| 1 |
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| 2 | #ifndef FS_CEPH_IOCTL_H
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| 3 | #define FS_CEPH_IOCTL_H
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| 4 |
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| 5 | #include <linux/ioctl.h>
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| 6 | #include <linux/types.h>
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| 7 |
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| 8 | #define CEPH_IOCTL_MAGIC 0x97
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| 9 |
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| 10 | |
| 11 | * CEPH_IOC_GET_LAYOUT - get file layout or dir layout policy
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| 12 | * CEPH_IOC_SET_LAYOUT - set file layout
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| 13 | * CEPH_IOC_SET_LAYOUT_POLICY - set dir layout policy
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| 14 | *
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| 15 | * The file layout specifies how file data is striped over objects in
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| 16 | * the distributed object store, which object pool they belong to (if
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| 17 | * it differs from the default), and an optional 'preferred osd' to
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| 18 | * store them on.
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| 19 | *
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| 20 | * Files get a new layout based on the policy set on the containing
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| 21 | * directory or one of its ancestors. The GET_LAYOUT ioctl will let
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| 22 | * you examine the layout for a file or the policy on a directory.
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| 23 | *
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| 24 | * SET_LAYOUT will let you set a layout on a newly created file. This
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| 25 | * only works immediately after the file is created and before any
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| 26 | * data is written to it.
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| 27 | *
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| 28 | * SET_LAYOUT_POLICY will let you set a layout policy (default layout)
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| 29 | * on a directory that will apply to any new files created in that
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| 30 | * directory (or any child directory that doesn't specify a layout of
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| 31 | * its own).
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| 32 |
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| 33 |
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| 34 |
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| 35 | struct ceph_ioctl_layout {
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| 36 | __u64 stripe_unit, stripe_count, object_size;
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| 37 | __u64 data_pool;
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| 38 |
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| 39 |
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| 40 | __s64 preferred_osd;
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| 41 | };
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| 42 |
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| 43 | #define CEPH_IOC_GET_LAYOUT _IOR(CEPH_IOCTL_MAGIC, 1, \
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| 44 | struct ceph_ioctl_layout)
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| 45 | #define CEPH_IOC_SET_LAYOUT _IOW(CEPH_IOCTL_MAGIC, 2, \
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| 46 | struct ceph_ioctl_layout)
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| 47 | #define CEPH_IOC_SET_LAYOUT_POLICY _IOW(CEPH_IOCTL_MAGIC, 5, \
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| 48 | struct ceph_ioctl_layout)
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| 49 |
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| 50 | |
| 51 | * CEPH_IOC_GET_DATALOC - get location of file data in the cluster
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| 52 | *
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| 53 | * Extract identity, address of the OSD and object storing a given
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| 54 | * file offset.
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| 55 |
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| 56 | struct ceph_ioctl_dataloc {
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| 57 | __u64 file_offset;
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| 58 | __u64 object_offset;
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| 59 | __u64 object_no;
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| 60 | __u64 object_size;
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| 61 | char object_name[64];
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| 62 | __u64 block_offset;
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| 63 | __u64 block_size;
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| 64 | __s64 osd;
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| 65 | struct sockaddr_storage osd_addr;
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| 66 | };
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| 67 |
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| 68 | #define CEPH_IOC_GET_DATALOC _IOWR(CEPH_IOCTL_MAGIC, 3, \
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| 69 | struct ceph_ioctl_dataloc)
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| 70 |
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| 71 | |
| 72 | * CEPH_IOC_LAZYIO - relax consistency
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| 73 | *
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| 74 | * Normally Ceph switches to synchronous IO when multiple clients have
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| 75 | * the file open (and or more for write). Reads and writes bypass the
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| 76 | * page cache and go directly to the OSD. Setting this flag on a file
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| 77 | * descriptor will allow buffered IO for this file in cases where the
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| 78 | * application knows it won't interfere with other nodes (or doesn't
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| 79 | * care).
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| 80 |
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| 81 | #define CEPH_IOC_LAZYIO _IO(CEPH_IOCTL_MAGIC, 4)
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| 82 |
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| 83 | |
| 84 | * CEPH_IOC_SYNCIO - force synchronous IO
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| 85 | *
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| 86 | * This ioctl sets a file flag that forces the synchronous IO that
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| 87 | * bypasses the page cache, even if it is not necessary. This is
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| 88 | * essentially the opposite behavior of IOC_LAZYIO. This forces the
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| 89 | * same read/write path as a file opened by multiple clients when one
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| 90 | * or more of those clients is opened for write.
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| 91 | *
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| 92 | * Note that this type of sync IO takes a different path than a file
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| 93 | * opened with O_SYNC/D_SYNC (writes hit the page cache and are
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| 94 | * immediately flushed on page boundaries). It is very similar to
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| 95 | * O_DIRECT (writes bypass the page cache) excep that O_DIRECT writes
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| 96 | * are not copied (user page must remain stable) and O_DIRECT writes
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| 97 | * have alignment restrictions (on the buffer and file offset).
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| 98 |
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| 99 | #define CEPH_IOC_SYNCIO _IO(CEPH_IOCTL_MAGIC, 5)
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| 100 |
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| 101 | #endif
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