File: [Development] / xfs-linux / linux-2.4 / Attic / xfs_lrw.c (download)
Revision 1.237, Thu Jun 15 03:55:18 2006 UTC (11 years, 4 months ago) by nathans.longdrop.melbourne.sgi.com
Branch: MAIN
Changes since 1.236: +5 -79
lines
Push some common code out of write path into core XFS code for sharing.
Merge of xfs-linux-melb:xfs-kern:26248a by kenmcd.
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/*
* Copyright (c) 2000-2003,2005 Silicon Graphics, Inc.
* All Rights Reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms 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. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "xfs.h"
#include "xfs_fs.h"
#include "xfs_bit.h"
#include "xfs_log.h"
#include "xfs_inum.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_bmap_btree.h"
#include "xfs_alloc_btree.h"
#include "xfs_ialloc_btree.h"
#include "xfs_dir_sf.h"
#include "xfs_dir2_sf.h"
#include "xfs_attr_sf.h"
#include "xfs_dinode.h"
#include "xfs_inode.h"
#include "xfs_bmap.h"
#include "xfs_btree.h"
#include "xfs_ialloc.h"
#include "xfs_rtalloc.h"
#include "xfs_error.h"
#include "xfs_itable.h"
#include "xfs_rw.h"
#include "xfs_refcache.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 LINUX_VERSION_CODE >= KERNEL_VERSION(2,4,22)
#define do_down_read(x) down_read(x)
#define do_up_read(x) up_read(x)
#else
#define do_down_read(x)
#define do_up_read(x)
#endif
static inline void dm_sem_up(
struct inode *inode,
int ioflags)
{
if (ioflags & IO_ISDIRECT) {
do_up_read(&inode->i_alloc_sem);
}
else {
up(&inode->i_sem);
}
}
static inline void dm_sem_down(
struct inode *inode,
int ioflags)
{
if (ioflags & IO_ISDIRECT) {
do_down_read(&inode->i_alloc_sem);
}
else {
down(&inode->i_sem);
}
}
#if defined(XFS_RW_TRACE)
void
xfs_rw_enter_trace(
int tag,
xfs_iocore_t *io,
const char *buf,
size_t size,
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)buf,
(void *)((unsigned long)size),
(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 *)((unsigned long)current_pid()),
(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 *)((unsigned long)current_pid()),
(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.
*/
STATIC void
xfs_inval_cached_pages(
bhv_vnode_t *vp,
xfs_iocore_t *io,
xfs_off_t offset)
{
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.
*/
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 (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);
bhv_vop_flushinval_pages(vp, ctooff(offtoct(offset)), -1, FI_REMAPF_LOCKED);
XFS_ILOCK_DEMOTE(mp, io, XFS_IOLOCK_EXCL);
}
ssize_t /* bytes read, or (-) error */
xfs_read(
bhv_desc_t *bdp,
struct file *file,
char *buf,
size_t size,
loff_t *offset,
int ioflags,
cred_t *credp)
{
ssize_t ret;
xfs_fsize_t n;
xfs_inode_t *ip;
xfs_mount_t *mp;
ip = XFS_BHVTOI(bdp);
mp = ip->i_mount;
XFS_STATS_INC(xs_read_calls);
if (unlikely(ioflags & IO_ISDIRECT)) {
if ((ssize_t)size < 0)
return -XFS_ERROR(EINVAL);
if (((__psint_t)buf & BBMASK) ||
(*offset & mp->m_blockmask) ||
(size & mp->m_blockmask)) {
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;
}
if (!(ioflags & IO_ISLOCKED))
xfs_ilock(ip, XFS_IOLOCK_SHARED);
if (DM_EVENT_ENABLED(BHV_TO_VNODE(bdp)->v_vfsp, ip, DM_EVENT_READ) &&
!(ioflags & IO_INVIS)) {
int error;
bhv_vrwlock_t locktype = VRWLOCK_READ;
int dmflags = FILP_DELAY_FLAG(file) | DM_SEM_FLAG_RD(ioflags);
error = XFS_SEND_DATA(mp, DM_EVENT_READ, BHV_TO_VNODE(bdp), *offset, size,
dmflags, &locktype);
if (error) {
if (!(ioflags & IO_ISLOCKED))
xfs_iunlock(ip, XFS_IOLOCK_SHARED);
return -error;
}
}
if (unlikely(ioflags & IO_ISDIRECT)) {
xfs_rw_enter_trace(XFS_DIORD_ENTER, &ip->i_iocore,
buf, size, *offset, ioflags);
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,4,22)
ret = (*offset < ip->i_d.di_size) ?
do_generic_direct_read(file, buf, size, offset) : 0;
UPDATE_ATIME(file->f_dentry->d_inode);
#else
ret = generic_file_read(file, buf, size, offset);
#endif
} else {
xfs_rw_enter_trace(XFS_READ_ENTER, &ip->i_iocore,
buf, size, *offset, ioflags);
ret = generic_file_read(file, buf, size, offset);
}
if (ret > 0)
XFS_STATS_ADD(xs_read_bytes, ret);
if (!(ioflags & IO_ISLOCKED))
xfs_iunlock(ip, XFS_IOLOCK_SHARED);
if (unlikely(ioflags & IO_INVIS)) {
/* generic_file_read updates the atime but we need to
* undo that because this I/O was supposed to be invisible.
*/
struct inode *inode = vn_to_inode(BHV_TO_VNODE(bdp));
inode->i_atime = ip->i_d.di_atime.t_sec;
} else {
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_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 error = 0;
xfs_bmbt_irec_t imap;
loff_t loff;
ASSERT(ismrlocked(io->io_lock, MR_UPDATE) != 0);
mp = io->io_mount;
zero_offset = XFS_B_FSB_OFFSET(mp, isize);
if (zero_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, 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);
zero_len = mp->m_sb.sb_blocksize - zero_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(
bhv_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 = vn_to_inode(vp);
xfs_fileoff_t start_zero_fsb;
xfs_fileoff_t end_zero_fsb;
xfs_fileoff_t zero_count_fsb;
xfs_fileoff_t last_fsb;
xfs_mount_t *mp;
int nimaps;
int error = 0;
xfs_bmbt_irec_t imap;
ASSERT(ismrlocked(io->io_lock, MR_UPDATE));
ASSERT(ismrlocked(io->io_iolock, MR_UPDATE));
ASSERT(offset > isize);
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, 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);
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, 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.
*/
start_zero_fsb = imap.br_startoff + imap.br_blockcount;
ASSERT(start_zero_fsb <= (end_zero_fsb + 1));
continue;
}
/*
* There are blocks we need to zero.
* 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);
error = xfs_iozero(ip,
XFS_FSB_TO_B(mp, start_zero_fsb),
XFS_FSB_TO_B(mp, imap.br_blockcount),
end_size);
if (error) {
goto out_lock;
}
start_zero_fsb = imap.br_startoff + imap.br_blockcount;
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 file *file,
const char *buf,
size_t size,
loff_t *offset,
int ioflags,
cred_t *credp)
{
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;
struct inode *inode;
xfs_iocore_t *io;
bhv_vnode_t *vp;
int iolock;
int eventsent = 0;
bhv_vrwlock_t locktype;
XFS_STATS_INC(xs_write_calls);
vp = BHV_TO_VNODE(bdp);
xip = XFS_BHVTOI(bdp);
inode = vn_to_inode(vp);
if (size == 0)
return 0;
io = &xip->i_iocore;
mp = io->io_mount;
vfs_wait_for_freeze(vp->v_vfsp, SB_FREEZE_WRITE);
if (XFS_FORCED_SHUTDOWN(xip->i_mount))
return -EIO;
if (unlikely(ioflags & IO_ISDIRECT)) {
if (((__psint_t)buf & BBMASK) ||
(*offset & mp->m_blockmask) ||
(size & mp->m_blockmask)) {
return XFS_ERROR(-EINVAL);
}
iolock = XFS_IOLOCK_SHARED;
locktype = VRWLOCK_WRITE_DIRECT;
} else {
iolock = XFS_IOLOCK_EXCL;
locktype = VRWLOCK_WRITE;
}
if (ioflags & IO_ISLOCKED)
iolock = 0;
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) {
if (iolock)
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;
}
}
/*
* 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;
}
}
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,4,22)
if ((ssize_t) size < 0) {
ret = -EINVAL;
goto error;
}
if (!access_ok(VERIFY_READ, buf, size)) {
ret = -EINVAL;
goto error;
}
#else
#define do_generic_direct_write(file, buf, size, offset) \
generic_file_write_nolock(file, buf, size, offset)
#define do_generic_file_write(file, buf, size, offset) \
generic_file_write_nolock(file, buf, size, offset)
#endif
retry:
if (unlikely(ioflags & IO_ISDIRECT)) {
xfs_inval_cached_pages(vp, io, *offset);
xfs_rw_enter_trace(XFS_DIOWR_ENTER,
io, buf, size, *offset, ioflags);
ret = do_generic_direct_write(file, buf, size, offset);
} else {
xfs_rw_enter_trace(XFS_WRITE_ENTER,
io, buf, size, *offset, ioflags);
ret = do_generic_file_write(file, buf, size, offset);
}
if (unlikely(ioflags & IO_INVIS)) {
/* generic_file_write updates the mtime/ctime but we need
* to undo that because this I/O was supposed to be
* invisible.
*/
inode->i_mtime = xip->i_d.di_mtime.t_sec;
inode->i_ctime = xip->i_d.di_ctime.t_sec;
} else {
xfs_ichgtime(xip, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
}
if ((ret == -ENOSPC) &&
DM_EVENT_ENABLED(vp->v_vfsp, xip, DM_EVENT_NOSPACE) &&
!(ioflags & IO_INVIS)) {
dm_sem_up(inode, ioflags);
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 */
dm_sem_down(inode, ioflags);
if (error)
return -error;
xfs_rwlock(bdp, locktype);
*offset = xip->i_d.di_size;
goto retry;
}
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,4,22)
error:
#endif
if (ret <= 0) {
if (iolock)
xfs_rwunlock(bdp, locktype);
return ret;
}
XFS_STATS_ADD(xs_write_bytes, ret);
isize = i_size_read(inode);
if (unlikely(ret < 0 && ret != -EFAULT && *offset > isize))
*offset = isize;
if (*offset > xip->i_d.di_size) {
xfs_ilock(xip, XFS_ILOCK_EXCL);
if (*offset > xip->i_d.di_size) {
xip->i_d.di_size = *offset;
i_size_write(inode, *offset);
xip->i_update_core = 1;
xip->i_update_size = 1;
mark_inode_dirty_sync(inode);
}
xfs_iunlock(xip, XFS_ILOCK_EXCL);
}
/* Handle various SYNC-type writes */
if ((file->f_flags & O_SYNC) || IS_SYNC(file->f_dentry->d_inode)) {
error = xfs_write_sync_logforce(mp, xip);
if (error)
ret = -error;
}
/*
* If we are coming from an nfsd thread then insert into the
* reference cache.
*/
if (!strcmp(current->comm, "nfsd"))
xfs_refcache_insert(xip);
/* Drop lock this way - the old refcache release is in here */
if (iolock)
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)) {
xfs_buf_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)) {
xfs_buf_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;
}
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