diff options
Diffstat (limited to 'fs/xfs/linux-2.6/xfs_file.c')
-rw-r--r-- | fs/xfs/linux-2.6/xfs_file.c | 587 |
1 files changed, 361 insertions, 226 deletions
diff --git a/fs/xfs/linux-2.6/xfs_file.c b/fs/xfs/linux-2.6/xfs_file.c index ba8ad422a16..a55c1b46b21 100644 --- a/fs/xfs/linux-2.6/xfs_file.c +++ b/fs/xfs/linux-2.6/xfs_file.c @@ -37,10 +37,45 @@ #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, @@ -262,22 +297,21 @@ xfs_file_aio_read( if (XFS_FORCED_SHUTDOWN(mp)) return -EIO; - if (unlikely(ioflags & IO_ISDIRECT)) - mutex_lock(&inode->i_mutex); - xfs_ilock(ip, XFS_IOLOCK_SHARED); - 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; + } } - mutex_unlock(&inode->i_mutex); - if (ret) { - xfs_iunlock(ip, XFS_IOLOCK_SHARED); - 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); @@ -285,7 +319,7 @@ xfs_file_aio_read( if (ret > 0) XFS_STATS_ADD(xs_read_bytes, ret); - xfs_iunlock(ip, XFS_IOLOCK_SHARED); + xfs_rw_iunlock(ip, XFS_IOLOCK_SHARED); return ret; } @@ -309,7 +343,7 @@ xfs_file_splice_read( if (XFS_FORCED_SHUTDOWN(ip->i_mount)) return -EIO; - xfs_ilock(ip, XFS_IOLOCK_SHARED); + xfs_rw_ilock(ip, XFS_IOLOCK_SHARED); trace_xfs_file_splice_read(ip, count, *ppos, ioflags); @@ -317,10 +351,61 @@ xfs_file_splice_read( if (ret > 0) XFS_STATS_ADD(xs_read_bytes, ret); - xfs_iunlock(ip, XFS_IOLOCK_SHARED); + 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 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. + */ +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, @@ -331,7 +416,7 @@ xfs_file_splice_write( { struct inode *inode = outfilp->f_mapping->host; struct xfs_inode *ip = XFS_I(inode); - xfs_fsize_t isize, new_size; + xfs_fsize_t new_size; int ioflags = 0; ssize_t ret; @@ -355,27 +440,9 @@ xfs_file_splice_write( 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_aio_write_isize_update(inode, ppos, ret); + xfs_aio_write_newsize_update(ip); xfs_iunlock(ip, XFS_IOLOCK_EXCL); return ret; } @@ -562,247 +629,314 @@ out_lock: return error; } +/* + * Common pre-write limit and setup checks. + * + * Returns with iolock held according to @iolock. + */ STATIC ssize_t -xfs_file_aio_write( - struct kiocb *iocb, - const struct iovec *iovp, - unsigned long nr_segs, - loff_t pos) +xfs_file_aio_write_checks( + struct file *file, + loff_t *pos, + size_t *count, + int *iolock) { - struct file *file = iocb->ki_filp; - struct address_space *mapping = file->f_mapping; - struct inode *inode = mapping->host; + struct inode *inode = file->f_mapping->host; struct xfs_inode *ip = XFS_I(inode); - struct xfs_mount *mp = ip->i_mount; - ssize_t ret = 0, error = 0; - int ioflags = 0; - xfs_fsize_t isize, new_size; - int iolock; - size_t ocount = 0, count; - int need_i_mutex; + xfs_fsize_t new_size; + int error = 0; - XFS_STATS_INC(xs_write_calls); + 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; + } - BUG_ON(iocb->ki_pos != pos); + new_size = *pos + *count; + if (new_size > ip->i_size) + ip->i_new_size = new_size; - if (unlikely(file->f_flags & O_DIRECT)) - ioflags |= IO_ISDIRECT; - if (file->f_mode & FMODE_NOCMTIME) - ioflags |= IO_INVIS; + 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); - error = generic_segment_checks(iovp, &nr_segs, &ocount, VERIFY_READ); + xfs_rw_iunlock(ip, XFS_ILOCK_EXCL); if (error) return error; - count = ocount; - if (count == 0) - return 0; - - xfs_wait_for_freeze(mp, SB_FREEZE_WRITE); + /* + * 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); - 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_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; } - xfs_ilock(ip, XFS_ILOCK_EXCL|iolock); - -start: - error = -generic_write_checks(file, &pos, &count, - S_ISBLK(inode->i_mode)); - if (error) { - xfs_iunlock(ip, XFS_ILOCK_EXCL|iolock); - goto out_unlock_mutex; + /* + * 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; } - if (ioflags & IO_ISDIRECT) { - xfs_buftarg_t *target = - XFS_IS_REALTIME_INODE(ip) ? - mp->m_rtdev_targp : mp->m_ddev_targp; + 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); - if ((pos & target->bt_smask) || (count & target->bt_smask)) { - xfs_iunlock(ip, XFS_ILOCK_EXCL|iolock); - return XFS_ERROR(-EINVAL); - } + /* No fallback to buffered IO on errors for XFS. */ + ASSERT(ret < 0 || ret == count); + return ret; +} - if (!need_i_mutex && (mapping->nrpages || pos > ip->i_size)) { - xfs_iunlock(ip, XFS_ILOCK_EXCL|iolock); - iolock = XFS_IOLOCK_EXCL; - need_i_mutex = 1; - mutex_lock(&inode->i_mutex); - xfs_ilock(ip, XFS_ILOCK_EXCL|iolock); - goto start; - } - } +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; - new_size = pos + count; - if (new_size > ip->i_size) - ip->i_new_size = new_size; + *iolock = XFS_IOLOCK_EXCL; + xfs_rw_ilock(ip, XFS_ILOCK_EXCL | *iolock); - if (likely(!(ioflags & IO_INVIS))) - file_update_time(file); + 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 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 we just got an ENOSPC, flush the inode now we aren't holding any + * page locks and retry *once* */ - - if (pos > ip->i_size) { - error = xfs_zero_eof(ip, pos, ip->i_size); - if (error) { - xfs_iunlock(ip, XFS_ILOCK_EXCL); - goto out_unlock_internal; - } + if (ret == -ENOSPC && !enospc) { + ret = -xfs_flush_pages(ip, 0, -1, 0, FI_NONE); + if (ret) + return ret; + enospc = 1; + goto write_retry; } - xfs_iunlock(ip, XFS_ILOCK_EXCL); + current->backing_dev_info = NULL; + return ret; +} - /* - * 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; +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; - /* We can write back this queue in page reclaim */ - current->backing_dev_info = mapping->backing_dev_info; + XFS_STATS_INC(xs_write_calls); - if ((ioflags & IO_ISDIRECT)) { - if (mapping->nrpages) { - WARN_ON(need_i_mutex == 0); - error = xfs_flushinval_pages(ip, - (pos & PAGE_CACHE_MASK), - -1, FI_REMAPF_LOCKED); - if (error) - goto out_unlock_internal; - } + BUG_ON(iocb->ki_pos != pos); - if (need_i_mutex) { - /* demote the lock now the cached pages are gone */ - xfs_ilock_demote(ip, XFS_IOLOCK_EXCL); - mutex_unlock(&inode->i_mutex); + ret = generic_segment_checks(iovp, &nr_segs, &ocount, VERIFY_READ); + if (ret) + return ret; - iolock = XFS_IOLOCK_SHARED; - need_i_mutex = 0; - } + if (ocount == 0) + return 0; - trace_xfs_file_direct_write(ip, count, iocb->ki_pos, ioflags); - ret = generic_file_direct_write(iocb, iovp, - &nr_segs, pos, &iocb->ki_pos, count, ocount); + xfs_wait_for_freeze(ip->i_mount, SB_FREEZE_WRITE); - /* - * 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); + if (XFS_FORCED_SHUTDOWN(ip->i_mount)) + return -EIO; - pos += ret; - count -= ret; + 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); - ioflags &= ~IO_ISDIRECT; - xfs_iunlock(ip, iolock); - goto relock; - } - } else { - int enospc = 0; - ssize_t ret2 = 0; + xfs_aio_write_isize_update(inode, &iocb->ki_pos, ret); -write_retry: - trace_xfs_file_buffered_write(ip, count, iocb->ki_pos, ioflags); - ret2 = 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 (ret2 == -ENOSPC && !enospc) { - error = xfs_flush_pages(ip, 0, -1, 0, FI_NONE); - if (error) - goto out_unlock_internal; - enospc = 1; - goto write_retry; - } - ret = ret2; - } + if (ret <= 0) + goto out_unlock; - current->backing_dev_info = NULL; + /* Handle various SYNC-type writes */ + if ((file->f_flags & O_DSYNC) || IS_SYNC(inode)) { + loff_t end = pos + ret - 1; + int error, error2; - isize = i_size_read(inode); - if (unlikely(ret < 0 && ret != -EFAULT && iocb->ki_pos > isize)) - iocb->ki_pos = isize; + xfs_rw_iunlock(ip, iolock); + error = filemap_write_and_wait_range(mapping, pos, end); + xfs_rw_ilock(ip, iolock); - if (iocb->ki_pos > ip->i_size) { - xfs_ilock(ip, XFS_ILOCK_EXCL); - if (iocb->ki_pos > ip->i_size) - ip->i_size = iocb->ki_pos; - xfs_iunlock(ip, XFS_ILOCK_EXCL); + error2 = -xfs_file_fsync(file, + (file->f_flags & __O_SYNC) ? 0 : 1); + if (error) + ret = error; + else if (error2) + ret = error2; } - error = -ret; - if (ret <= 0) - goto out_unlock_internal; +out_unlock: + xfs_aio_write_newsize_update(ip); + xfs_rw_iunlock(ip, iolock); + return ret; +} - XFS_STATS_ADD(xs_write_bytes, 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; - /* Handle various SYNC-type writes */ - if ((file->f_flags & O_DSYNC) || IS_SYNC(inode)) { - loff_t end = pos + ret - 1; - int error2; + if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE)) + return -EOPNOTSUPP; - xfs_iunlock(ip, iolock); - if (need_i_mutex) - mutex_unlock(&inode->i_mutex); + bf.l_whence = 0; + bf.l_start = offset; + bf.l_len = len; - error2 = filemap_write_and_wait_range(mapping, pos, end); - if (!error) - error = error2; - if (need_i_mutex) - mutex_lock(&inode->i_mutex); - xfs_ilock(ip, iolock); + xfs_ilock(ip, XFS_IOLOCK_EXCL); - error2 = -xfs_file_fsync(file, - (file->f_flags & __O_SYNC) ? 0 : 1); - if (!error) - error = error2; + 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; } - out_unlock_internal: - if (ip->i_new_size) { - xfs_ilock(ip, XFS_ILOCK_EXCL); - ip->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 (ip->i_d.di_size > ip->i_size) - ip->i_d.di_size = ip->i_size; - xfs_iunlock(ip, XFS_ILOCK_EXCL); + error = -xfs_change_file_space(ip, cmd, &bf, 0, XFS_ATTR_NOLOCK); + 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(ip, &iattr, XFS_ATTR_NOLOCK); } - xfs_iunlock(ip, iolock); - out_unlock_mutex: - if (need_i_mutex) - mutex_unlock(&inode->i_mutex); - return -error; + +out_unlock: + xfs_iunlock(ip, XFS_IOLOCK_EXCL); + return error; } + STATIC int xfs_file_open( struct inode *inode, @@ -921,6 +1055,7 @@ const struct file_operations xfs_file_operations = { .open = xfs_file_open, .release = xfs_file_release, .fsync = xfs_file_fsync, + .fallocate = xfs_file_fallocate, }; const struct file_operations xfs_dir_file_operations = { |