diff options
Diffstat (limited to 'fs/xfs/xfs_iomap.c')
| -rw-r--r-- | fs/xfs/xfs_iomap.c | 171 |
1 files changed, 171 insertions, 0 deletions
diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c index 58391355a44d..620fc9120444 100644 --- a/fs/xfs/xfs_iomap.c +++ b/fs/xfs/xfs_iomap.c @@ -15,6 +15,7 @@ * along with this program; if not, write the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */ +#include <linux/iomap.h> #include "xfs.h" #include "xfs_fs.h" #include "xfs_shared.h" @@ -940,3 +941,173 @@ error_on_bmapi_transaction: xfs_iunlock(ip, XFS_ILOCK_EXCL); return error; } + +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_db(ip, 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); + iomap->bdev = xfs_find_bdev_for_inode(VFS_I(ip)); +} + +static inline bool imap_needs_alloc(struct xfs_bmbt_irec *imap, int nimaps) +{ + return !nimaps || + imap->br_startblock == HOLESTARTBLOCK || + imap->br_startblock == DELAYSTARTBLOCK; +} + +static int +xfs_file_iomap_begin( + struct inode *inode, + loff_t offset, + loff_t length, + unsigned flags, + struct iomap *iomap) +{ + 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; + int nimaps = 1, error = 0; + + if (XFS_FORCED_SHUTDOWN(mp)) + return -EIO; + + xfs_ilock(ip, XFS_ILOCK_EXCL); + + ASSERT(offset <= mp->m_super->s_maxbytes); + if ((xfs_fsize_t)offset + length > mp->m_super->s_maxbytes) + length = mp->m_super->s_maxbytes - offset; + offset_fsb = XFS_B_TO_FSBT(mp, offset); + end_fsb = XFS_B_TO_FSB(mp, offset + length); + + error = xfs_bmapi_read(ip, offset_fsb, end_fsb - offset_fsb, &imap, + &nimaps, XFS_BMAPI_ENTIRE); + if (error) { + xfs_iunlock(ip, XFS_ILOCK_EXCL); + return error; + } + + if ((flags & IOMAP_WRITE) && imap_needs_alloc(&imap, nimaps)) { + /* + * We cap the maximum length we map here to MAX_WRITEBACK_PAGES + * pages to keep the chunks of work done where somewhat symmetric + * with the work writeback does. This is a completely arbitrary + * number pulled out of thin air as a best guess for initial + * testing. + * + * Note that the values needs to be less than 32-bits wide until + * the lower level functions are updated. + */ + length = min_t(loff_t, length, 1024 * PAGE_SIZE); + if (xfs_get_extsz_hint(ip)) { + /* + * xfs_iomap_write_direct() expects the shared lock. It + * is unlocked on return. + */ + xfs_ilock_demote(ip, XFS_ILOCK_EXCL); + error = xfs_iomap_write_direct(ip, offset, length, &imap, + nimaps); + } else { + error = xfs_iomap_write_delay(ip, offset, length, &imap); + xfs_iunlock(ip, XFS_ILOCK_EXCL); + } + + if (error) + return error; + + trace_xfs_iomap_alloc(ip, offset, length, 0, &imap); + xfs_bmbt_to_iomap(ip, iomap, &imap); + } else if (nimaps) { + xfs_iunlock(ip, XFS_ILOCK_EXCL); + trace_xfs_iomap_found(ip, offset, length, 0, &imap); + xfs_bmbt_to_iomap(ip, iomap, &imap); + } else { + xfs_iunlock(ip, XFS_ILOCK_EXCL); + trace_xfs_iomap_not_found(ip, offset, length, 0, &imap); + iomap->blkno = IOMAP_NULL_BLOCK; + iomap->type = IOMAP_HOLE; + iomap->offset = offset; + iomap->length = length; + } + + return 0; +} + +static int +xfs_file_iomap_end_delalloc( + struct xfs_inode *ip, + loff_t offset, + loff_t length, + ssize_t written) +{ + struct xfs_mount *mp = ip->i_mount; + xfs_fileoff_t start_fsb; + xfs_fileoff_t end_fsb; + int error = 0; + + start_fsb = XFS_B_TO_FSB(mp, offset + written); + end_fsb = XFS_B_TO_FSB(mp, offset + length); + + /* + * Trim back delalloc blocks if we didn't manage to write the whole + * range reserved. + * + * We don't need to care about racing delalloc as we hold i_mutex + * across the reserve/allocate/unreserve calls. If there are delalloc + * blocks in the range, they are ours. + */ + if (start_fsb < end_fsb) { + xfs_ilock(ip, XFS_ILOCK_EXCL); + error = xfs_bmap_punch_delalloc_range(ip, start_fsb, + end_fsb - start_fsb); + xfs_iunlock(ip, XFS_ILOCK_EXCL); + + if (error && !XFS_FORCED_SHUTDOWN(mp)) { + xfs_alert(mp, "%s: unable to clean up ino %lld", + __func__, ip->i_ino); + return error; + } + } + + return 0; +} + +static int +xfs_file_iomap_end( + struct inode *inode, + loff_t offset, + loff_t length, + ssize_t written, + unsigned flags, + struct iomap *iomap) +{ + if ((flags & IOMAP_WRITE) && iomap->type == IOMAP_DELALLOC) + return xfs_file_iomap_end_delalloc(XFS_I(inode), offset, + length, written); + return 0; +} + +struct iomap_ops xfs_iomap_ops = { + .iomap_begin = xfs_file_iomap_begin, + .iomap_end = xfs_file_iomap_end, +}; |