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; 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); ret = (*offset < ip->i_d.di_size) ? do_generic_direct_read(file, buf, size, offset) : 0; UPDATE_ATIME(file->f_dentry->d_inode); } 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 = LINVFS_GET_IP(BHV_TO_VNODE(bdp)); inode->i_atime = ip->i_d.di_atime.t_sec; } else { xfs_ichgtime(ip, XFS_ICHGTIME_ACC); } return ret; }
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; xfs_iocore_t *io; vnode_t *vp; int iolock; int eventsent = 0; vrwlock_t locktype; XFS_STATS_INC(xs_write_calls); vp = BHV_TO_VNODE(bdp); xip = XFS_BHVTOI(bdp); if (size == 0) return 0; io = &xip->i_iocore; mp = io->io_mount; fs_check_frozen(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 ((ssize_t) size < 0) { ret = -EINVAL; goto error; } if (!access_ok(VERIFY_READ, buf, size)) { ret = -EINVAL; goto error; } retry: if (unlikely(ioflags & IO_ISDIRECT)) { xfs_inval_cached_pages(vp, io, *offset, 1, 1); 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. */ struct inode *inode = LINVFS_GET_IP(vp); 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)) { 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; } error: if (ret <= 0) { if (iolock) xfs_rwunlock(bdp, locktype); return ret; } XFS_STATS_ADD(xs_write_bytes, ret); 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; 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)) { /* * 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) */ /* * 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); }
STATIC ssize_t xfs_file_aio_read( struct kiocb *iocb, const struct iovec *iovp, unsigned long nr_segs, loff_t pos) { struct file *file = iocb->ki_filp; struct inode *inode = file->f_mapping->host; struct xfs_inode *ip = XFS_I(inode); struct xfs_mount *mp = ip->i_mount; size_t size = 0; ssize_t ret = 0; int ioflags = 0; xfs_fsize_t n; unsigned long seg; XFS_STATS_INC(xs_read_calls); BUG_ON(iocb->ki_pos != pos); if (unlikely(file->f_flags & O_DIRECT)) ioflags |= IO_ISDIRECT; if (file->f_mode & FMODE_NOCMTIME) ioflags |= IO_INVIS; /* START copy & waste from filemap.c */ for (seg = 0; seg < nr_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 (unlikely(ioflags & IO_ISDIRECT)) { xfs_buftarg_t *target = XFS_IS_REALTIME_INODE(ip) ? mp->m_rtdev_targp : mp->m_ddev_targp; if ((iocb->ki_pos & target->bt_smask) || (size & target->bt_smask)) { if (iocb->ki_pos == ip->i_size) return 0; return -XFS_ERROR(EINVAL); } } n = XFS_MAXIOFFSET(mp) - iocb->ki_pos; if (n <= 0 || size == 0) return 0; if (n < size) size = n; if (XFS_FORCED_SHUTDOWN(mp)) return -EIO; if (unlikely(ioflags & IO_ISDIRECT)) mutex_lock(&inode->i_mutex); xfs_ilock(ip, XFS_IOLOCK_SHARED); if (DM_EVENT_ENABLED(ip, DM_EVENT_READ) && !(ioflags & IO_INVIS)) { int dmflags = FILP_DELAY_FLAG(file) | DM_SEM_FLAG_RD(ioflags); int iolock = XFS_IOLOCK_SHARED; ret = -XFS_SEND_DATA(mp, DM_EVENT_READ, ip, iocb->ki_pos, size, dmflags, &iolock); if (ret) { xfs_iunlock(ip, XFS_IOLOCK_SHARED); if (unlikely(ioflags & IO_ISDIRECT)) mutex_unlock(&inode->i_mutex); return ret; } } if (unlikely(ioflags & IO_ISDIRECT)) { if (inode->i_mapping->nrpages) { ret = -xfs_flushinval_pages(ip, (iocb->ki_pos & PAGE_CACHE_MASK), -1, FI_REMAPF_LOCKED); } mutex_unlock(&inode->i_mutex); if (ret) { xfs_iunlock(ip, XFS_IOLOCK_SHARED); return ret; } } trace_xfs_file_read(ip, size, iocb->ki_pos, ioflags); ret = generic_file_aio_read(iocb, iovp, nr_segs, iocb->ki_pos); if (ret > 0) XFS_STATS_ADD(xs_read_bytes, ret); xfs_iunlock(ip, XFS_IOLOCK_SHARED); return ret; }
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; struct inode *inode = file->f_mapping->host; 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 (unlikely(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->bt_smask) || (size & target->bt_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; if (unlikely(ioflags & IO_ISDIRECT)) mutex_lock(&inode->i_mutex); 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 dmflags = FILP_DELAY_FLAG(file) | DM_SEM_FLAG_RD(ioflags); ret = -XFS_SEND_DATA(mp, DM_EVENT_READ, BHV_TO_VNODE(bdp), *offset, size, dmflags, &locktype); if (ret) { xfs_iunlock(ip, XFS_IOLOCK_SHARED); goto unlock_mutex; } } if (unlikely((ioflags & IO_ISDIRECT) && VN_CACHED(vp))) VOP_FLUSHINVAL_PAGES(vp, ctooff(offtoct(*offset)), -1, FI_REMAPF_LOCKED); xfs_rw_enter_trace(XFS_READ_ENTER, &ip->i_iocore, (void *)iovp, segs, *offset, ioflags); ret = __generic_file_aio_read(iocb, iovp, segs, offset); if (ret == -EIOCBQUEUED && !(ioflags & IO_ISAIO)) ret = wait_on_sync_kiocb(iocb); if (ret > 0) XFS_STATS_ADD(xs_read_bytes, ret); xfs_iunlock(ip, XFS_IOLOCK_SHARED); unlock_mutex: if (unlikely(ioflags & IO_ISDIRECT)) mutex_unlock(&inode->i_mutex); return ret; }
ssize_t /* bytes written, or (-) error */ xfs_write( bhv_desc_t *bdp, uio_t *uio, int ioflag, cred_t *credp) { xfs_inode_t *xip; xfs_mount_t *mp; ssize_t ret = 0; int error = 0; xfs_fsize_t isize, new_size; xfs_fsize_t n, limit; xfs_fsize_t size; xfs_iocore_t *io; xfs_vnode_t *vp; int iolock; //int eventsent = 0; vrwlock_t locktype; xfs_off_t offset_c; xfs_off_t *offset; xfs_off_t pos; XFS_STATS_INC(xs_write_calls); vp = BHV_TO_VNODE(bdp); xip = XFS_BHVTOI(bdp); io = &xip->i_iocore; mp = io->io_mount; if (XFS_FORCED_SHUTDOWN(xip->i_mount)) { return EIO; } size = uio->uio_resid; pos = offset_c = uio->uio_offset; offset = &offset_c; if (unlikely(ioflag & IO_ISDIRECT)) { if (((__psint_t)buf & BBMASK) || (*offset & mp->m_blockmask) || (size & mp->m_blockmask)) { return EINVAL; } iolock = XFS_IOLOCK_SHARED; locktype = VRWLOCK_WRITE_DIRECT; } else { if (io->io_flags & XFS_IOCORE_RT) return EINVAL; iolock = XFS_IOLOCK_EXCL; locktype = VRWLOCK_WRITE; } 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 (ioflag & 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; } #ifdef RMC /* probably be a long time before if ever that we do dmapi */ 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; } } #endif /* * 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 (!(ioflag & 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 0 /* * 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 (likely(!error)) error = -remove_suid(file->f_dentry); if (unlikely(error)) { xfs_iunlock(xip, iolock); goto out_unlock_mutex; } } #endif //retry: if (unlikely(ioflag & IO_ISDIRECT)) { #ifdef RMC xfs_off_t pos = *offset; struct address_space *mapping = file->f_dentry->d_inode->i_mapping; struct inode *inode = mapping->host; ret = precheck_file_write(file, inode, &size, &pos); if (ret || size == 0) goto error; xfs_inval_cached_pages(vp, io, pos, 1, 1); inode->i_ctime = inode->i_mtime = CURRENT_TIME; /* mark_inode_dirty_sync(inode); - we do this later */ xfs_rw_enter_trace(XFS_DIOWR_ENTER, io, buf, size, pos, ioflags); ret = generic_file_direct_IO(WRITE, file, (char *)buf, size, pos); xfs_inval_cached_pages(vp, io, pos, 1, 1); if (ret > 0) *offset += ret; #endif } else { xfs_rw_enter_trace(XFS_WRITE_ENTER, io, buf, size, *offset, ioflags); ret = xfs_write_file(xip,uio,ioflag); } xfs_ichgtime(xip, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG); //error: if (ret <= 0) { if (iolock) xfs_rwunlock(bdp, locktype); return ret; } XFS_STATS_ADD(xs_write_bytes, ret); if (*offset > xip->i_d.di_size) { xfs_ilock(xip, XFS_ILOCK_EXCL); if (*offset > xip->i_d.di_size) { printf("xfs_write look at doing more here %s:%d\n",__FILE__,__LINE__); #ifdef RMC struct inode *inode = LINVFS_GET_IP(vp); i_size_write(inode, *offset); mark_inode_dirty_sync(inode); #endif xip->i_d.di_size = *offset; xip->i_update_core = 1; xip->i_update_size = 1; } xfs_iunlock(xip, XFS_ILOCK_EXCL); } /* Handle various SYNC-type writes */ #if 0 // if ((file->f_flags & O_SYNC) || IS_SYNC(inode)) { #endif if (ioflag & IO_SYNC) { /* * 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)) { xfs_inode_log_item_t *iip = xip->i_itemp; /* * 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. */ if (iip && iip->ili_last_lsn) { xfs_log_force(mp, iip->ili_last_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); } if (error) goto out_unlock_internal; } xfs_rwunlock(bdp, locktype); return ret; } /* (ioflags & O_SYNC) */ out_unlock_internal: xfs_rwunlock(bdp, locktype); #if 0 out_unlock_mutex: if (need_i_mutex) mutex_unlock(&inode->i_mutex); #endif //out_nounlocks: return -error; }
ssize_t /* bytes read, or (-) error */ xfs_read( bhv_desc_t *bdp, uio_t *uio, int ioflags, cred_t *credp) { ssize_t ret, size; 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 (((__psint_t)buf & BBMASK) || (uio->uio_offset & mp->m_blockmask) || (uio->uio_resid & mp->m_blockmask)) { if (uio->uio_offset >= ip->i_d.di_size) { return (0); } return EINVAL; } } if (uio->uio_resid == 0) return 0; n = XFS_MAXIOFFSET(mp) - uio->uio_offset; if (n <= 0) return EFBIG; size = (n < uio->uio_resid)? n : uio->uio_resid; if (XFS_FORCED_SHUTDOWN(mp)) { return EIO; } xfs_ilock(ip, XFS_IOLOCK_SHARED); #ifdef XXX if (DM_EVENT_ENABLED(BHV_TO_VNODE(bdp)->v_vfsp, ip, DM_EVENT_READ) && !(ioflags & IO_INVIS)) { int error; 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), uio->uio_offset, size, dmflags, &locktype); if (error) { xfs_iunlock(ip, XFS_IOLOCK_SHARED); return (error); } } #endif ret = xfs_read_file(mp, ip, uio, ioflags); xfs_iunlock(ip, XFS_IOLOCK_SHARED); XFS_STATS_ADD(xs_read_bytes, ret); if (likely((ioflags & IO_INVIS) == 0)) { xfs_ichgtime(ip, XFS_ICHGTIME_ACC); } return ret; }
ssize_t /* bytes read, or (-) error */ xfs_read( xfs_inode_t *ip, struct kiocb *iocb, const struct iovec *iovp, unsigned int segs, loff_t *offset, int ioflags) { struct file *file = iocb->ki_filp; struct inode *inode = file->f_mapping->host; xfs_mount_t *mp = ip->i_mount; size_t size = 0; ssize_t ret = 0; xfs_fsize_t n; unsigned long seg; 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 (unlikely(ioflags & IO_ISDIRECT)) { xfs_buftarg_t *target = XFS_IS_REALTIME_INODE(ip) ? mp->m_rtdev_targp : mp->m_ddev_targp; if ((*offset & target->bt_smask) || (size & target->bt_smask)) { if (*offset == ip->i_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 (unlikely(ioflags & IO_ISDIRECT)) mutex_lock(&inode->i_mutex); xfs_ilock(ip, XFS_IOLOCK_SHARED); if (DM_EVENT_ENABLED(ip, DM_EVENT_READ) && !(ioflags & IO_INVIS)) { int dmflags = FILP_DELAY_FLAG(file) | DM_SEM_FLAG_RD(ioflags); int iolock = XFS_IOLOCK_SHARED; ret = -XFS_SEND_DATA(mp, DM_EVENT_READ, ip, *offset, size, dmflags, &iolock); if (ret) { xfs_iunlock(ip, XFS_IOLOCK_SHARED); if (unlikely(ioflags & IO_ISDIRECT)) mutex_unlock(&inode->i_mutex); return ret; } } if (unlikely(ioflags & IO_ISDIRECT)) { if (inode->i_mapping->nrpages) ret = -xfs_flushinval_pages(ip, (*offset & PAGE_CACHE_MASK), -1, FI_REMAPF_LOCKED); mutex_unlock(&inode->i_mutex); if (ret) { xfs_iunlock(ip, XFS_IOLOCK_SHARED); return ret; } } xfs_rw_enter_trace(XFS_READ_ENTER, ip, (void *)iovp, segs, *offset, ioflags); iocb->ki_pos = *offset; ret = generic_file_aio_read(iocb, iovp, segs, *offset); if (ret == -EIOCBQUEUED && !(ioflags & IO_ISAIO)) ret = wait_on_sync_kiocb(iocb); if (ret > 0) XFS_STATS_ADD(xs_read_bytes, ret); xfs_iunlock(ip, XFS_IOLOCK_SHARED); return ret; }