diff options
Diffstat (limited to 'fs/xfs/xfs_file.c')
| -rw-r--r-- | fs/xfs/xfs_file.c | 1096 |
1 files changed, 1096 insertions, 0 deletions
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c new file mode 100644 index 00000000000..7f7b42469ea --- /dev/null +++ b/fs/xfs/xfs_file.c @@ -0,0 +1,1096 @@ +/* + * Copyright (c) 2000-2005 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_sb.h" +#include "xfs_ag.h" +#include "xfs_trans.h" +#include "xfs_mount.h" +#include "xfs_bmap_btree.h" +#include "xfs_alloc.h" +#include "xfs_dinode.h" +#include "xfs_inode.h" +#include "xfs_inode_item.h" +#include "xfs_bmap.h" +#include "xfs_error.h" +#include "xfs_vnodeops.h" +#include "xfs_da_btree.h" +#include "xfs_ioctl.h" +#include "xfs_trace.h" + +#include <linux/dcache.h> +#include <linux/falloc.h> + +static const struct vm_operations_struct xfs_file_vm_ops; + +/* + * Locking primitives for read and write IO paths to ensure we consistently use + * and order the inode->i_mutex, ip->i_lock and ip->i_iolock. + */ +static inline void +xfs_rw_ilock( + struct xfs_inode *ip, + int type) +{ + if (type & XFS_IOLOCK_EXCL) + mutex_lock(&VFS_I(ip)->i_mutex); + xfs_ilock(ip, type); +} + +static inline void +xfs_rw_iunlock( + struct xfs_inode *ip, + int type) +{ + xfs_iunlock(ip, type); + if (type & XFS_IOLOCK_EXCL) + mutex_unlock(&VFS_I(ip)->i_mutex); +} + +static inline void +xfs_rw_ilock_demote( + struct xfs_inode *ip, + int type) +{ + xfs_ilock_demote(ip, type); + if (type & XFS_IOLOCK_EXCL) + mutex_unlock(&VFS_I(ip)->i_mutex); +} + +/* + * 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); +} + +STATIC int +xfs_file_fsync( + struct file *file, + loff_t start, + loff_t end, + int datasync) +{ + struct inode *inode = file->f_mapping->host; + struct xfs_inode *ip = XFS_I(inode); + struct xfs_mount *mp = ip->i_mount; + struct xfs_trans *tp; + int error = 0; + int log_flushed = 0; + + trace_xfs_file_fsync(ip); + + error = filemap_write_and_wait_range(inode->i_mapping, start, end); + if (error) + return error; + + if (XFS_FORCED_SHUTDOWN(mp)) + return -XFS_ERROR(EIO); + + xfs_iflags_clear(ip, XFS_ITRUNCATED); + + xfs_ilock(ip, XFS_IOLOCK_SHARED); + xfs_ioend_wait(ip); + xfs_iunlock(ip, XFS_IOLOCK_SHARED); + + if (mp->m_flags & XFS_MOUNT_BARRIER) { + /* + * If we have an RT and/or log subvolume we need to make sure + * to flush the write cache the device used for file data + * first. This is to ensure newly written file data make + * it to disk before logging the new inode size in case of + * an extending write. + */ + if (XFS_IS_REALTIME_INODE(ip)) + xfs_blkdev_issue_flush(mp->m_rtdev_targp); + else if (mp->m_logdev_targp != mp->m_ddev_targp) + xfs_blkdev_issue_flush(mp->m_ddev_targp); + } + + /* + * We always need to make sure that the required inode state is safe on + * disk. The inode might be clean but we still might need to force the + * log because of committed transactions that haven't hit the disk yet. + * Likewise, there could be unflushed non-transactional changes to the + * inode core that have to go to disk and this requires us to issue + * a synchronous transaction to capture these changes correctly. + * + * This code relies on the assumption that if the i_update_core field + * of the inode is clear and the inode is unpinned then it is clean + * and no action is required. + */ + xfs_ilock(ip, XFS_ILOCK_SHARED); + + /* + * First check if the VFS inode is marked dirty. All the dirtying + * of non-transactional updates no goes through mark_inode_dirty*, + * which allows us to distinguish beteeen pure timestamp updates + * and i_size updates which need to be caught for fdatasync. + * After that also theck for the dirty state in the XFS inode, which + * might gets cleared when the inode gets written out via the AIL + * or xfs_iflush_cluster. + */ + if (((inode->i_state & I_DIRTY_DATASYNC) || + ((inode->i_state & I_DIRTY_SYNC) && !datasync)) && + ip->i_update_core) { + /* + * Kick off a transaction to log the inode core to get the + * updates. The sync transaction will also force the log. + */ + xfs_iunlock(ip, XFS_ILOCK_SHARED); + tp = xfs_trans_alloc(mp, XFS_TRANS_FSYNC_TS); + error = xfs_trans_reserve(tp, 0, + XFS_FSYNC_TS_LOG_RES(mp), 0, 0, 0); + if (error) { + xfs_trans_cancel(tp, 0); + return -error; + } + xfs_ilock(ip, XFS_ILOCK_EXCL); + + /* + * Note - it's possible that we might have pushed ourselves out + * of the way during trans_reserve which would flush the inode. + * But there's no guarantee that the inode buffer has actually + * gone out yet (it's delwri). Plus the buffer could be pinned + * anyway if it's part of an inode in another recent + * transaction. So we play it safe and fire off the + * transaction anyway. + */ + xfs_trans_ijoin(tp, ip); + xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE); + xfs_trans_set_sync(tp); + error = _xfs_trans_commit(tp, 0, &log_flushed); + + xfs_iunlock(ip, XFS_ILOCK_EXCL); + } else { + /* + * Timestamps/size haven't changed since last inode flush or + * inode transaction commit. That means either nothing got + * written or a transaction committed which caught the updates. + * If the latter happened and the transaction hasn't hit the + * disk yet, the inode will be still be pinned. If it is, + * force the log. + */ + if (xfs_ipincount(ip)) { + error = _xfs_log_force_lsn(mp, + ip->i_itemp->ili_last_lsn, + XFS_LOG_SYNC, &log_flushed); + } + xfs_iunlock(ip, XFS_ILOCK_SHARED); + } + + /* + * If we only have a single device, and the log force about was + * a no-op we might have to flush the data device cache here. + * This can only happen for fdatasync/O_DSYNC if we were overwriting + * an already allocated file and thus do not have any metadata to + * commit. + */ + if ((mp->m_flags & XFS_MOUNT_BARRIER) && + mp->m_logdev_targp == mp->m_ddev_targp && + !XFS_IS_REALTIME_INODE(ip) && + !log_flushed) + xfs_blkdev_issue_flush(mp->m_ddev_targp); + + return -error; +} + +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)) { + xfs_rw_ilock(ip, XFS_IOLOCK_EXCL); + + if (inode->i_mapping->nrpages) { + ret = -xfs_flushinval_pages(ip, + (iocb->ki_pos & PAGE_CACHE_MASK), + -1, FI_REMAPF_LOCKED); + if (ret) { + xfs_rw_iunlock(ip, XFS_IOLOCK_EXCL); + return ret; + } + } + xfs_rw_ilock_demote(ip, XFS_IOLOCK_EXCL); + } else + xfs_rw_ilock(ip, XFS_IOLOCK_SHARED); + + 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_rw_iunlock(ip, XFS_IOLOCK_SHARED); + return ret; +} + +STATIC ssize_t +xfs_file_splice_read( + struct file *infilp, + loff_t *ppos, + struct pipe_inode_info *pipe, + size_t count, + unsigned int flags) +{ + struct xfs_inode *ip = XFS_I(infilp->f_mapping->host); + int ioflags = 0; + ssize_t ret; + + XFS_STATS_INC(xs_read_calls); + + if (infilp->f_mode & FMODE_NOCMTIME) + ioflags |= IO_INVIS; + + if (XFS_FORCED_SHUTDOWN(ip->i_mount)) + return -EIO; + + xfs_rw_ilock(ip, XFS_IOLOCK_SHARED); + + 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_rw_iunlock(ip, XFS_IOLOCK_SHARED); + return ret; +} + +STATIC void +xfs_aio_write_isize_update( + struct inode *inode, + loff_t *ppos, + ssize_t bytes_written) +{ + struct xfs_inode *ip = XFS_I(inode); + xfs_fsize_t isize = i_size_read(inode); + + if (bytes_written > 0) + XFS_STATS_ADD(xs_write_bytes, bytes_written); + + if (unlikely(bytes_written < 0 && bytes_written != -EFAULT && + *ppos > isize)) + *ppos = isize; + + if (*ppos > ip->i_size) { + xfs_rw_ilock(ip, XFS_ILOCK_EXCL); + if (*ppos > ip->i_size) + ip->i_size = *ppos; + xfs_rw_iunlock(ip, XFS_ILOCK_EXCL); + } +} + +/* + * 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 occurred. 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. + */ +STATIC void +xfs_aio_write_newsize_update( + struct xfs_inode *ip) +{ + if (ip->i_new_size) { + xfs_rw_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_rw_iunlock(ip, XFS_ILOCK_EXCL); + } +} + +/* + * xfs_file_splice_write() does not use xfs_rw_ilock() because + * generic_file_splice_write() takes the i_mutex itself. This, in theory, + * couuld cause lock inversions between the aio_write path and the splice path + * if someone is doing concurrent splice(2) based writes and write(2) based + * writes to the same inode. The only real way to fix this is to re-implement + * the generic code here with correct locking orders. + */ +STATIC ssize_t +xfs_file_splice_write( + struct pipe_inode_info *pipe, + struct file *outfilp, + loff_t *ppos, + size_t count, + unsigned int flags) +{ + struct inode *inode = outfilp->f_mapping->host; + struct xfs_inode *ip = XFS_I(inode); + xfs_fsize_t new_size; + int ioflags = 0; + ssize_t ret; + + XFS_STATS_INC(xs_write_calls); + + if (outfilp->f_mode & FMODE_NOCMTIME) + ioflags |= IO_INVIS; + + if (XFS_FORCED_SHUTDOWN(ip->i_mount)) + return -EIO; + + xfs_ilock(ip, XFS_IOLOCK_EXCL); + + 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); + + xfs_aio_write_isize_update(inode, ppos, ret); + xfs_aio_write_newsize_update(ip); + 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); + 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); + 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; +} + +/* + * Common pre-write limit and setup checks. + * + * Returns with iolock held according to @iolock. + */ +STATIC ssize_t +xfs_file_aio_write_checks( + struct file *file, + loff_t *pos, + size_t *count, + int *iolock) +{ + struct inode *inode = file->f_mapping->host; + struct xfs_inode *ip = XFS_I(inode); + xfs_fsize_t new_size; + int error = 0; + + error = generic_write_checks(file, pos, count, S_ISBLK(inode->i_mode)); + if (error) { + xfs_rw_iunlock(ip, XFS_ILOCK_EXCL | *iolock); + *iolock = 0; + return error; + } + + new_size = *pos + *count; + if (new_size > ip->i_size) + ip->i_new_size = new_size; + + if (likely(!(file->f_mode & FMODE_NOCMTIME))) + file_update_time(file); + + /* + * If the offset is beyond the size of the file, we need to zero any + * blocks that fall between the existing EOF and the start of this + * write. + */ + if (*pos > ip->i_size) + error = -xfs_zero_eof(ip, *pos, ip->i_size); + + xfs_rw_iunlock(ip, XFS_ILOCK_EXCL); + if (error) + return error; + + /* + * 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. + */ + return file_remove_suid(file); + +} + +/* + * xfs_file_dio_aio_write - handle direct IO writes + * + * Lock the inode appropriately to prepare for and issue a direct IO write. + * By separating it from the buffered write path we remove all the tricky to + * follow locking changes and looping. + * + * If there are cached pages or we're extending the file, we need IOLOCK_EXCL + * until we're sure the bytes at the new EOF have been zeroed and/or the cached + * pages are flushed out. + * + * In most cases the direct IO writes will be done holding IOLOCK_SHARED + * allowing them to be done in parallel with reads and other direct IO writes. + * However, if the IO is not aligned to filesystem blocks, the direct IO layer + * needs to do sub-block zeroing and that requires serialisation against other + * direct IOs to the same block. In this case we need to serialise the + * submission of the unaligned IOs so that we don't get racing block zeroing in + * the dio layer. To avoid the problem with aio, we also need to wait for + * outstanding IOs to complete so that unwritten extent conversion is completed + * before we try to map the overlapping block. This is currently implemented by + * hitting it with a big hammer (i.e. xfs_ioend_wait()). + * + * Returns with locks held indicated by @iolock and errors indicated by + * negative return values. + */ +STATIC ssize_t +xfs_file_dio_aio_write( + struct kiocb *iocb, + const struct iovec *iovp, + unsigned long nr_segs, + loff_t pos, + size_t ocount, + int *iolock) +{ + struct file *file = iocb->ki_filp; + struct address_space *mapping = file->f_mapping; + struct inode *inode = mapping->host; + struct xfs_inode *ip = XFS_I(inode); + struct xfs_mount *mp = ip->i_mount; + ssize_t ret = 0; + size_t count = ocount; + int unaligned_io = 0; + struct xfs_buftarg *target = XFS_IS_REALTIME_INODE(ip) ? + mp->m_rtdev_targp : mp->m_ddev_targp; + + *iolock = 0; + if ((pos & target->bt_smask) || (count & target->bt_smask)) + return -XFS_ERROR(EINVAL); + + if ((pos & mp->m_blockmask) || ((pos + count) & mp->m_blockmask)) + unaligned_io = 1; + + if (unaligned_io || mapping->nrpages || pos > ip->i_size) + *iolock = XFS_IOLOCK_EXCL; + else + *iolock = XFS_IOLOCK_SHARED; + xfs_rw_ilock(ip, XFS_ILOCK_EXCL | *iolock); + + ret = xfs_file_aio_write_checks(file, &pos, &count, iolock); + if (ret) + return ret; + + if (mapping->nrpages) { + WARN_ON(*iolock != XFS_IOLOCK_EXCL); + ret = -xfs_flushinval_pages(ip, (pos & PAGE_CACHE_MASK), -1, + FI_REMAPF_LOCKED); + if (ret) + return ret; + } + + /* + * If we are doing unaligned IO, wait for all other IO to drain, + * otherwise demote the lock if we had to flush cached pages + */ + if (unaligned_io) + xfs_ioend_wait(ip); + else if (*iolock == XFS_IOLOCK_EXCL) { + xfs_rw_ilock_demote(ip, XFS_IOLOCK_EXCL); + *iolock = XFS_IOLOCK_SHARED; + } + + trace_xfs_file_direct_write(ip, count, iocb->ki_pos, 0); + ret = generic_file_direct_write(iocb, iovp, + &nr_segs, pos, &iocb->ki_pos, count, ocount); + + /* No fallback to buffered IO on errors for XFS. */ + ASSERT(ret < 0 || ret == count); + return ret; +} + +STATIC ssize_t +xfs_file_buffered_aio_write( + struct kiocb *iocb, + const struct iovec *iovp, + unsigned long nr_segs, + loff_t pos, + size_t ocount, + int *iolock) +{ + struct file *file = iocb->ki_filp; + struct address_space *mapping = file->f_mapping; + struct inode *inode = mapping->host; + struct xfs_inode *ip = XFS_I(inode); + ssize_t ret; + int enospc = 0; + size_t count = ocount; + + *iolock = XFS_IOLOCK_EXCL; + xfs_rw_ilock(ip, XFS_ILOCK_EXCL | *iolock); + + ret = xfs_file_aio_write_checks(file, &pos, &count, iolock); + if (ret) + return ret; + + /* We can write back this queue in page reclaim */ + current->backing_dev_info = mapping->backing_dev_info; + +write_retry: + trace_xfs_file_buffered_write(ip, count, iocb->ki_pos, 0); + ret = generic_file_buffered_write(iocb, iovp, nr_segs, + pos, &iocb->ki_pos, count, ret); + /* + * if we just got an ENOSPC, flush the inode now we aren't holding any + * page locks and retry *once* + */ + if (ret == -ENOSPC && !enospc) { + ret = -xfs_flush_pages(ip, 0, -1, 0, FI_NONE); + if (ret) + return ret; + enospc = 1; + goto write_retry; + } + current->backing_dev_info = NULL; + return ret; +} + +STATIC ssize_t +xfs_file_aio_write( + struct kiocb *iocb, + const struct iovec *iovp, + unsigned long nr_segs, + loff_t pos) +{ + struct file *file = iocb->ki_filp; + struct address_space *mapping = file->f_mapping; + struct inode *inode = mapping->host; + struct xfs_inode *ip = XFS_I(inode); + ssize_t ret; + int iolock; + size_t ocount = 0; + + XFS_STATS_INC(xs_write_calls); + + BUG_ON(iocb->ki_pos != pos); + + ret = generic_segment_checks(iovp, &nr_segs, &ocount, VERIFY_READ); + if (ret) + return ret; + + if (ocount == 0) + return 0; + + xfs_wait_for_freeze(ip->i_mount, SB_FREEZE_WRITE); + + if (XFS_FORCED_SHUTDOWN(ip->i_mount)) + return -EIO; + + if (unlikely(file->f_flags & O_DIRECT)) + ret = xfs_file_dio_aio_write(iocb, iovp, nr_segs, pos, + ocount, &iolock); + else + ret = xfs_file_buffered_aio_write(iocb, iovp, nr_segs, pos, + ocount, &iolock); + + xfs_aio_write_isize_update(inode, &iocb->ki_pos, ret); + + if (ret <= 0) + goto out_unlock; + + /* Handle various SYNC-type writes */ + if ((file->f_flags & O_DSYNC) || IS_SYNC(inode)) { + loff_t end = pos + ret - 1; + int error; + + xfs_rw_iunlock(ip, iolock); + error = xfs_file_fsync(file, pos, end, + (file->f_flags & __O_SYNC) ? 0 : 1); + xfs_rw_ilock(ip, iolock); + if (error) + ret = error; + } + +out_unlock: + xfs_aio_write_newsize_update(ip); + xfs_rw_iunlock(ip, iolock); + return ret; +} + +STATIC long +xfs_file_fallocate( + struct file *file, + int mode, + loff_t offset, + loff_t len) +{ + struct inode *inode = file->f_path.dentry->d_inode; + long error; + loff_t new_size = 0; + xfs_flock64_t bf; + xfs_inode_t *ip = XFS_I(inode); + int cmd = XFS_IOC_RESVSP; + int attr_flags = XFS_ATTR_NOLOCK; + + if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE)) + return -EOPNOTSUPP; + + bf.l_whence = 0; + bf.l_start = offset; + bf.l_len = len; + + xfs_ilock(ip, XFS_IOLOCK_EXCL); + + if (mode & FALLOC_FL_PUNCH_HOLE) + cmd = XFS_IOC_UNRESVSP; + + /* check the new inode size is valid before allocating */ + if (!(mode & FALLOC_FL_KEEP_SIZE) && + offset + len > i_size_read(inode)) { + new_size = offset + len; + error = inode_newsize_ok(inode, new_size); + if (error) + goto out_unlock; + } + + if (file->f_flags & O_DSYNC) + attr_flags |= XFS_ATTR_SYNC; + + error = -xfs_change_file_space(ip, cmd, &bf, 0, attr_flags); + if (error) + goto out_unlock; + + /* Change file size if needed */ + if (new_size) { + struct iattr iattr; + + iattr.ia_valid = ATTR_SIZE; + iattr.ia_size = new_size; + error = -xfs_setattr_size(ip, &iattr, XFS_ATTR_NOLOCK); + } + +out_unlock: + xfs_iunlock(ip, XFS_IOLOCK_EXCL); + return error; +} + + +STATIC int +xfs_file_open( + struct inode *inode, + struct file *file) +{ + if (!(file->f_flags & O_LARGEFILE) && i_size_read(inode) > MAX_NON_LFS) + return -EFBIG; + if (XFS_FORCED_SHUTDOWN(XFS_M(inode->i_sb))) + return -EIO; + return 0; +} + +STATIC int +xfs_dir_open( + struct inode *inode, + struct file *file) +{ + struct xfs_inode *ip = XFS_I(inode); + int mode; + int error; + + error = xfs_file_open(inode, file); + if (error) + return error; + + /* + * If there are any blocks, read-ahead block 0 as we're almost + * certain to have the next operation be a read there. + */ + mode = xfs_ilock_map_shared(ip); + if (ip->i_d.di_nextents > 0) + xfs_da_reada_buf(NULL, ip, 0, XFS_DATA_FORK); + xfs_iunlock(ip, mode); + return 0; +} + +STATIC int +xfs_file_release( + struct inode *inode, + struct file *filp) +{ + return -xfs_release(XFS_I(inode)); +} + +STATIC int +xfs_file_readdir( + struct file *filp, + void *dirent, + filldir_t filldir) +{ + struct inode *inode = filp->f_path.dentry->d_inode; + xfs_inode_t *ip = XFS_I(inode); + int error; + size_t bufsize; + + /* + * The Linux API doesn't pass down the total size of the buffer + * we read into down to the filesystem. With the filldir concept + * it's not needed for correct information, but the XFS dir2 leaf + * code wants an estimate of the buffer size to calculate it's + * readahead window and size the buffers used for mapping to + * physical blocks. + * + * Try to give it an estimate that's good enough, maybe at some + * point we can change the ->readdir prototype to include the + * buffer size. For now we use the current glibc buffer size. + */ + bufsize = (size_t)min_t(loff_t, 32768, ip->i_d.di_size); + + error = xfs_readdir(ip, dirent, bufsize, + (xfs_off_t *)&filp->f_pos, filldir); + if (error) + return -error; + return 0; +} + +STATIC int +xfs_file_mmap( + struct file *filp, + struct vm_area_struct *vma) +{ + vma->vm_ops = &xfs_file_vm_ops; + vma->vm_flags |= VM_CAN_NONLINEAR; + + file_accessed(filp); + return 0; +} + +/* + * mmap()d file has taken write protection fault and is being made + * writable. We can set the page state up correctly for a writable + * page, which means we can do correct delalloc accounting (ENOSPC + * checking!) and unwritten extent mapping. + */ +STATIC int +xfs_vm_page_mkwrite( + struct vm_area_struct *vma, + struct vm_fault *vmf) +{ + return block_page_mkwrite(vma, vmf, xfs_get_blocks); +} + +const struct file_operations xfs_file_operations = { + .llseek = generic_file_llseek, + .read = do_sync_read, + .write = do_sync_write, + .aio_read = xfs_file_aio_read, + .aio_write = xfs_file_aio_write, + .splice_read = xfs_file_splice_read, + .splice_write = xfs_file_splice_write, + .unlocked_ioctl = xfs_file_ioctl, +#ifdef CONFIG_COMPAT + .compat_ioctl = xfs_file_compat_ioctl, +#endif + .mmap = xfs_file_mmap, + .open = xfs_file_open, + .release = xfs_file_release, + .fsync = xfs_file_fsync, + .fallocate = xfs_file_fallocate, +}; + +const struct file_operations xfs_dir_file_operations = { + .open = xfs_dir_open, + .read = generic_read_dir, + .readdir = xfs_file_readdir, + .llseek = generic_file_llseek, + .unlocked_ioctl = xfs_file_ioctl, +#ifdef CONFIG_COMPAT + .compat_ioctl = xfs_file_compat_ioctl, +#endif + .fsync = xfs_file_fsync, +}; + +static const struct vm_operations_struct xfs_file_vm_ops = { + .fault = filemap_fault, + .page_mkwrite = xfs_vm_page_mkwrite, +}; |