ * and calls remapf if it is a mapped file.
+ */
+ prev_zero_fsb = NULLFILEOFF;
+ prev_zero_count = 0;
+ start_zero_fsb = imap.br_startoff +
+ imap.br_blockcount;
+ ASSERT(start_zero_fsb <= (end_zero_fsb + 1));
+ continue;
+ }
+
+ /*
+ * There are blocks in the range requested.
+ * Zero them a single write at a time. We actually
+ * don't zero the entire range returned if it is
+ * too big and simply loop around to get the rest.
+ * That is not the most efficient thing to do, but it
+ * is simple and this path should not be exercised often.
+ */
+ buf_len_fsb = XFS_FILBLKS_MIN(imap.br_blockcount,
+ mp->m_writeio_blocks << 8);
+ /*
+ * Drop the inode lock while we're doing the I/O.
+ * We'll still have the iolock to protect us.
+ */
+ XFS_IUNLOCK(mp, io, XFS_ILOCK_EXCL|XFS_EXTSIZE_RD);
+
+ loff = XFS_FSB_TO_B(mp, start_zero_fsb);
+ lsize = XFS_FSB_TO_B(mp, buf_len_fsb);
+
+ error = xfs_iozero(ip, loff, lsize, end_size);
+
+ if (error) {
+ goto out_lock;
+ }
+
+ prev_zero_fsb = start_zero_fsb;
+ prev_zero_count = buf_len_fsb;
+ start_zero_fsb = imap.br_startoff + buf_len_fsb;
+ ASSERT(start_zero_fsb <= (end_zero_fsb + 1));
+
+ XFS_ILOCK(mp, io, XFS_ILOCK_EXCL|XFS_EXTSIZE_RD);
+ }
+
+ return 0;
+
+out_lock:
+
+ XFS_ILOCK(mp, io, XFS_ILOCK_EXCL|XFS_EXTSIZE_RD);
+ ASSERT(error >= 0);
+ return error;
+}
+
+ssize_t /* bytes written, or (-) error */
+xfs_write(
+ bhv_desc_t *bdp,
+ struct kiocb *iocb,
+ const struct iovec *iovp,
+ unsigned int segs,
+ loff_t *offset,
+ int ioflags,
+ cred_t *credp)
+{
+ struct file *file = iocb->ki_filp;
+ size_t size = 0;
+ xfs_inode_t *xip;
+ xfs_mount_t *mp;
+ ssize_t ret;
+ int error = 0;
+ xfs_fsize_t isize, new_size;
+ xfs_fsize_t n, limit;
+ xfs_iocore_t *io;
+ vnode_t *vp;
+ unsigned long seg;
+ int iolock;
+ int eventsent = 0;
+ vrwlock_t locktype;
+
+ XFS_STATS_INC(xs_write_calls);
+
+ vp = BHV_TO_VNODE(bdp);
+ xip = XFS_BHVTOI(bdp);
+
+ /* START copy & waste from filemap.c */
+ for (seg = 0; seg < segs; seg++) {
+ const struct iovec *iv = &iovp[seg];
+
+ /*
+ * If any segment has a negative length, or the cumulative
+ * length ever wraps negative then return -EINVAL.
+ */
+ size += iv->iov_len;
+ if (unlikely((ssize_t)(size|iv->iov_len) < 0))
+ return XFS_ERROR(-EINVAL);
+ }
+ /* END copy & waste from filemap.c */
+
+ if (size == 0)
+ return 0;
+
+ io = &xip->i_iocore;
+ mp = io->io_mount;
+
+ if (XFS_FORCED_SHUTDOWN(mp)) {
+ return -EIO;
+ }
+
+ if (ioflags & IO_ISDIRECT) {
+ xfs_buftarg_t *target =
+ (xip->i_d.di_flags & XFS_DIFLAG_REALTIME) ?
+ mp->m_rtdev_targp : mp->m_ddev_targp;
+
+ if ((*offset & target->pbr_smask) ||
+ (size & target->pbr_smask)) {
+ return XFS_ERROR(-EINVAL);
+ }
+ iolock = XFS_IOLOCK_SHARED;
+ locktype = VRWLOCK_WRITE_DIRECT;
+ } else {
+ iolock = XFS_IOLOCK_EXCL;
+ locktype = VRWLOCK_WRITE;
+ }
+
+ xfs_ilock(xip, XFS_ILOCK_EXCL|iolock);
+
+ isize = xip->i_d.di_size;
+ limit = XFS_MAXIOFFSET(mp);
+
+ if (file->f_flags & O_APPEND)
+ *offset = isize;
+
+start:
+ n = limit - *offset;
+ if (n <= 0) {
+ xfs_iunlock(xip, XFS_ILOCK_EXCL|iolock);
+ return -EFBIG;
+ }
+
+ if (n < size)
+ size = n;
+
+ new_size = *offset + size;
+ if (new_size > isize) {
+ io->io_new_size = new_size;
+ }
+
+ if ((DM_EVENT_ENABLED(vp->v_vfsp, xip, DM_EVENT_WRITE) &&
+ !(ioflags & IO_INVIS) && !eventsent)) {
+ loff_t savedsize = *offset;
+ int dmflags = FILP_DELAY_FLAG(file) | DM_SEM_FLAG_RD(ioflags);
+
+ xfs_iunlock(xip, XFS_ILOCK_EXCL);
+ error = XFS_SEND_DATA(xip->i_mount, DM_EVENT_WRITE, vp,
+ *offset, size,
+ dmflags, &locktype);
+ if (error) {
+ xfs_iunlock(xip, iolock);
+ return -error;
+ }
+ xfs_ilock(xip, XFS_ILOCK_EXCL);
+ eventsent = 1;
+
+ /*
+ * The iolock was dropped and reaquired in XFS_SEND_DATA
+ * so we have to recheck the size when appending.
+ * We will only "goto start;" once, since having sent the
+ * event prevents another call to XFS_SEND_DATA, which is
+ * what allows the size to change in the first place.
+ */
+ if ((file->f_flags & O_APPEND) &&
+ savedsize != xip->i_d.di_size) {
+ *offset = isize = xip->i_d.di_size;
+ goto start;
+ }
+ }
+
+ /*
+ * On Linux, generic_file_write updates the times even if
+ * no data is copied in so long as the write had a size.
+ *
+ * We must update xfs' times since revalidate will overcopy xfs.
+ */
+ if (size && !(ioflags & IO_INVIS))
+ xfs_ichgtime(xip, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
+
+ /*
+ * If the offset is beyond the size of the file, we have a couple
+ * of things to do. First, if there is already space allocated
+ * we need to either create holes or zero the disk or ...
+ *
+ * If there is a page where the previous size lands, we need
+ * to zero it out up to the new size.
+ */
+
+ if (!(ioflags & IO_ISDIRECT) && (*offset > isize && isize)) {
+ error = xfs_zero_eof(BHV_TO_VNODE(bdp), io, *offset,
+ isize, *offset + size);
+ if (error) {
+ xfs_iunlock(xip, XFS_ILOCK_EXCL|iolock);
+ return(-error);
+ }
+ }
+ xfs_iunlock(xip, XFS_ILOCK_EXCL);
+
+ /*
+ * If we're writing the file then make sure to clear the
+ * setuid and setgid bits if the process is not being run
+ * by root. This keeps people from modifying setuid and
+ * setgid binaries.
+ */
+
+ if (((xip->i_d.di_mode & S_ISUID) ||
+ ((xip->i_d.di_mode & (S_ISGID | S_IXGRP)) ==
+ (S_ISGID | S_IXGRP))) &&
+ !capable(CAP_FSETID)) {
+ error = xfs_write_clear_setuid(xip);
+ if (error) {
+ xfs_iunlock(xip, iolock);
+ return -error;
+ }
+ }
+
+retry:
+ if (ioflags & IO_ISDIRECT) {
+ xfs_inval_cached_pages(vp, io, *offset, 1, 1);
+ xfs_rw_enter_trace(XFS_DIOWR_ENTER,
+ io, iovp, segs, *offset, ioflags);
+ } else {
+ xfs_rw_enter_trace(XFS_WRITE_ENTER,
+ io, iovp, segs, *offset, ioflags);
+ }
+ ret = generic_file_aio_write_nolock(iocb, iovp, segs, offset);
+
+ if ((ret == -ENOSPC) &&
+ DM_EVENT_ENABLED(vp->v_vfsp, xip, DM_EVENT_NOSPACE) &&
+ !(ioflags & IO_INVIS)) {
+
+ xfs_rwunlock(bdp, locktype);
+ error = XFS_SEND_NAMESP(xip->i_mount, DM_EVENT_NOSPACE, vp,
+ DM_RIGHT_NULL, vp, DM_RIGHT_NULL, NULL, NULL,
+ 0, 0, 0); /* Delay flag intentionally unused */
+ if (error)
+ return -error;
+ xfs_rwlock(bdp, locktype);
+ *offset = xip->i_d.di_size;
+ goto retry;
+ }
+
+ if (*offset > xip->i_d.di_size) {
+ xfs_ilock(xip, XFS_ILOCK_EXCL);
+ if (*offset > xip->i_d.di_size) {
+ struct inode *inode = LINVFS_GET_IP(vp);
+
+ xip->i_d.di_size = *offset;
+ i_size_write(inode, *offset);
+ xip->i_update_core = 1;
+ xip->i_update_size = 1;
+ }
+ xfs_iunlock(xip, XFS_ILOCK_EXCL);
+ }
+
+ if (ret <= 0) {
+ xfs_rwunlock(bdp, locktype);
+ return ret;
+ }
+
+ XFS_STATS_ADD(xs_write_bytes, ret);
+
+ /* Handle various SYNC-type writes */
+ if ((file->f_flags & O_SYNC) || IS_SYNC(file->f_dentry->d_inode)) {
+
+ /*
+ * If we're treating this as O_DSYNC and we have not updated the
+ * size, force the log.
+ */
+
+ if (!(mp->m_flags & XFS_MOUNT_OSYNCISOSYNC)
+ && !(xip->i_update_size)) {
+ /*
+ * If an allocation transaction occurred
+ * without extending the size, then we have to force
+ * the log up the proper point to ensure that the
+ * allocation is permanent. We can't count on
+ * the fact that buffered writes lock out direct I/O
+ * writes - the direct I/O write could have extended
+ * the size nontransactionally, then finished before
+ * we started. xfs_write_file will think that the file
+ * didn't grow but the update isn't safe unless the
+ * size change is logged.
+ *
+ * Force the log if we've committed a transaction
+ * against the inode or if someone else has and
+ * the commit record hasn't gone to disk (e.g.
+ * the inode is pinned). This guarantees that
+ * all changes affecting the inode are permanent
+ * when we return.
+ */
+
+ xfs_inode_log_item_t *iip;
+ xfs_lsn_t lsn;
+
+ iip = xip->i_itemp;
+ if (iip && iip->ili_last_lsn) {
+ lsn = iip->ili_last_lsn;
+ xfs_log_force(mp, lsn,
+ XFS_LOG_FORCE | XFS_LOG_SYNC);
+ } else if (xfs_ipincount(xip) > 0) {
+ xfs_log_force(mp, (xfs_lsn_t)0,
+ XFS_LOG_FORCE | XFS_LOG_SYNC);
+ }
+
+ } else {
+ xfs_trans_t *tp;
+
+ /*
+ * O_SYNC or O_DSYNC _with_ a size update are handled
+ * the same way.
+ *
+ * If the write was synchronous then we need to make
+ * sure that the inode modification time is permanent.
+ * We'll have updated the timestamp above, so here
+ * we use a synchronous transaction to log the inode.
+ * It's not fast, but it's necessary.
+ *
+ * If this a dsync write and the size got changed
+ * non-transactionally, then we need to ensure that
+ * the size change gets logged in a synchronous
+ * transaction.
+ */
+
+ tp = xfs_trans_alloc(mp, XFS_TRANS_WRITE_SYNC);
+ if ((error = xfs_trans_reserve(tp, 0,
+ XFS_SWRITE_LOG_RES(mp),
+ 0, 0, 0))) {
+ /* Transaction reserve failed */
+ xfs_trans_cancel(tp, 0);
+ } else {
+ /* Transaction reserve successful */
+ xfs_ilock(xip, XFS_ILOCK_EXCL);
+ xfs_trans_ijoin(tp, xip, XFS_ILOCK_EXCL);
+ xfs_trans_ihold(tp, xip);
+ xfs_trans_log_inode(tp, xip, XFS_ILOG_CORE);
+ xfs_trans_set_sync(tp);
+ error = xfs_trans_commit(tp, 0, NULL);
+ xfs_iunlock(xip, XFS_ILOCK_EXCL);
+ }
+ }
+ } /* (ioflags & O_SYNC) */
+
+ xfs_rwunlock(bdp, locktype);
+ return(ret);
+}
+
+/*
+ * All xfs metadata buffers except log state machine buffers
+ * get this attached as their b_bdstrat callback function.
+ * This is so that we can catch a buffer
+ * after prematurely unpinning it to forcibly shutdown the filesystem.
+ */
+int
+xfs_bdstrat_cb(struct xfs_buf *bp)
+{
+ xfs_mount_t *mp;
+
+ mp = XFS_BUF_FSPRIVATE3(bp, xfs_mount_t *);
+ if (!XFS_FORCED_SHUTDOWN(mp)) {
+ pagebuf_iorequest(bp);
+ return 0;
+ } else {
+ xfs_buftrace("XFS__BDSTRAT IOERROR", bp);
+ /*
+ * Metadata write that didn't get logged but
+ * written delayed anyway. These aren't associated
+ * with a transaction, and can be ignored.
+ */
+ if (XFS_BUF_IODONE_FUNC(bp) == NULL &&
+ (XFS_BUF_ISREAD(bp)) == 0)
+ return (xfs_bioerror_relse(bp));
+ else
+ return (xfs_bioerror(bp));
+ }
+}
+
+
+int
+xfs_bmap(bhv_desc_t *bdp,
+ xfs_off_t offset,
+ ssize_t count,
+ int flags,
+ xfs_iomap_t *iomapp,
+ int *niomaps)
+{
+ xfs_inode_t *ip = XFS_BHVTOI(bdp);
+ xfs_iocore_t *io = &ip->i_iocore;
+
+ ASSERT((ip->i_d.di_mode & S_IFMT) == S_IFREG);
+ ASSERT(((ip->i_d.di_flags & XFS_DIFLAG_REALTIME) != 0) ==
+ ((ip->i_iocore.io_flags & XFS_IOCORE_RT) != 0));
+
+ return xfs_iomap(io, offset, count, flags, iomapp, niomaps);
+}
+
+/*
+ * Wrapper around bdstrat so that we can stop data
+ * from going to disk in case we are shutting down the filesystem.
+ * Typically user data goes thru this path; one of the exceptions
+ * is the superblock.
+ */
+int
+xfsbdstrat(
+ struct xfs_mount *mp,
+ struct xfs_buf *bp)
+{
+ ASSERT(mp);
+ if (!XFS_FORCED_SHUTDOWN(mp)) {
+ /* Grio redirection would go here
+ * if (XFS_BUF_IS_GRIO(bp)) {
+ */
+
+ pagebuf_iorequest(bp);
+ return 0;
+ }
+
+ xfs_buftrace("XFSBDSTRAT IOERROR", bp);
+ return (xfs_bioerror_relse(bp));
+}
+
+/*
+ * If the underlying (data/log/rt) device is readonly, there are some
+ * operations that cannot proceed.
+ */
+int
+xfs_dev_is_read_only(
+ xfs_mount_t *mp,
+ char *message)
+{
+ if (xfs_readonly_buftarg(mp->m_ddev_targp) ||
+ xfs_readonly_buftarg(mp->m_logdev_targp) ||
+ (mp->m_rtdev_targp && xfs_readonly_buftarg(mp->m_rtdev_targp))) {
+ cmn_err(CE_NOTE,
+ "XFS: %s required on read-only device.", message);
+ cmn_err(CE_NOTE,
+ "XFS: write access unavailable, cannot proceed.");
+ return EROFS;
+ }
+ return 0;
+}
git://git.onelab.eu / linux-2.6.git / blobdiff