diff options
Diffstat (limited to 'fs/xfs/linux-2.6/xfs_file.c')
-rw-r--r-- | fs/xfs/linux-2.6/xfs_file.c | 723 |
1 files changed, 723 insertions, 0 deletions
diff --git a/fs/xfs/linux-2.6/xfs_file.c b/fs/xfs/linux-2.6/xfs_file.c index 3805ada9874..51fc510828a 100644 --- a/fs/xfs/linux-2.6/xfs_file.c +++ b/fs/xfs/linux-2.6/xfs_file.c @@ -16,6 +16,7 @@ * 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" @@ -34,16 +35,738 @@ #include "xfs_dir2_sf.h" #include "xfs_dinode.h" #include "xfs_inode.h" +#include "xfs_bmap.h" #include "xfs_error.h" #include "xfs_rw.h" #include "xfs_vnodeops.h" #include "xfs_da_btree.h" #include "xfs_ioctl.h" +#include "xfs_trace.h" #include <linux/dcache.h> static const struct vm_operations_struct xfs_file_vm_ops; +/* + * 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 xfs_inode *ip, /* inode */ + loff_t pos, /* offset in file */ + size_t count) /* size of data to zero */ +{ + struct page *page; + struct address_space *mapping; + int status; + + mapping = VFS_I(ip)->i_mapping; + do { + unsigned offset, bytes; + void *fsdata; + + offset = (pos & (PAGE_CACHE_SIZE -1)); /* Within page */ + bytes = PAGE_CACHE_SIZE - offset; + if (bytes > count) + bytes = count; + + status = pagecache_write_begin(NULL, mapping, pos, bytes, + AOP_FLAG_UNINTERRUPTIBLE, + &page, &fsdata); + if (status) + break; + + zero_user(page, offset, bytes); + + status = pagecache_write_end(NULL, mapping, pos, bytes, bytes, + page, fsdata); + WARN_ON(status <= 0); /* can't return less than zero! */ + pos += bytes; + count -= bytes; + status = 0; + } while (count); + + return (-status); +} + +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; + } + } + + trace_xfs_file_read(ip, size, *offset, ioflags); + + iocb->ki_pos = *offset; + ret = generic_file_aio_read(iocb, iovp, segs, *offset); + if (ret > 0) + XFS_STATS_ADD(xs_read_bytes, ret); + + xfs_iunlock(ip, XFS_IOLOCK_SHARED); + return ret; +} + +ssize_t +xfs_splice_read( + xfs_inode_t *ip, + struct file *infilp, + loff_t *ppos, + struct pipe_inode_info *pipe, + size_t count, + int flags, + int ioflags) +{ + xfs_mount_t *mp = ip->i_mount; + ssize_t ret; + + XFS_STATS_INC(xs_read_calls); + if (XFS_FORCED_SHUTDOWN(ip->i_mount)) + return -EIO; + + xfs_ilock(ip, XFS_IOLOCK_SHARED); + + if (DM_EVENT_ENABLED(ip, DM_EVENT_READ) && !(ioflags & IO_INVIS)) { + int iolock = XFS_IOLOCK_SHARED; + int error; + + error = XFS_SEND_DATA(mp, DM_EVENT_READ, ip, *ppos, count, + FILP_DELAY_FLAG(infilp), &iolock); + if (error) { + xfs_iunlock(ip, XFS_IOLOCK_SHARED); + return -error; + } + } + + trace_xfs_file_splice_read(ip, count, *ppos, ioflags); + + ret = generic_file_splice_read(infilp, ppos, pipe, count, flags); + if (ret > 0) + XFS_STATS_ADD(xs_read_bytes, ret); + + xfs_iunlock(ip, XFS_IOLOCK_SHARED); + return ret; +} + +ssize_t +xfs_splice_write( + xfs_inode_t *ip, + struct pipe_inode_info *pipe, + struct file *outfilp, + loff_t *ppos, + size_t count, + int flags, + int ioflags) +{ + xfs_mount_t *mp = ip->i_mount; + ssize_t ret; + struct inode *inode = outfilp->f_mapping->host; + xfs_fsize_t isize, new_size; + + XFS_STATS_INC(xs_write_calls); + if (XFS_FORCED_SHUTDOWN(ip->i_mount)) + return -EIO; + + xfs_ilock(ip, XFS_IOLOCK_EXCL); + + if (DM_EVENT_ENABLED(ip, DM_EVENT_WRITE) && !(ioflags & IO_INVIS)) { + int iolock = XFS_IOLOCK_EXCL; + int error; + + error = XFS_SEND_DATA(mp, DM_EVENT_WRITE, ip, *ppos, count, + FILP_DELAY_FLAG(outfilp), &iolock); + if (error) { + xfs_iunlock(ip, XFS_IOLOCK_EXCL); + return -error; + } + } + + new_size = *ppos + count; + + xfs_ilock(ip, XFS_ILOCK_EXCL); + if (new_size > ip->i_size) + ip->i_new_size = new_size; + xfs_iunlock(ip, XFS_ILOCK_EXCL); + + trace_xfs_file_splice_write(ip, count, *ppos, ioflags); + + ret = generic_file_splice_write(pipe, outfilp, ppos, count, flags); + if (ret > 0) + XFS_STATS_ADD(xs_write_bytes, ret); + + isize = i_size_read(inode); + if (unlikely(ret < 0 && ret != -EFAULT && *ppos > isize)) + *ppos = isize; + + if (*ppos > ip->i_size) { + xfs_ilock(ip, XFS_ILOCK_EXCL); + if (*ppos > ip->i_size) + ip->i_size = *ppos; + xfs_iunlock(ip, XFS_ILOCK_EXCL); + } + + if (ip->i_new_size) { + xfs_ilock(ip, XFS_ILOCK_EXCL); + ip->i_new_size = 0; + if (ip->i_d.di_size > ip->i_size) + ip->i_d.di_size = ip->i_size; + xfs_iunlock(ip, XFS_ILOCK_EXCL); + } + xfs_iunlock(ip, XFS_IOLOCK_EXCL); + 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( + xfs_inode_t *ip, + xfs_fsize_t offset, + xfs_fsize_t isize) +{ + xfs_fileoff_t last_fsb; + xfs_mount_t *mp = ip->i_mount; + int nimaps; + int zero_offset; + int zero_len; + int error = 0; + xfs_bmbt_irec_t imap; + + ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL)); + + 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(NULL, ip, 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(ip, XFS_ILOCK_EXCL); + + zero_len = mp->m_sb.sb_blocksize - zero_offset; + if (isize + zero_len > offset) + zero_len = offset - isize; + error = xfs_iozero(ip, isize, zero_len); + + xfs_ilock(ip, XFS_ILOCK_EXCL); + 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( + xfs_inode_t *ip, + xfs_off_t offset, /* starting I/O offset */ + xfs_fsize_t isize) /* current inode size */ +{ + xfs_mount_t *mp = ip->i_mount; + xfs_fileoff_t start_zero_fsb; + xfs_fileoff_t end_zero_fsb; + xfs_fileoff_t zero_count_fsb; + xfs_fileoff_t last_fsb; + xfs_fileoff_t zero_off; + xfs_fsize_t zero_len; + int nimaps; + int error = 0; + xfs_bmbt_irec_t imap; + + ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL|XFS_IOLOCK_EXCL)); + ASSERT(offset > isize); + + /* + * 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, offset, isize); + if (error) { + ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL|XFS_IOLOCK_EXCL)); + 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(NULL, ip, start_zero_fsb, zero_count_fsb, + 0, NULL, 0, &imap, &nimaps, NULL, NULL); + if (error) { + ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL|XFS_IOLOCK_EXCL)); + 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(ip, XFS_ILOCK_EXCL); + + zero_off = XFS_FSB_TO_B(mp, start_zero_fsb); + zero_len = XFS_FSB_TO_B(mp, imap.br_blockcount); + + if ((zero_off + zero_len) > offset) + zero_len = offset - zero_off; + + error = xfs_iozero(ip, zero_off, zero_len); + if (error) { + goto out_lock; + } + + start_zero_fsb = imap.br_startoff + imap.br_blockcount; + ASSERT(start_zero_fsb <= (end_zero_fsb + 1)); + + xfs_ilock(ip, XFS_ILOCK_EXCL); + } + + return 0; + +out_lock: + xfs_ilock(ip, XFS_ILOCK_EXCL); + ASSERT(error >= 0); + return error; +} + +ssize_t /* bytes written, or (-) error */ +xfs_write( + struct xfs_inode *xip, + struct kiocb *iocb, + const struct iovec *iovp, + unsigned int nsegs, + loff_t *offset, + int ioflags) +{ + struct file *file = iocb->ki_filp; + struct address_space *mapping = file->f_mapping; + struct inode *inode = mapping->host; + unsigned long segs = nsegs; + xfs_mount_t *mp; + ssize_t ret = 0, error = 0; + xfs_fsize_t isize, new_size; + int iolock; + int eventsent = 0; + size_t ocount = 0, count; + loff_t pos; + int need_i_mutex; + + XFS_STATS_INC(xs_write_calls); + + error = generic_segment_checks(iovp, &segs, &ocount, VERIFY_READ); + if (error) + return error; + + count = ocount; + pos = *offset; + + if (count == 0) + return 0; + + mp = xip->i_mount; + + xfs_wait_for_freeze(mp, SB_FREEZE_WRITE); + + if (XFS_FORCED_SHUTDOWN(mp)) + return -EIO; + +relock: + if (ioflags & IO_ISDIRECT) { + iolock = XFS_IOLOCK_SHARED; + need_i_mutex = 0; + } else { + iolock = XFS_IOLOCK_EXCL; + need_i_mutex = 1; + mutex_lock(&inode->i_mutex); + } + + xfs_ilock(xip, XFS_ILOCK_EXCL|iolock); + +start: + error = -generic_write_checks(file, &pos, &count, + S_ISBLK(inode->i_mode)); + if (error) { + xfs_iunlock(xip, XFS_ILOCK_EXCL|iolock); + goto out_unlock_mutex; + } + + if ((DM_EVENT_ENABLED(xip, DM_EVENT_WRITE) && + !(ioflags & IO_INVIS) && !eventsent)) { + int dmflags = FILP_DELAY_FLAG(file); + + if (need_i_mutex) + dmflags |= DM_FLAGS_IMUX; + + xfs_iunlock(xip, XFS_ILOCK_EXCL); + error = XFS_SEND_DATA(xip->i_mount, DM_EVENT_WRITE, xip, + pos, count, dmflags, &iolock); + if (error) { + goto out_unlock_internal; + } + xfs_ilock(xip, XFS_ILOCK_EXCL); + eventsent = 1; + + /* + * The iolock was dropped and reacquired 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) && pos != xip->i_size) + goto start; + } + + if (ioflags & IO_ISDIRECT) { + xfs_buftarg_t *target = + XFS_IS_REALTIME_INODE(xip) ? + mp->m_rtdev_targp : mp->m_ddev_targp; + + if ((pos & target->bt_smask) || (count & target->bt_smask)) { + xfs_iunlock(xip, XFS_ILOCK_EXCL|iolock); + return XFS_ERROR(-EINVAL); + } + + if (!need_i_mutex && (mapping->nrpages || pos > xip->i_size)) { + xfs_iunlock(xip, XFS_ILOCK_EXCL|iolock); + iolock = XFS_IOLOCK_EXCL; + need_i_mutex = 1; + mutex_lock(&inode->i_mutex); + xfs_ilock(xip, XFS_ILOCK_EXCL|iolock); + goto start; + } + } + + new_size = pos + count; + if (new_size > xip->i_size) + xip->i_new_size = new_size; + + if (likely(!(ioflags & IO_INVIS))) + file_update_time(file); + + /* + * 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 (pos > xip->i_size) { + error = xfs_zero_eof(xip, pos, xip->i_size); + if (error) { + xfs_iunlock(xip, XFS_ILOCK_EXCL); + goto out_unlock_internal; + } + } + 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. + */ + error = -file_remove_suid(file); + if (unlikely(error)) + goto out_unlock_internal; + + /* We can write back this queue in page reclaim */ + current->backing_dev_info = mapping->backing_dev_info; + + if ((ioflags & IO_ISDIRECT)) { + if (mapping->nrpages) { + WARN_ON(need_i_mutex == 0); + error = xfs_flushinval_pages(xip, + (pos & PAGE_CACHE_MASK), + -1, FI_REMAPF_LOCKED); + if (error) + goto out_unlock_internal; + } + + if (need_i_mutex) { + /* demote the lock now the cached pages are gone */ + xfs_ilock_demote(xip, XFS_IOLOCK_EXCL); + mutex_unlock(&inode->i_mutex); + + iolock = XFS_IOLOCK_SHARED; + need_i_mutex = 0; + } + + trace_xfs_file_direct_write(xip, count, *offset, ioflags); + ret = generic_file_direct_write(iocb, iovp, + &segs, pos, offset, count, ocount); + + /* + * direct-io write to a hole: fall through to buffered I/O + * for completing the rest of the request. + */ + if (ret >= 0 && ret != count) { + XFS_STATS_ADD(xs_write_bytes, ret); + + pos += ret; + count -= ret; + + ioflags &= ~IO_ISDIRECT; + xfs_iunlock(xip, iolock); + goto relock; + } + } else { + int enospc = 0; + ssize_t ret2 = 0; + +write_retry: + trace_xfs_file_buffered_write(xip, count, *offset, ioflags); + ret2 = generic_file_buffered_write(iocb, iovp, segs, + pos, offset, count, ret); + /* + * if we just got an ENOSPC, flush the inode now we + * aren't holding any page locks and retry *once* + */ + if (ret2 == -ENOSPC && !enospc) { + error = xfs_flush_pages(xip, 0, -1, 0, FI_NONE); + if (error) + goto out_unlock_internal; + enospc = 1; + goto write_retry; + } + ret = ret2; + } + + current->backing_dev_info = NULL; + + isize = i_size_read(inode); + if (unlikely(ret < 0 && ret != -EFAULT && *offset > isize)) + *offset = isize; + + if (*offset > xip->i_size) { + xfs_ilock(xip, XFS_ILOCK_EXCL); + if (*offset > xip->i_size) + xip->i_size = *offset; + xfs_iunlock(xip, XFS_ILOCK_EXCL); + } + + if (ret == -ENOSPC && + DM_EVENT_ENABLED(xip, DM_EVENT_NOSPACE) && !(ioflags & IO_INVIS)) { + xfs_iunlock(xip, iolock); + if (need_i_mutex) + mutex_unlock(&inode->i_mutex); + error = XFS_SEND_NAMESP(xip->i_mount, DM_EVENT_NOSPACE, xip, + DM_RIGHT_NULL, xip, DM_RIGHT_NULL, NULL, NULL, + 0, 0, 0); /* Delay flag intentionally unused */ + if (need_i_mutex) + mutex_lock(&inode->i_mutex); + xfs_ilock(xip, iolock); + if (error) + goto out_unlock_internal; + goto start; + } + + error = -ret; + if (ret <= 0) + goto out_unlock_internal; + + XFS_STATS_ADD(xs_write_bytes, ret); + + /* Handle various SYNC-type writes */ + if ((file->f_flags & O_DSYNC) || IS_SYNC(inode)) { + loff_t end = pos + ret - 1; + int error2; + + xfs_iunlock(xip, iolock); + if (need_i_mutex) + mutex_unlock(&inode->i_mutex); + + error2 = filemap_write_and_wait_range(mapping, pos, end); + if (!error) + error = error2; + if (need_i_mutex) + mutex_lock(&inode->i_mutex); + xfs_ilock(xip, iolock); + + error2 = xfs_fsync(xip); + if (!error) + error = error2; + } + + out_unlock_internal: + if (xip->i_new_size) { + xfs_ilock(xip, XFS_ILOCK_EXCL); + xip->i_new_size = 0; + /* + * If this was a direct or synchronous I/O that failed (such + * as ENOSPC) then part of the I/O may have been written to + * disk before the error occured. In this case the on-disk + * file size may have been adjusted beyond the in-memory file + * size and now needs to be truncated back. + */ + if (xip->i_d.di_size > xip->i_size) + xip->i_d.di_size = xip->i_size; + xfs_iunlock(xip, XFS_ILOCK_EXCL); + } + xfs_iunlock(xip, iolock); + out_unlock_mutex: + if (need_i_mutex) + mutex_unlock(&inode->i_mutex); + return -error; +} + STATIC ssize_t xfs_file_aio_read( struct kiocb *iocb, |