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author | Christoph Hellwig <hch@lst.de> | 2015-02-16 11:49:23 +1100 |
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committer | Dave Chinner <david@fromorbit.com> | 2015-02-16 11:49:23 +1100 |
commit | 527851124d10f9c50b1c578e0a56fcd49922422d (patch) | |
tree | f16dd8e452ae24ce6802cfb8c6baa53588de91ab /fs/xfs/xfs_pnfs.c | |
parent | bad962662dbc60e76ec1baae34af56b1ba2dfa5f (diff) | |
download | linux-stable-527851124d10f9c50b1c578e0a56fcd49922422d.tar.gz linux-stable-527851124d10f9c50b1c578e0a56fcd49922422d.tar.bz2 linux-stable-527851124d10f9c50b1c578e0a56fcd49922422d.zip |
xfs: implement pNFS export operations
Add operations to export pNFS block layouts from an XFS filesystem. See
the previous commit adding the operations for an explanation of them.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Diffstat (limited to 'fs/xfs/xfs_pnfs.c')
-rw-r--r-- | fs/xfs/xfs_pnfs.c | 292 |
1 files changed, 292 insertions, 0 deletions
diff --git a/fs/xfs/xfs_pnfs.c b/fs/xfs/xfs_pnfs.c new file mode 100644 index 000000000000..89912b34f184 --- /dev/null +++ b/fs/xfs/xfs_pnfs.c @@ -0,0 +1,292 @@ +/* + * Copyright (c) 2014 Christoph Hellwig. + */ +#include "xfs.h" +#include "xfs_format.h" +#include "xfs_log_format.h" +#include "xfs_trans_resv.h" +#include "xfs_sb.h" +#include "xfs_mount.h" +#include "xfs_inode.h" +#include "xfs_trans.h" +#include "xfs_log.h" +#include "xfs_bmap.h" +#include "xfs_bmap_util.h" +#include "xfs_error.h" +#include "xfs_iomap.h" +#include "xfs_shared.h" +#include "xfs_bit.h" +#include "xfs_pnfs.h" + +/* + * Get a unique ID including its location so that the client can identify + * the exported device. + */ +int +xfs_fs_get_uuid( + struct super_block *sb, + u8 *buf, + u32 *len, + u64 *offset) +{ + struct xfs_mount *mp = XFS_M(sb); + + printk_once(KERN_NOTICE +"XFS (%s): using experimental pNFS feature, use at your own risk!\n", + mp->m_fsname); + + if (*len < sizeof(uuid_t)) + return -EINVAL; + + memcpy(buf, &mp->m_sb.sb_uuid, sizeof(uuid_t)); + *len = sizeof(uuid_t); + *offset = offsetof(struct xfs_dsb, sb_uuid); + return 0; +} + +static void +xfs_bmbt_to_iomap( + struct xfs_inode *ip, + struct iomap *iomap, + struct xfs_bmbt_irec *imap) +{ + struct xfs_mount *mp = ip->i_mount; + + if (imap->br_startblock == HOLESTARTBLOCK) { + iomap->blkno = IOMAP_NULL_BLOCK; + iomap->type = IOMAP_HOLE; + } else if (imap->br_startblock == DELAYSTARTBLOCK) { + iomap->blkno = IOMAP_NULL_BLOCK; + iomap->type = IOMAP_DELALLOC; + } else { + iomap->blkno = + XFS_FSB_TO_DADDR(ip->i_mount, imap->br_startblock); + if (imap->br_state == XFS_EXT_UNWRITTEN) + iomap->type = IOMAP_UNWRITTEN; + else + iomap->type = IOMAP_MAPPED; + } + iomap->offset = XFS_FSB_TO_B(mp, imap->br_startoff); + iomap->length = XFS_FSB_TO_B(mp, imap->br_blockcount); +} + +/* + * Get a layout for the pNFS client. + */ +int +xfs_fs_map_blocks( + struct inode *inode, + loff_t offset, + u64 length, + struct iomap *iomap, + bool write, + u32 *device_generation) +{ + struct xfs_inode *ip = XFS_I(inode); + struct xfs_mount *mp = ip->i_mount; + struct xfs_bmbt_irec imap; + xfs_fileoff_t offset_fsb, end_fsb; + loff_t limit; + int bmapi_flags = XFS_BMAPI_ENTIRE; + int nimaps = 1; + uint lock_flags; + int error = 0; + + if (XFS_FORCED_SHUTDOWN(mp)) + return -EIO; + + /* + * We can't export inodes residing on the realtime device. The realtime + * device doesn't have a UUID to identify it, so the client has no way + * to find it. + */ + if (XFS_IS_REALTIME_INODE(ip)) + return -ENXIO; + + /* + * Lock out any other I/O before we flush and invalidate the pagecache, + * and then hand out a layout to the remote system. This is very + * similar to direct I/O, except that the synchronization is much more + * complicated. See the comment near xfs_break_layouts for a detailed + * explanation. + */ + xfs_ilock(ip, XFS_IOLOCK_EXCL); + + error = -EINVAL; + limit = mp->m_super->s_maxbytes; + if (!write) + limit = max(limit, round_up(i_size_read(inode), + inode->i_sb->s_blocksize)); + if (offset > limit) + goto out_unlock; + if (offset > limit - length) + length = limit - offset; + + error = filemap_write_and_wait(inode->i_mapping); + if (error) + goto out_unlock; + error = invalidate_inode_pages2(inode->i_mapping); + if (WARN_ON_ONCE(error)) + return error; + + end_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)offset + length); + offset_fsb = XFS_B_TO_FSBT(mp, offset); + + lock_flags = xfs_ilock_data_map_shared(ip); + error = xfs_bmapi_read(ip, offset_fsb, end_fsb - offset_fsb, + &imap, &nimaps, bmapi_flags); + xfs_iunlock(ip, lock_flags); + + if (error) + goto out_unlock; + + if (write) { + enum xfs_prealloc_flags flags = 0; + + ASSERT(imap.br_startblock != DELAYSTARTBLOCK); + + if (!nimaps || imap.br_startblock == HOLESTARTBLOCK) { + error = xfs_iomap_write_direct(ip, offset, length, + &imap, nimaps); + if (error) + goto out_unlock; + + /* + * Ensure the next transaction is committed + * synchronously so that the blocks allocated and + * handed out to the client are guaranteed to be + * present even after a server crash. + */ + flags |= XFS_PREALLOC_SET | XFS_PREALLOC_SYNC; + } + + error = xfs_update_prealloc_flags(ip, flags); + if (error) + goto out_unlock; + } + xfs_iunlock(ip, XFS_IOLOCK_EXCL); + + xfs_bmbt_to_iomap(ip, iomap, &imap); + *device_generation = mp->m_generation; + return error; +out_unlock: + xfs_iunlock(ip, XFS_IOLOCK_EXCL); + return error; +} + +/* + * Ensure the size update falls into a valid allocated block. + */ +static int +xfs_pnfs_validate_isize( + struct xfs_inode *ip, + xfs_off_t isize) +{ + struct xfs_bmbt_irec imap; + int nimaps = 1; + int error = 0; + + xfs_ilock(ip, XFS_ILOCK_SHARED); + error = xfs_bmapi_read(ip, XFS_B_TO_FSBT(ip->i_mount, isize - 1), 1, + &imap, &nimaps, 0); + xfs_iunlock(ip, XFS_ILOCK_SHARED); + if (error) + return error; + + if (imap.br_startblock == HOLESTARTBLOCK || + imap.br_startblock == DELAYSTARTBLOCK || + imap.br_state == XFS_EXT_UNWRITTEN) + return -EIO; + return 0; +} + +/* + * Make sure the blocks described by maps are stable on disk. This includes + * converting any unwritten extents, flushing the disk cache and updating the + * time stamps. + * + * Note that we rely on the caller to always send us a timestamp update so that + * we always commit a transaction here. If that stops being true we will have + * to manually flush the cache here similar to what the fsync code path does + * for datasyncs on files that have no dirty metadata. + */ +int +xfs_fs_commit_blocks( + struct inode *inode, + struct iomap *maps, + int nr_maps, + struct iattr *iattr) +{ + struct xfs_inode *ip = XFS_I(inode); + struct xfs_mount *mp = ip->i_mount; + struct xfs_trans *tp; + bool update_isize = false; + int error, i; + loff_t size; + + ASSERT(iattr->ia_valid & (ATTR_ATIME|ATTR_CTIME|ATTR_MTIME)); + + xfs_ilock(ip, XFS_IOLOCK_EXCL); + + size = i_size_read(inode); + if ((iattr->ia_valid & ATTR_SIZE) && iattr->ia_size > size) { + update_isize = true; + size = iattr->ia_size; + } + + for (i = 0; i < nr_maps; i++) { + u64 start, length, end; + + start = maps[i].offset; + if (start > size) + continue; + + end = start + maps[i].length; + if (end > size) + end = size; + + length = end - start; + if (!length) + continue; + + /* + * Make sure reads through the pagecache see the new data. + */ + error = invalidate_inode_pages2_range(inode->i_mapping, + start >> PAGE_CACHE_SHIFT, + (end - 1) >> PAGE_CACHE_SHIFT); + WARN_ON_ONCE(error); + + error = xfs_iomap_write_unwritten(ip, start, length); + if (error) + goto out_drop_iolock; + } + + if (update_isize) { + error = xfs_pnfs_validate_isize(ip, size); + if (error) + goto out_drop_iolock; + } + + tp = xfs_trans_alloc(mp, XFS_TRANS_SETATTR_NOT_SIZE); + error = xfs_trans_reserve(tp, &M_RES(mp)->tr_ichange, 0, 0); + if (error) + goto out_drop_iolock; + + xfs_ilock(ip, XFS_ILOCK_EXCL); + xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL); + xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE); + + xfs_setattr_time(ip, iattr); + if (update_isize) { + i_size_write(inode, iattr->ia_size); + ip->i_d.di_size = iattr->ia_size; + } + + xfs_trans_set_sync(tp); + error = xfs_trans_commit(tp, 0); + +out_drop_iolock: + xfs_iunlock(ip, XFS_IOLOCK_EXCL); + return error; +} |