| Message ID | 20200814080833.84760-9-chandanrlinux@gmail.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Bail out if transaction can cause extent count to overflow | expand |
On Fri, Aug 14, 2020 at 01:38:31PM +0530, Chandan Babu R wrote: > Moving an extent to data fork can cause a sub-interval of an existing > extent to be unmapped. This will increase extent count by 1. Mapping in > the new extent can increase the extent count by 1 again i.e. > | Old extent | New extent | Old extent | > Hence number of extents increases by 2. > > Signed-off-by: Chandan Babu R <chandanrlinux@gmail.com> > --- > fs/xfs/libxfs/xfs_inode_fork.h | 10 +++++++++- > fs/xfs/xfs_reflink.c | 6 ++++++ > 2 files changed, 15 insertions(+), 1 deletion(-) > > diff --git a/fs/xfs/libxfs/xfs_inode_fork.h b/fs/xfs/libxfs/xfs_inode_fork.h > index 63f83a13e0a8..d750bdff17c9 100644 > --- a/fs/xfs/libxfs/xfs_inode_fork.h > +++ b/fs/xfs/libxfs/xfs_inode_fork.h > @@ -76,7 +76,15 @@ struct xfs_ifork { > * increase by 1. > */ > #define XFS_IEXT_INSERT_HOLE_CNT 1 > - > +/* > + * Moving an extent to data fork can cause a sub-interval of an > + * existing extent to be unmapped. This will increase extent count by > + * 1. Mapping in the new extent can increase the extent count by 1 > + * again i.e. > + * | Old extent | New extent | Old extent | This comment is a little oddly formatted, mostly because my brain thought that the line starting with "1. Mapping" was a numbered bullet list. If you reflow the comment further outward, you can get it to look like this: /* * Moving an extent to data fork can cause a sub-interval of an existing * extent to be unmapped, increasing extent count by 1. Mapping in the * new extent can also increase the extent count by 1: * | Old extent | New extent | Old extent | * Hence number of extents increases by 2. */ #define XFS_IEXT_REFLINK_END_COW_CNT 2 --D > + * Hence number of extents increases by 2. > + */ > +#define XFS_IEXT_REFLINK_END_COW_CNT 2 > /* > * Fork handling. > */ > diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c > index aac83f9d6107..04a7754ee681 100644 > --- a/fs/xfs/xfs_reflink.c > +++ b/fs/xfs/xfs_reflink.c > @@ -29,6 +29,7 @@ > #include "xfs_iomap.h" > #include "xfs_sb.h" > #include "xfs_ag_resv.h" > +#include "xfs_trans_resv.h" > > /* > * Copy on Write of Shared Blocks > @@ -628,6 +629,11 @@ xfs_reflink_end_cow_extent( > xfs_ilock(ip, XFS_ILOCK_EXCL); > xfs_trans_ijoin(tp, ip, 0); > > + error = xfs_iext_count_may_overflow(ip, XFS_DATA_FORK, > + XFS_IEXT_REFLINK_END_COW_CNT); > + if (error) > + goto out_cancel; > + > /* > * In case of racing, overlapping AIO writes no COW extents might be > * left by the time I/O completes for the loser of the race. In that > -- > 2.28.0 >
On Wednesday 19 August 2020 3:33:07 AM IST Darrick J. Wong wrote: > On Fri, Aug 14, 2020 at 01:38:31PM +0530, Chandan Babu R wrote: > > Moving an extent to data fork can cause a sub-interval of an existing > > extent to be unmapped. This will increase extent count by 1. Mapping in > > the new extent can increase the extent count by 1 again i.e. > > | Old extent | New extent | Old extent | > > Hence number of extents increases by 2. > > > > Signed-off-by: Chandan Babu R <chandanrlinux@gmail.com> > > --- > > fs/xfs/libxfs/xfs_inode_fork.h | 10 +++++++++- > > fs/xfs/xfs_reflink.c | 6 ++++++ > > 2 files changed, 15 insertions(+), 1 deletion(-) > > > > diff --git a/fs/xfs/libxfs/xfs_inode_fork.h b/fs/xfs/libxfs/xfs_inode_fork.h > > index 63f83a13e0a8..d750bdff17c9 100644 > > --- a/fs/xfs/libxfs/xfs_inode_fork.h > > +++ b/fs/xfs/libxfs/xfs_inode_fork.h > > @@ -76,7 +76,15 @@ struct xfs_ifork { > > * increase by 1. > > */ > > #define XFS_IEXT_INSERT_HOLE_CNT 1 > > - > > +/* > > + * Moving an extent to data fork can cause a sub-interval of an > > + * existing extent to be unmapped. This will increase extent count by > > + * 1. Mapping in the new extent can increase the extent count by 1 > > + * again i.e. > > + * | Old extent | New extent | Old extent | > > This comment is a little oddly formatted, mostly because my brain > thought that the line starting with "1. Mapping" was a numbered bullet > list. If you reflow the comment further outward, you can get it to look > like this: > > /* > * Moving an extent to data fork can cause a sub-interval of an existing > * extent to be unmapped, increasing extent count by 1. Mapping in the > * new extent can also increase the extent count by 1: > * | Old extent | New extent | Old extent | > * Hence number of extents increases by 2. > */ > #define XFS_IEXT_REFLINK_END_COW_CNT 2 > Sure. I will fix up all the comments in the patchset to extend upto 80 columns.
diff --git a/fs/xfs/libxfs/xfs_inode_fork.h b/fs/xfs/libxfs/xfs_inode_fork.h index 63f83a13e0a8..d750bdff17c9 100644 --- a/fs/xfs/libxfs/xfs_inode_fork.h +++ b/fs/xfs/libxfs/xfs_inode_fork.h @@ -76,7 +76,15 @@ struct xfs_ifork { * increase by 1. */ #define XFS_IEXT_INSERT_HOLE_CNT 1 - +/* + * Moving an extent to data fork can cause a sub-interval of an + * existing extent to be unmapped. This will increase extent count by + * 1. Mapping in the new extent can increase the extent count by 1 + * again i.e. + * | Old extent | New extent | Old extent | + * Hence number of extents increases by 2. + */ +#define XFS_IEXT_REFLINK_END_COW_CNT 2 /* * Fork handling. */ diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c index aac83f9d6107..04a7754ee681 100644 --- a/fs/xfs/xfs_reflink.c +++ b/fs/xfs/xfs_reflink.c @@ -29,6 +29,7 @@ #include "xfs_iomap.h" #include "xfs_sb.h" #include "xfs_ag_resv.h" +#include "xfs_trans_resv.h" /* * Copy on Write of Shared Blocks @@ -628,6 +629,11 @@ xfs_reflink_end_cow_extent( xfs_ilock(ip, XFS_ILOCK_EXCL); xfs_trans_ijoin(tp, ip, 0); + error = xfs_iext_count_may_overflow(ip, XFS_DATA_FORK, + XFS_IEXT_REFLINK_END_COW_CNT); + if (error) + goto out_cancel; + /* * In case of racing, overlapping AIO writes no COW extents might be * left by the time I/O completes for the loser of the race. In that
Moving an extent to data fork can cause a sub-interval of an existing extent to be unmapped. This will increase extent count by 1. Mapping in the new extent can increase the extent count by 1 again i.e. | Old extent | New extent | Old extent | Hence number of extents increases by 2. Signed-off-by: Chandan Babu R <chandanrlinux@gmail.com> --- fs/xfs/libxfs/xfs_inode_fork.h | 10 +++++++++- fs/xfs/xfs_reflink.c | 6 ++++++ 2 files changed, 15 insertions(+), 1 deletion(-)