提交 1de09d1a 编写于 作者: D Dave Chinner 提交者: Ben Myers

xfs: fix incorrect remote symlink block count

When CRCs are enabled, the number of blocks needed to hold a remote
symlink on a 1k block size filesystem may be 2 instead of 1. The
transaction reservation for the allocated blocks was not taking this
into account and only allocating one block. Hence when trying to
read or invalidate such symlinks, we are mapping a hole where there
should be a block and things go bad at that point.

Fix the reservation to use the correct block count, clean up the
block count calculation similar to the remote attribute calculation,
and add a debug guard to detect when we don't write the entire
symlink to disk.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NBen Myers <bpm@sgi.com>
Reviewed-by: NBrian Foster <bfoster@redhat.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

(cherry picked from commit 321a9583)
上级 7d2ffe80
...@@ -56,16 +56,9 @@ xfs_symlink_blocks( ...@@ -56,16 +56,9 @@ xfs_symlink_blocks(
struct xfs_mount *mp, struct xfs_mount *mp,
int pathlen) int pathlen)
{ {
int fsblocks = 0; int buflen = XFS_SYMLINK_BUF_SPACE(mp, mp->m_sb.sb_blocksize);
int len = pathlen;
do { return (pathlen + buflen - 1) / buflen;
fsblocks++;
len -= XFS_SYMLINK_BUF_SPACE(mp, mp->m_sb.sb_blocksize);
} while (len > 0);
ASSERT(fsblocks <= XFS_SYMLINK_MAPS);
return fsblocks;
} }
static int static int
...@@ -405,7 +398,7 @@ xfs_symlink( ...@@ -405,7 +398,7 @@ xfs_symlink(
if (pathlen <= XFS_LITINO(mp, dp->i_d.di_version)) if (pathlen <= XFS_LITINO(mp, dp->i_d.di_version))
fs_blocks = 0; fs_blocks = 0;
else else
fs_blocks = XFS_B_TO_FSB(mp, pathlen); fs_blocks = xfs_symlink_blocks(mp, pathlen);
resblks = XFS_SYMLINK_SPACE_RES(mp, link_name->len, fs_blocks); resblks = XFS_SYMLINK_SPACE_RES(mp, link_name->len, fs_blocks);
error = xfs_trans_reserve(tp, resblks, XFS_SYMLINK_LOG_RES(mp), 0, error = xfs_trans_reserve(tp, resblks, XFS_SYMLINK_LOG_RES(mp), 0,
XFS_TRANS_PERM_LOG_RES, XFS_SYMLINK_LOG_COUNT); XFS_TRANS_PERM_LOG_RES, XFS_SYMLINK_LOG_COUNT);
...@@ -512,7 +505,7 @@ xfs_symlink( ...@@ -512,7 +505,7 @@ xfs_symlink(
cur_chunk = target_path; cur_chunk = target_path;
offset = 0; offset = 0;
for (n = 0; n < nmaps; n++) { for (n = 0; n < nmaps; n++) {
char *buf; char *buf;
d = XFS_FSB_TO_DADDR(mp, mval[n].br_startblock); d = XFS_FSB_TO_DADDR(mp, mval[n].br_startblock);
byte_cnt = XFS_FSB_TO_B(mp, mval[n].br_blockcount); byte_cnt = XFS_FSB_TO_B(mp, mval[n].br_blockcount);
...@@ -525,9 +518,7 @@ xfs_symlink( ...@@ -525,9 +518,7 @@ xfs_symlink(
bp->b_ops = &xfs_symlink_buf_ops; bp->b_ops = &xfs_symlink_buf_ops;
byte_cnt = XFS_SYMLINK_BUF_SPACE(mp, byte_cnt); byte_cnt = XFS_SYMLINK_BUF_SPACE(mp, byte_cnt);
if (pathlen < byte_cnt) { byte_cnt = min(byte_cnt, pathlen);
byte_cnt = pathlen;
}
buf = bp->b_addr; buf = bp->b_addr;
buf += xfs_symlink_hdr_set(mp, ip->i_ino, offset, buf += xfs_symlink_hdr_set(mp, ip->i_ino, offset,
...@@ -542,6 +533,7 @@ xfs_symlink( ...@@ -542,6 +533,7 @@ xfs_symlink(
xfs_trans_log_buf(tp, bp, 0, (buf + byte_cnt - 1) - xfs_trans_log_buf(tp, bp, 0, (buf + byte_cnt - 1) -
(char *)bp->b_addr); (char *)bp->b_addr);
} }
ASSERT(pathlen == 0);
} }
/* /*
......
Markdown is supported
0% .
You are about to add 0 people to the discussion. Proceed with caution.
先完成此消息的编辑!
想要评论请 注册