xfs: fix fallocate functions when rtextsize is larger than 1

In commit fe341eb151, I forgot that xfs_free_file_space isn't strictly
a "remove mapped blocks" function.  It is actually a function to zero
file space by punching out the middle and writing zeroes to the
unaligned ends of the specified range.  Therefore, putting a rtextsize
alignment check in that function is wrong because that breaks unaligned
ZERO_RANGE on the realtime volume.

Furthermore, xfs_file_fallocate already has alignment checks for the
functions require the file range to be aligned to the size of a
fundamental allocation unit (which is 1 FSB on the data volume and 1 rt
extent on the realtime volume).  Create a new helper to check fallocate
arguments against the realtiem allocation unit size, fix the fallocate
frontend to use it, fix free_file_space to delete the correct range, and
remove a now redundant check from insert_file_space.

NOTE: The realtime extent size is not required to be a power of two!

Fixes: fe341eb151 ("xfs: ensure that fpunch, fcollapse, and finsert operations are aligned to rt extent size")
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Chandan Babu R <chandanrlinux@gmail.com>
This commit is contained in:
Darrick J. Wong 2020-10-09 16:42:59 -07:00
parent 894645546b
commit 25219dbfa7
3 changed files with 46 additions and 18 deletions

View File

@ -947,11 +947,11 @@ xfs_free_file_space(
endoffset_fsb = XFS_B_TO_FSBT(mp, offset + len);
/* We can only free complete realtime extents. */
if (XFS_IS_REALTIME_INODE(ip)) {
xfs_extlen_t extsz = xfs_get_extsz_hint(ip);
if ((startoffset_fsb | endoffset_fsb) & (extsz - 1))
return -EINVAL;
if (XFS_IS_REALTIME_INODE(ip) && mp->m_sb.sb_rextsize > 1) {
startoffset_fsb = roundup_64(startoffset_fsb,
mp->m_sb.sb_rextsize);
endoffset_fsb = rounddown_64(endoffset_fsb,
mp->m_sb.sb_rextsize);
}
/*
@ -1147,14 +1147,6 @@ xfs_insert_file_space(
trace_xfs_insert_file_space(ip);
/* We can only insert complete realtime extents. */
if (XFS_IS_REALTIME_INODE(ip)) {
xfs_extlen_t extsz = xfs_get_extsz_hint(ip);
if ((stop_fsb | shift_fsb) & (extsz - 1))
return -EINVAL;
}
error = xfs_bmap_can_insert_extents(ip, stop_fsb, shift_fsb);
if (error)
return error;

View File

@ -32,6 +32,39 @@
static const struct vm_operations_struct xfs_file_vm_ops;
/*
* Decide if the given file range is aligned to the size of the fundamental
* allocation unit for the file.
*/
static bool
xfs_is_falloc_aligned(
struct xfs_inode *ip,
loff_t pos,
long long int len)
{
struct xfs_mount *mp = ip->i_mount;
uint64_t mask;
if (XFS_IS_REALTIME_INODE(ip)) {
if (!is_power_of_2(mp->m_sb.sb_rextsize)) {
u64 rextbytes;
u32 mod;
rextbytes = XFS_FSB_TO_B(mp, mp->m_sb.sb_rextsize);
div_u64_rem(pos, rextbytes, &mod);
if (mod)
return false;
div_u64_rem(len, rextbytes, &mod);
return mod == 0;
}
mask = XFS_FSB_TO_B(mp, mp->m_sb.sb_rextsize) - 1;
} else {
mask = mp->m_sb.sb_blocksize - 1;
}
return !((pos | len) & mask);
}
int
xfs_update_prealloc_flags(
struct xfs_inode *ip,
@ -850,9 +883,7 @@ xfs_file_fallocate(
if (error)
goto out_unlock;
} else if (mode & FALLOC_FL_COLLAPSE_RANGE) {
unsigned int blksize_mask = i_blocksize(inode) - 1;
if (offset & blksize_mask || len & blksize_mask) {
if (!xfs_is_falloc_aligned(ip, offset, len)) {
error = -EINVAL;
goto out_unlock;
}
@ -872,10 +903,9 @@ xfs_file_fallocate(
if (error)
goto out_unlock;
} else if (mode & FALLOC_FL_INSERT_RANGE) {
unsigned int blksize_mask = i_blocksize(inode) - 1;
loff_t isize = i_size_read(inode);
if (offset & blksize_mask || len & blksize_mask) {
if (!xfs_is_falloc_aligned(ip, offset, len)) {
error = -EINVAL;
goto out_unlock;
}

View File

@ -175,6 +175,12 @@ static inline xfs_dev_t linux_to_xfs_dev_t(dev_t dev)
#define xfs_sort(a,n,s,fn) sort(a,n,s,fn,NULL)
#define xfs_stack_trace() dump_stack()
static inline uint64_t rounddown_64(uint64_t x, uint32_t y)
{
do_div(x, y);
return x * y;
}
static inline uint64_t roundup_64(uint64_t x, uint32_t y)
{
x += y - 1;