Merge tag 'for-linus-v3.10-rc1' of git://oss.sgi.com/xfs/xfs

Pull xfs update from Ben Myers:
 "For 3.10-rc1 we have a number of bug fixes and cleanups and a
  currently experimental feature from David Chinner, CRCs protection for
  metadata.  CRCs are enabled by using mkfs.xfs to create a filesystem
  with the feature bits set.

   - numerous fixes for speculative preallocation
   - don't verify buffers on IO errors
   - rename of random32 to prandom32
   - refactoring/rearrangement in xfs_bmap.c
   - removal of unused m_inode_shrink in struct xfs_mount
   - fix error handling of xfs_bufs and readahead
   - quota driven preallocation throttling
   - fix WARN_ON in xfs_vm_releasepage
   - add ratelimited printk for different alert levels
   - fix spurious forced shutdowns due to freed Extent Free Intents
   - remove some obsolete XLOG_CIL_HARD_SPACE_LIMIT() macros
   - remove some obsoleted comments
   - (experimental) CRC support for metadata"

* tag 'for-linus-v3.10-rc1' of git://oss.sgi.com/xfs/xfs: (46 commits)
  xfs: fix da node magic number mismatches
  xfs: Remote attr validation fixes and optimisations
  xfs: Teach dquot recovery about CONFIG_XFS_QUOTA
  xfs: add metadata CRC documentation
  xfs: implement extended feature masks
  xfs: add CRC checks to the superblock
  xfs: buffer type overruns blf_flags field
  xfs: add buffer types to directory and attribute buffers
  xfs: add CRC protection to remote attributes
  xfs: split remote attribute code out
  xfs: add CRCs to attr leaf blocks
  xfs: add CRCs to dir2/da node blocks
  xfs: shortform directory offsets change for dir3 format
  xfs: add CRC checking to dir2 leaf blocks
  xfs: add CRC checking to dir2 data blocks
  xfs: add CRC checking to dir2 free blocks
  xfs: add CRC checks to block format directory blocks
  xfs: add CRC checks to remote symlinks
  xfs: split out symlink code into it's own file.
  xfs: add version 3 inode format with CRCs
  ...

Documentation/filesystems/xfs-self-describing-metadata.txt

+XFS Self Describing Metadata
+----------------------------
+
+Introduction
+------------
+
+The largest scalability problem facing XFS is not one of algorithmic
+scalability, but of verification of the filesystem structure. Scalabilty of the
+structures and indexes on disk and the algorithms for iterating them are
+adequate for supporting PB scale filesystems with billions of inodes, however it
+is this very scalability that causes the verification problem.
+
+Almost all metadata on XFS is dynamically allocated. The only fixed location
+metadata is the allocation group headers (SB, AGF, AGFL and AGI), while all
+other metadata structures need to be discovered by walking the filesystem
+structure in different ways. While this is already done by userspace tools for
+validating and repairing the structure, there are limits to what they can
+verify, and this in turn limits the supportable size of an XFS filesystem.
+
+For example, it is entirely possible to manually use xfs_db and a bit of
+scripting to analyse the structure of a 100TB filesystem when trying to
+determine the root cause of a corruption problem, but it is still mainly a
+manual task of verifying that things like single bit errors or misplaced writes
+weren't the ultimate cause of a corruption event. It may take a few hours to a
+few days to perform such forensic analysis, so for at this scale root cause
+analysis is entirely possible.
+
+However, if we scale the filesystem up to 1PB, we now have 10x as much metadata
+to analyse and so that analysis blows out towards weeks/months of forensic work.
+Most of the analysis work is slow and tedious, so as the amount of analysis goes
+up, the more likely that the cause will be lost in the noise.  Hence the primary
+concern for supporting PB scale filesystems is minimising the time and effort
+required for basic forensic analysis of the filesystem structure.
+
+
+Self Describing Metadata
+------------------------
+
+One of the problems with the current metadata format is that apart from the
+magic number in the metadata block, we have no other way of identifying what it
+is supposed to be. We can't even identify if it is the right place. Put simply,
+you can't look at a single metadata block in isolation and say "yes, it is
+supposed to be there and the contents are valid".
+
+Hence most of the time spent on forensic analysis is spent doing basic
+verification of metadata values, looking for values that are in range (and hence
+not detected by automated verification checks) but are not correct. Finding and
+understanding how things like cross linked block lists (e.g. sibling
+pointers in a btree end up with loops in them) are the key to understanding what
+went wrong, but it is impossible to tell what order the blocks were linked into
+each other or written to disk after the fact.
+
+Hence we need to record more information into the metadata to allow us to
+quickly determine if the metadata is intact and can be ignored for the purpose
+of analysis. We can't protect against every possible type of error, but we can
+ensure that common types of errors are easily detectable.  Hence the concept of
+self describing metadata.
+
+The first, fundamental requirement of self describing metadata is that the
+metadata object contains some form of unique identifier in a well known
+location. This allows us to identify the expected contents of the block and
+hence parse and verify the metadata object. IF we can't independently identify
+the type of metadata in the object, then the metadata doesn't describe itself
+very well at all!
+
+Luckily, almost all XFS metadata has magic numbers embedded already - only the
+AGFL, remote symlinks and remote attribute blocks do not contain identifying
+magic numbers. Hence we can change the on-disk format of all these objects to
+add more identifying information and detect this simply by changing the magic
+numbers in the metadata objects. That is, if it has the current magic number,
+the metadata isn't self identifying. If it contains a new magic number, it is
+self identifying and we can do much more expansive automated verification of the
+metadata object at runtime, during forensic analysis or repair.
+
+As a primary concern, self describing metadata needs some form of overall
+integrity checking. We cannot trust the metadata if we cannot verify that it has
+not been changed as a result of external influences. Hence we need some form of
+integrity check, and this is done by adding CRC32c validation to the metadata
+block. If we can verify the block contains the metadata it was intended to
+contain, a large amount of the manual verification work can be skipped.
+
+CRC32c was selected as metadata cannot be more than 64k in length in XFS and
+hence a 32 bit CRC is more than sufficient to detect multi-bit errors in
+metadata blocks. CRC32c is also now hardware accelerated on common CPUs so it is
+fast. So while CRC32c is not the strongest of possible integrity checks that
+could be used, it is more than sufficient for our needs and has relatively
+little overhead. Adding support for larger integrity fields and/or algorithms
+does really provide any extra value over CRC32c, but it does add a lot of
+complexity and so there is no provision for changing the integrity checking
+mechanism.
+
+Self describing metadata needs to contain enough information so that the
+metadata block can be verified as being in the correct place without needing to
+look at any other metadata. This means it needs to contain location information.
+Just adding a block number to the metadata is not sufficient to protect against
+mis-directed writes - a write might be misdirected to the wrong LUN and so be
+written to the "correct block" of the wrong filesystem. Hence location
+information must contain a filesystem identifier as well as a block number.
+
+Another key information point in forensic analysis is knowing who the metadata
+block belongs to. We already know the type, the location, that it is valid
+and/or corrupted, and how long ago that it was last modified. Knowing the owner
+of the block is important as it allows us to find other related metadata to
+determine the scope of the corruption. For example, if we have a extent btree
+object, we don't know what inode it belongs to and hence have to walk the entire
+filesystem to find the owner of the block. Worse, the corruption could mean that
+no owner can be found (i.e. it's an orphan block), and so without an owner field
+in the metadata we have no idea of the scope of the corruption. If we have an
+owner field in the metadata object, we can immediately do top down validation to
+determine the scope of the problem.
+
+Different types of metadata have different owner identifiers. For example,
+directory, attribute and extent tree blocks are all owned by an inode, whilst
+freespace btree blocks are owned by an allocation group. Hence the size and
+contents of the owner field are determined by the type of metadata object we are
+looking at.  The owner information can also identify misplaced writes (e.g.
+freespace btree block written to the wrong AG).
+
+Self describing metadata also needs to contain some indication of when it was
+written to the filesystem. One of the key information points when doing forensic
+analysis is how recently the block was modified. Correlation of set of corrupted
+metadata blocks based on modification times is important as it can indicate
+whether the corruptions are related, whether there's been multiple corruption
+events that lead to the eventual failure, and even whether there are corruptions
+present that the run-time verification is not detecting.
+
+For example, we can determine whether a metadata object is supposed to be free
+space or still allocated if it is still referenced by its owner by looking at
+when the free space btree block that contains the block was last written
+compared to when the metadata object itself was last written.  If the free space
+block is more recent than the object and the object's owner, then there is a
+very good chance that the block should have been removed from the owner.
+
+To provide this "written timestamp", each metadata block gets the Log Sequence
+Number (LSN) of the most recent transaction it was modified on written into it.
+This number will always increase over the life of the filesystem, and the only
+thing that resets it is running xfs_repair on the filesystem. Further, by use of
+the LSN we can tell if the corrupted metadata all belonged to the same log
+checkpoint and hence have some idea of how much modification occurred between
+the first and last instance of corrupt metadata on disk and, further, how much
+modification occurred between the corruption being written and when it was
+detected.
+
+Runtime Validation
+------------------
+
+Validation of self-describing metadata takes place at runtime in two places:
+
+	- immediately after a successful read from disk
+	- immediately prior to write IO submission
+
+The verification is completely stateless - it is done independently of the
+modification process, and seeks only to check that the metadata is what it says
+it is and that the metadata fields are within bounds and internally consistent.
+As such, we cannot catch all types of corruption that can occur within a block
+as there may be certain limitations that operational state enforces of the
+metadata, or there may be corruption of interblock relationships (e.g. corrupted
+sibling pointer lists). Hence we still need stateful checking in the main code
+body, but in general most of the per-field validation is handled by the
+verifiers.
+
+For read verification, the caller needs to specify the expected type of metadata
+that it should see, and the IO completion process verifies that the metadata
+object matches what was expected. If the verification process fails, then it
+marks the object being read as EFSCORRUPTED. The caller needs to catch this
+error (same as for IO errors), and if it needs to take special action due to a
+verification error it can do so by catching the EFSCORRUPTED error value. If we
+need more discrimination of error type at higher levels, we can define new
+error numbers for different errors as necessary.
+
+The first step in read verification is checking the magic number and determining
+whether CRC validating is necessary. If it is, the CRC32c is calculated and
+compared against the value stored in the object itself. Once this is validated,
+further checks are made against the location information, followed by extensive
+object specific metadata validation. If any of these checks fail, then the
+buffer is considered corrupt and the EFSCORRUPTED error is set appropriately.
+
+Write verification is the opposite of the read verification - first the object
+is extensively verified and if it is OK we then update the LSN from the last
+modification made to the object, After this, we calculate the CRC and insert it
+into the object. Once this is done the write IO is allowed to continue. If any
+error occurs during this process, the buffer is again marked with a EFSCORRUPTED
+error for the higher layers to catch.
+
+Structures
+----------
+
+A typical on-disk structure needs to contain the following information:
+
+struct xfs_ondisk_hdr {
+        __be32  magic;		/* magic number */
+        __be32  crc;		/* CRC, not logged */
+        uuid_t  uuid;		/* filesystem identifier */
+        __be64  owner;		/* parent object */
+        __be64  blkno;		/* location on disk */
+        __be64  lsn;		/* last modification in log, not logged */
+};
+
+Depending on the metadata, this information may be part of a header structure
+separate to the metadata contents, or may be distributed through an existing
+structure. The latter occurs with metadata that already contains some of this
+information, such as the superblock and AG headers.
+
+Other metadata may have different formats for the information, but the same
+level of information is generally provided. For example:
+
+	- short btree blocks have a 32 bit owner (ag number) and a 32 bit block
+	  number for location. The two of these combined provide the same
+	  information as @owner and @blkno in eh above structure, but using 8
+	  bytes less space on disk.
+
+	- directory/attribute node blocks have a 16 bit magic number, and the
+	  header that contains the magic number has other information in it as
+	  well. hence the additional metadata headers change the overall format
+	  of the metadata.
+
+A typical buffer read verifier is structured as follows:
+
+#define XFS_FOO_CRC_OFF		offsetof(struct xfs_ondisk_hdr, crc)
+
+static void
+xfs_foo_read_verify(
+	struct xfs_buf	*bp)
+{
+       struct xfs_mount *mp = bp->b_target->bt_mount;
+
+        if ((xfs_sb_version_hascrc(&mp->m_sb) &&
+             !xfs_verify_cksum(bp->b_addr, BBTOB(bp->b_length),
+					XFS_FOO_CRC_OFF)) ||
+            !xfs_foo_verify(bp)) {
+                XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, bp->b_addr);
+                xfs_buf_ioerror(bp, EFSCORRUPTED);
+        }
+}
+
+The code ensures that the CRC is only checked if the filesystem has CRCs enabled
+by checking the superblock of the feature bit, and then if the CRC verifies OK
+(or is not needed) it verifies the actual contents of the block.
+
+The verifier function will take a couple of different forms, depending on
+whether the magic number can be used to determine the format of the block. In
+the case it can't, the code is structured as follows:
+
+static bool
+xfs_foo_verify(
+	struct xfs_buf		*bp)
+{
+        struct xfs_mount	*mp = bp->b_target->bt_mount;
+        struct xfs_ondisk_hdr	*hdr = bp->b_addr;
+
+        if (hdr->magic != cpu_to_be32(XFS_FOO_MAGIC))
+                return false;
+
+        if (!xfs_sb_version_hascrc(&mp->m_sb)) {
+		if (!uuid_equal(&hdr->uuid, &mp->m_sb.sb_uuid))
+			return false;
+		if (bp->b_bn != be64_to_cpu(hdr->blkno))
+			return false;
+		if (hdr->owner == 0)
+			return false;
+	}
+
+	/* object specific verification checks here */
+
+        return true;
+}
+
+If there are different magic numbers for the different formats, the verifier
+will look like:
+
+static bool
+xfs_foo_verify(
+	struct xfs_buf		*bp)
+{
+        struct xfs_mount	*mp = bp->b_target->bt_mount;
+        struct xfs_ondisk_hdr	*hdr = bp->b_addr;
+
+        if (hdr->magic == cpu_to_be32(XFS_FOO_CRC_MAGIC)) {
+		if (!uuid_equal(&hdr->uuid, &mp->m_sb.sb_uuid))
+			return false;
+		if (bp->b_bn != be64_to_cpu(hdr->blkno))
+			return false;
+		if (hdr->owner == 0)
+			return false;
+	} else if (hdr->magic != cpu_to_be32(XFS_FOO_MAGIC))
+		return false;
+
+	/* object specific verification checks here */
+
+        return true;
+}
+
+Write verifiers are very similar to the read verifiers, they just do things in
+the opposite order to the read verifiers. A typical write verifier:
+
+static void
+xfs_foo_write_verify(
+	struct xfs_buf	*bp)
+{
+	struct xfs_mount	*mp = bp->b_target->bt_mount;
+	struct xfs_buf_log_item	*bip = bp->b_fspriv;
+
+	if (!xfs_foo_verify(bp)) {
+		XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, bp->b_addr);
+		xfs_buf_ioerror(bp, EFSCORRUPTED);
+		return;
+	}
+
+	if (!xfs_sb_version_hascrc(&mp->m_sb))
+		return;
+
+
+	if (bip) {
+		struct xfs_ondisk_hdr	*hdr = bp->b_addr;
+		hdr->lsn = cpu_to_be64(bip->bli_item.li_lsn);
+	}
+	xfs_update_cksum(bp->b_addr, BBTOB(bp->b_length), XFS_FOO_CRC_OFF);
+}
+
+This will verify the internal structure of the metadata before we go any
+further, detecting corruptions that have occurred as the metadata has been
+modified in memory. If the metadata verifies OK, and CRCs are enabled, we then
+update the LSN field (when it was last modified) and calculate the CRC on the
+metadata. Once this is done, we can issue the IO.
+
+Inodes and Dquots
+-----------------
+
+Inodes and dquots are special snowflakes. They have per-object CRC and
+self-identifiers, but they are packed so that there are multiple objects per
+buffer. Hence we do not use per-buffer verifiers to do the work of per-object
+verification and CRC calculations. The per-buffer verifiers simply perform basic
+identification of the buffer - that they contain inodes or dquots, and that
+there are magic numbers in all the expected spots. All further CRC and
+verification checks are done when each inode is read from or written back to the
+buffer.
+
+The structure of the verifiers and the identifiers checks is very similar to the
+buffer code described above. The only difference is where they are called. For
+example, inode read verification is done in xfs_iread() when the inode is first
+read out of the buffer and the struct xfs_inode is instantiated. The inode is
+already extensively verified during writeback in xfs_iflush_int, so the only
+addition here is to add the LSN and CRC to the inode as it is copied back into
+the buffer.
+
+XXX: inode unlinked list modification doesn't recalculate the inode CRC! None of
+the unlinked list modifications check or update CRCs, neither during unlink nor
+log recovery. So, it's gone unnoticed until now. This won't matter immediately -
+repair will probably complain about it - but it needs to be fixed.
+

fs/xfs/Makefile

@@ -45,11 +45,11 @@ xfs-y				+= xfs_aops.o \
 				   xfs_itable.o \
 				   xfs_message.o \
 				   xfs_mru_cache.o \
-				   xfs_super.o \
-				   xfs_xattr.o \
 				   xfs_rename.o \
+				   xfs_super.o \
 				   xfs_utils.o \
 				   xfs_vnodeops.o \
+				   xfs_xattr.o \
 				   kmem.o \
 				   uuid.o
 
@@ -58,6 +58,7 @@ xfs-y				+= xfs_alloc.o \
 				   xfs_alloc_btree.o \
 				   xfs_attr.o \
 				   xfs_attr_leaf.o \
+				   xfs_attr_remote.o \
 				   xfs_bmap.o \
 				   xfs_bmap_btree.o \
 				   xfs_btree.o \
@@ -73,6 +74,7 @@ xfs-y				+= xfs_alloc.o \
 				   xfs_inode.o \
 				   xfs_log_recover.o \
 				   xfs_mount.o \
+				   xfs_symlink.o \
 				   xfs_trans.o
 
 # low-level transaction/log code

fs/xfs/xfs_ag.h

@@ -30,6 +30,7 @@ struct xfs_trans;
 
 #define	XFS_AGF_MAGIC	0x58414746	/* 'XAGF' */
 #define	XFS_AGI_MAGIC	0x58414749	/* 'XAGI' */
+#define	XFS_AGFL_MAGIC	0x5841464c	/* 'XAFL' */
 #define	XFS_AGF_VERSION	1
 #define	XFS_AGI_VERSION	1
 
@@ -63,12 +64,29 @@ typedef struct xfs_agf {
 	__be32		agf_spare0;	/* spare field */
 	__be32		agf_levels[XFS_BTNUM_AGF];	/* btree levels */
 	__be32		agf_spare1;	/* spare field */
+
 	__be32		agf_flfirst;	/* first freelist block's index */
 	__be32		agf_fllast;	/* last freelist block's index */
 	__be32		agf_flcount;	/* count of blocks in freelist */
 	__be32		agf_freeblks;	/* total free blocks */
+
 	__be32		agf_longest;	/* longest free space */
 	__be32		agf_btreeblks;	/* # of blocks held in AGF btrees */
+	uuid_t		agf_uuid;	/* uuid of filesystem */
+
+	/*
+	 * reserve some contiguous space for future logged fields before we add
+	 * the unlogged fields. This makes the range logging via flags and
+	 * structure offsets much simpler.
+	 */
+	__be64		agf_spare64[16];
+
+	/* unlogged fields, written during buffer writeback. */
+	__be64		agf_lsn;	/* last write sequence */
+	__be32		agf_crc;	/* crc of agf sector */
+	__be32		agf_spare2;
+
+	/* structure must be padded to 64 bit alignment */
 } xfs_agf_t;
 
 #define	XFS_AGF_MAGICNUM	0x00000001
@@ -83,7 +101,8 @@ typedef struct xfs_agf {
 #define	XFS_AGF_FREEBLKS	0x00000200
 #define	XFS_AGF_LONGEST		0x00000400
 #define	XFS_AGF_BTREEBLKS	0x00000800
-#define	XFS_AGF_NUM_BITS	12
+#define	XFS_AGF_UUID		0x00001000
+#define	XFS_AGF_NUM_BITS	13
 #define	XFS_AGF_ALL_BITS	((1 << XFS_AGF_NUM_BITS) - 1)
 
 #define XFS_AGF_FLAGS \
@@ -98,7 +117,8 @@ typedef struct xfs_agf {
 	{ XFS_AGF_FLCOUNT,	"FLCOUNT" }, \
 	{ XFS_AGF_FREEBLKS,	"FREEBLKS" }, \
 	{ XFS_AGF_LONGEST,	"LONGEST" }, \
-	{ XFS_AGF_BTREEBLKS,	"BTREEBLKS" }
+	{ XFS_AGF_BTREEBLKS,	"BTREEBLKS" }, \
+	{ XFS_AGF_UUID,		"UUID" }
 
 /* disk block (xfs_daddr_t) in the AG */
 #define XFS_AGF_DADDR(mp)	((xfs_daddr_t)(1 << (mp)->m_sectbb_log))
@@ -132,6 +152,7 @@ typedef struct xfs_agi {
 	__be32		agi_root;	/* root of inode btree */
 	__be32		agi_level;	/* levels in inode btree */
 	__be32		agi_freecount;	/* number of free inodes */
+
 	__be32		agi_newino;	/* new inode just allocated */
 	__be32		agi_dirino;	/* last directory inode chunk */
 	/*
@@ -139,6 +160,13 @@ typedef struct xfs_agi {
 	 * still being referenced.
 	 */
 	__be32		agi_unlinked[XFS_AGI_UNLINKED_BUCKETS];
+
+	uuid_t		agi_uuid;	/* uuid of filesystem */
+	__be32		agi_crc;	/* crc of agi sector */
+	__be32		agi_pad32;
+	__be64		agi_lsn;	/* last write sequence */
+
+	/* structure must be padded to 64 bit alignment */
 } xfs_agi_t;
 
 #define	XFS_AGI_MAGICNUM	0x00000001
@@ -171,11 +199,31 @@ extern const struct xfs_buf_ops xfs_agi_buf_ops;
  */
 #define XFS_AGFL_DADDR(mp)	((xfs_daddr_t)(3 << (mp)->m_sectbb_log))
 #define	XFS_AGFL_BLOCK(mp)	XFS_HDR_BLOCK(mp, XFS_AGFL_DADDR(mp))
-#define XFS_AGFL_SIZE(mp)	((mp)->m_sb.sb_sectsize / sizeof(xfs_agblock_t))
 #define	XFS_BUF_TO_AGFL(bp)	((xfs_agfl_t *)((bp)->b_addr))
 
+#define XFS_BUF_TO_AGFL_BNO(mp, bp) \
+	(xfs_sb_version_hascrc(&((mp)->m_sb)) ? \
+		&(XFS_BUF_TO_AGFL(bp)->agfl_bno[0]) : \
+		(__be32 *)(bp)->b_addr)
+
+/*
+ * Size of the AGFL.  For CRC-enabled filesystes we steal a couple of
+ * slots in the beginning of the block for a proper header with the
+ * location information and CRC.
+ */
+#define XFS_AGFL_SIZE(mp) \
+	(((mp)->m_sb.sb_sectsize - \
+	 (xfs_sb_version_hascrc(&((mp)->m_sb)) ? \
+		sizeof(struct xfs_agfl) : 0)) / \
+	  sizeof(xfs_agblock_t))
+
 typedef struct xfs_agfl {
-	__be32		agfl_bno[1];	/* actually XFS_AGFL_SIZE(mp) */
+	__be32		agfl_magicnum;
+	__be32		agfl_seqno;
+	uuid_t		agfl_uuid;
+	__be64		agfl_lsn;
+	__be32		agfl_crc;
+	__be32		agfl_bno[];	/* actually XFS_AGFL_SIZE(mp) */
 } xfs_agfl_t;
 
 /*

fs/xfs/xfs_alloc.c

@@ -33,7 +33,9 @@
 #include "xfs_alloc.h"
 #include "xfs_extent_busy.h"
 #include "xfs_error.h"
+#include "xfs_cksum.h"
 #include "xfs_trace.h"
+#include "xfs_buf_item.h"
 
 struct workqueue_struct *xfs_alloc_wq;
 
@@ -430,53 +432,84 @@ xfs_alloc_fixup_trees(
 	return 0;
 }
 
-static void
+static bool
 xfs_agfl_verify(
 	struct xfs_buf	*bp)
 {
-#ifdef WHEN_CRCS_COME_ALONG
-	/*
-	 * we cannot actually do any verification of the AGFL because mkfs does
-	 * not initialise the AGFL to zero or NULL. Hence the only valid part of
-	 * the AGFL is what the AGF says is active. We can't get to the AGF, so
-	 * we can't verify just those entries are valid.
-	 *
-	 * This problem goes away when the CRC format change comes along as that
-	 * requires the AGFL to be initialised by mkfs. At that point, we can
-	 * verify the blocks in the agfl -active or not- lie within the bounds
-	 * of the AG. Until then, just leave this check ifdef'd out.
-	 */
 	struct xfs_mount *mp = bp->b_target->bt_mount;
 	struct xfs_agfl	*agfl = XFS_BUF_TO_AGFL(bp);
-	int		agfl_ok = 1;
-
 	int		i;
 
+	if (!uuid_equal(&agfl->agfl_uuid, &mp->m_sb.sb_uuid))
+		return false;
+	if (be32_to_cpu(agfl->agfl_magicnum) != XFS_AGFL_MAGIC)
+		return false;
+	/*
+	 * during growfs operations, the perag is not fully initialised,
+	 * so we can't use it for any useful checking. growfs ensures we can't
+	 * use it by using uncached buffers that don't have the perag attached
+	 * so we can detect and avoid this problem.
+	 */
+	if (bp->b_pag && be32_to_cpu(agfl->agfl_seqno) != bp->b_pag->pag_agno)
+		return false;
+
 	for (i = 0; i < XFS_AGFL_SIZE(mp); i++) {
-		if (be32_to_cpu(agfl->agfl_bno[i]) == NULLAGBLOCK ||
+		if (be32_to_cpu(agfl->agfl_bno[i]) != NULLAGBLOCK &&
 		    be32_to_cpu(agfl->agfl_bno[i]) >= mp->m_sb.sb_agblocks)
-			agfl_ok = 0;
+			return false;
 	}
+	return true;
+}
+
+static void
+xfs_agfl_read_verify(
+	struct xfs_buf	*bp)
+{
+	struct xfs_mount *mp = bp->b_target->bt_mount;
+	int		agfl_ok = 1;
+
+	/*
+	 * There is no verification of non-crc AGFLs because mkfs does not
+	 * initialise the AGFL to zero or NULL. Hence the only valid part of the
+	 * AGFL is what the AGF says is active. We can't get to the AGF, so we
+	 * can't verify just those entries are valid.
+	 */
+	if (!xfs_sb_version_hascrc(&mp->m_sb))
+		return;
+
+	agfl_ok = xfs_verify_cksum(bp->b_addr, BBTOB(bp->b_length),
+				   offsetof(struct xfs_agfl, agfl_crc));
+
+	agfl_ok = agfl_ok && xfs_agfl_verify(bp);
 
 	if (!agfl_ok) {
-		XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, agfl);
+		XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, bp->b_addr);
 		xfs_buf_ioerror(bp, EFSCORRUPTED);
 	}
-#endif
 }
 
 static void
 xfs_agfl_write_verify(
 	struct xfs_buf	*bp)
 {
-	xfs_agfl_verify(bp);
-}
+	struct xfs_mount *mp = bp->b_target->bt_mount;
+	struct xfs_buf_log_item	*bip = bp->b_fspriv;
 
-static void
-xfs_agfl_read_verify(
-	struct xfs_buf	*bp)
-{
-	xfs_agfl_verify(bp);
+	/* no verification of non-crc AGFLs */
+	if (!xfs_sb_version_hascrc(&mp->m_sb))
+		return;
+
+	if (!xfs_agfl_verify(bp)) {
+		XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, bp->b_addr);
+		xfs_buf_ioerror(bp, EFSCORRUPTED);
+		return;
+	}
+
+	if (bip)
+		XFS_BUF_TO_AGFL(bp)->agfl_lsn = cpu_to_be64(bip->bli_item.li_lsn);
+
+	xfs_update_cksum(bp->b_addr, BBTOB(bp->b_length),
+			 offsetof(struct xfs_agfl, agfl_crc));
 }
 
 const struct xfs_buf_ops xfs_agfl_buf_ops = {
@@ -842,7 +875,7 @@ xfs_alloc_ag_vextent_near(
 	 */
 	int		dofirst;	/* set to do first algorithm */
 
-	dofirst = random32() & 1;
+	dofirst = prandom_u32() & 1;
 #endif
 
 restart:
@@ -1982,18 +2015,18 @@ xfs_alloc_get_freelist(
 	int		btreeblk) /* destination is a AGF btree */
 {
 	xfs_agf_t	*agf;	/* a.g. freespace structure */
-	xfs_agfl_t	*agfl;	/* a.g. freelist structure */
 	xfs_buf_t	*agflbp;/* buffer for a.g. freelist structure */
 	xfs_agblock_t	bno;	/* block number returned */
+	__be32		*agfl_bno;
 	int		error;
 	int		logflags;
-	xfs_mount_t	*mp;	/* mount structure */
+	xfs_mount_t	*mp = tp->t_mountp;
 	xfs_perag_t	*pag;	/* per allocation group data */
 
-	agf = XFS_BUF_TO_AGF(agbp);
 	/*
 	 * Freelist is empty, give up.
 	 */
+	agf = XFS_BUF_TO_AGF(agbp);
 	if (!agf->agf_flcount) {
 		*bnop = NULLAGBLOCK;
 		return 0;
@@ -2001,15 +2034,17 @@ xfs_alloc_get_freelist(
 	/*
 	 * Read the array of free blocks.
 	 */
-	mp = tp->t_mountp;
-	if ((error = xfs_alloc_read_agfl(mp, tp,
-			be32_to_cpu(agf->agf_seqno), &agflbp)))
+	error = xfs_alloc_read_agfl(mp, tp, be32_to_cpu(agf->agf_seqno),
+				    &agflbp);
+	if (error)
 		return error;
-	agfl = XFS_BUF_TO_AGFL(agflbp);
+
+
 	/*
 	 * Get the block number and update the data structures.
 	 */
-	bno = be32_to_cpu(agfl->agfl_bno[be32_to_cpu(agf->agf_flfirst)]);
+	agfl_bno = XFS_BUF_TO_AGFL_BNO(mp, agflbp);
+	bno = be32_to_cpu(agfl_bno[be32_to_cpu(agf->agf_flfirst)]);
 	be32_add_cpu(&agf->agf_flfirst, 1);
 	xfs_trans_brelse(tp, agflbp);
 	if (be32_to_cpu(agf->agf_flfirst) == XFS_AGFL_SIZE(mp))
@@ -2058,11 +2093,14 @@ xfs_alloc_log_agf(
 		offsetof(xfs_agf_t, agf_freeblks),
 		offsetof(xfs_agf_t, agf_longest),
 		offsetof(xfs_agf_t, agf_btreeblks),
+		offsetof(xfs_agf_t, agf_uuid),
 		sizeof(xfs_agf_t)
 	};
 
 	trace_xfs_agf(tp->t_mountp, XFS_BUF_TO_AGF(bp), fields, _RET_IP_);
 
+	xfs_trans_buf_set_type(tp, bp, XFS_BLFT_AGF_BUF);
+
 	xfs_btree_offsets(fields, offsets, XFS_AGF_NUM_BITS, &first, &last);
 	xfs_trans_log_buf(tp, bp, (uint)first, (uint)last);
 }
@@ -2099,12 +2137,13 @@ xfs_alloc_put_freelist(
 	int			btreeblk) /* block came from a AGF btree */
 {
 	xfs_agf_t		*agf;	/* a.g. freespace structure */
-	xfs_agfl_t		*agfl;	/* a.g. free block array */
 	__be32			*blockp;/* pointer to array entry */
 	int			error;
 	int			logflags;
 	xfs_mount_t		*mp;	/* mount structure */
 	xfs_perag_t		*pag;	/* per allocation group data */
+	__be32			*agfl_bno;
+	int			startoff;
 
 	agf = XFS_BUF_TO_AGF(agbp);
 	mp = tp->t_mountp;
@@ -2112,7 +2151,6 @@ xfs_alloc_put_freelist(
 	if (!agflbp && (error = xfs_alloc_read_agfl(mp, tp,
 			be32_to_cpu(agf->agf_seqno), &agflbp)))
 		return error;
-	agfl = XFS_BUF_TO_AGFL(agflbp);
 	be32_add_cpu(&agf->agf_fllast, 1);
 	if (be32_to_cpu(agf->agf_fllast) == XFS_AGFL_SIZE(mp))
 		agf->agf_fllast = 0;
@@ -2133,32 +2171,38 @@ xfs_alloc_put_freelist(
 	xfs_alloc_log_agf(tp, agbp, logflags);
 
 	ASSERT(be32_to_cpu(agf->agf_flcount) <= XFS_AGFL_SIZE(mp));
-	blockp = &agfl->agfl_bno[be32_to_cpu(agf->agf_fllast)];
+
+	agfl_bno = XFS_BUF_TO_AGFL_BNO(mp, agflbp);
+	blockp = &agfl_bno[be32_to_cpu(agf->agf_fllast)];
 	*blockp = cpu_to_be32(bno);
+	startoff = (char *)blockp - (char *)agflbp->b_addr;
+
 	xfs_alloc_log_agf(tp, agbp, logflags);
-	xfs_trans_log_buf(tp, agflbp,
-		(int)((xfs_caddr_t)blockp - (xfs_caddr_t)agfl),
-		(int)((xfs_caddr_t)blockp - (xfs_caddr_t)agfl +
-			sizeof(xfs_agblock_t) - 1));
+
+	xfs_trans_buf_set_type(tp, agflbp, XFS_BLFT_AGFL_BUF);
+	xfs_trans_log_buf(tp, agflbp, startoff,
+			  startoff + sizeof(xfs_agblock_t) - 1);
 	return 0;
 }
 
-static void
+static bool
 xfs_agf_verify(
+	struct xfs_mount *mp,
 	struct xfs_buf	*bp)
  {
-	struct xfs_mount *mp = bp->b_target->bt_mount;
-	struct xfs_agf	*agf;
-	int		agf_ok;
+	struct xfs_agf	*agf = XFS_BUF_TO_AGF(bp);
 
-	agf = XFS_BUF_TO_AGF(bp);
+	if (xfs_sb_version_hascrc(&mp->m_sb) &&
+	    !uuid_equal(&agf->agf_uuid, &mp->m_sb.sb_uuid))
+			return false;
 
-	agf_ok = agf->agf_magicnum == cpu_to_be32(XFS_AGF_MAGIC) &&
-		XFS_AGF_GOOD_VERSION(be32_to_cpu(agf->agf_versionnum)) &&
-		be32_to_cpu(agf->agf_freeblks) <= be32_to_cpu(agf->agf_length) &&
-		be32_to_cpu(agf->agf_flfirst) < XFS_AGFL_SIZE(mp) &&
-		be32_to_cpu(agf->agf_fllast) < XFS_AGFL_SIZE(mp) &&
-		be32_to_cpu(agf->agf_flcount) <= XFS_AGFL_SIZE(mp);
+	if (!(agf->agf_magicnum == cpu_to_be32(XFS_AGF_MAGIC) &&
+	      XFS_AGF_GOOD_VERSION(be32_to_cpu(agf->agf_versionnum)) &&
+	      be32_to_cpu(agf->agf_freeblks) <= be32_to_cpu(agf->agf_length) &&
+	      be32_to_cpu(agf->agf_flfirst) < XFS_AGFL_SIZE(mp) &&
+	      be32_to_cpu(agf->agf_fllast) < XFS_AGFL_SIZE(mp) &&
+	      be32_to_cpu(agf->agf_flcount) <= XFS_AGFL_SIZE(mp)))
+		return false;
 
 	/*
 	 * during growfs operations, the perag is not fully initialised,
@@ -2166,33 +2210,58 @@ xfs_agf_verify(
 	 * use it by using uncached buffers that don't have the perag attached
 	 * so we can detect and avoid this problem.
 	 */
-	if (bp->b_pag)
-		agf_ok = agf_ok && be32_to_cpu(agf->agf_seqno) ==
-						bp->b_pag->pag_agno;
+	if (bp->b_pag && be32_to_cpu(agf->agf_seqno) != bp->b_pag->pag_agno)
+		return false;
 
-	if (xfs_sb_version_haslazysbcount(&mp->m_sb))
-		agf_ok = agf_ok && be32_to_cpu(agf->agf_btreeblks) <=
-						be32_to_cpu(agf->agf_length);
+	if (xfs_sb_version_haslazysbcount(&mp->m_sb) &&
+	    be32_to_cpu(agf->agf_btreeblks) > be32_to_cpu(agf->agf_length))
+		return false;
+
+	return true;;
 
-	if (unlikely(XFS_TEST_ERROR(!agf_ok, mp, XFS_ERRTAG_ALLOC_READ_AGF,
-			XFS_RANDOM_ALLOC_READ_AGF))) {
-		XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, agf);
-		xfs_buf_ioerror(bp, EFSCORRUPTED);
-	}
 }
 
 static void
 xfs_agf_read_verify(
 	struct xfs_buf	*bp)
 {
-	xfs_agf_verify(bp);
+	struct xfs_mount *mp = bp->b_target->bt_mount;
+	int		agf_ok = 1;
+
+	if (xfs_sb_version_hascrc(&mp->m_sb))
+		agf_ok = xfs_verify_cksum(bp->b_addr, BBTOB(bp->b_length),
+					  offsetof(struct xfs_agf, agf_crc));
+
+	agf_ok = agf_ok && xfs_agf_verify(mp, bp);
+
+	if (unlikely(XFS_TEST_ERROR(!agf_ok, mp, XFS_ERRTAG_ALLOC_READ_AGF,
+			XFS_RANDOM_ALLOC_READ_AGF))) {
+		XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, bp->b_addr);
+		xfs_buf_ioerror(bp, EFSCORRUPTED);
+	}
 }
 
 static void
 xfs_agf_write_verify(
 	struct xfs_buf	*bp)
 {
-	xfs_agf_verify(bp);
+	struct xfs_mount *mp = bp->b_target->bt_mount;
+	struct xfs_buf_log_item	*bip = bp->b_fspriv;
+
+	if (!xfs_agf_verify(mp, bp)) {
+		XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, bp->b_addr);
+		xfs_buf_ioerror(bp, EFSCORRUPTED);
+		return;
+	}
+
+	if (!xfs_sb_version_hascrc(&mp->m_sb))
+		return;
+
+	if (bip)
+		XFS_BUF_TO_AGF(bp)->agf_lsn = cpu_to_be64(bip->bli_item.li_lsn);
+
+	xfs_update_cksum(bp->b_addr, BBTOB(bp->b_length),
+			 offsetof(struct xfs_agf, agf_crc));
 }
 
 const struct xfs_buf_ops xfs_agf_buf_ops = {

fs/xfs/xfs_alloc_btree.c

@@ -33,6 +33,7 @@
 #include "xfs_extent_busy.h"
 #include "xfs_error.h"
 #include "xfs_trace.h"
+#include "xfs_cksum.h"
 
 
 STATIC struct xfs_btree_cur *
@@ -272,7 +273,7 @@ xfs_allocbt_key_diff(
 	return (__int64_t)be32_to_cpu(kp->ar_startblock) - rec->ar_startblock;
 }
 
-static void
+static bool
 xfs_allocbt_verify(
 	struct xfs_buf		*bp)
 {
@@ -280,66 +281,103 @@ xfs_allocbt_verify(
 	struct xfs_btree_block	*block = XFS_BUF_TO_BLOCK(bp);
 	struct xfs_perag	*pag = bp->b_pag;
 	unsigned int		level;
-	int			sblock_ok; /* block passes checks */
 
 	/*
 	 * magic number and level verification
 	 *
-	 * During growfs operations, we can't verify the exact level as the
-	 * perag is not fully initialised and hence not attached to the buffer.
-	 * In this case, check against the maximum tree depth.
+	 * During growfs operations, we can't verify the exact level or owner as
+	 * the perag is not fully initialised and hence not attached to the
+	 * buffer.  In this case, check against the maximum tree depth.
+	 *
+	 * Similarly, during log recovery we will have a perag structure
+	 * attached, but the agf information will not yet have been initialised
+	 * from the on disk AGF. Again, we can only check against maximum limits
+	 * in this case.
 	 */
 	level = be16_to_cpu(block->bb_level);
 	switch (block->bb_magic) {
+	case cpu_to_be32(XFS_ABTB_CRC_MAGIC):
+		if (!xfs_sb_version_hascrc(&mp->m_sb))
+			return false;
+		if (!uuid_equal(&block->bb_u.s.bb_uuid, &mp->m_sb.sb_uuid))
+			return false;
+		if (block->bb_u.s.bb_blkno != cpu_to_be64(bp->b_bn))
+			return false;
+		if (pag &&
+		    be32_to_cpu(block->bb_u.s.bb_owner) != pag->pag_agno)
+			return false;
+		/* fall through */
 	case cpu_to_be32(XFS_ABTB_MAGIC):
-		if (pag)
-			sblock_ok = level < pag->pagf_levels[XFS_BTNUM_BNOi];
-		else
-			sblock_ok = level < mp->m_ag_maxlevels;
+		if (pag && pag->pagf_init) {
+			if (level >= pag->pagf_levels[XFS_BTNUM_BNOi])
+				return false;
+		} else if (level >= mp->m_ag_maxlevels)
+			return false;
 		break;
+	case cpu_to_be32(XFS_ABTC_CRC_MAGIC):
+		if (!xfs_sb_version_hascrc(&mp->m_sb))
+			return false;
+		if (!uuid_equal(&block->bb_u.s.bb_uuid, &mp->m_sb.sb_uuid))
+			return false;
+		if (block->bb_u.s.bb_blkno != cpu_to_be64(bp->b_bn))
+			return false;
+		if (pag &&
+		    be32_to_cpu(block->bb_u.s.bb_owner) != pag->pag_agno)
+			return false;
+		/* fall through */
 	case cpu_to_be32(XFS_ABTC_MAGIC):
-		if (pag)
-			sblock_ok = level < pag->pagf_levels[XFS_BTNUM_CNTi];
-		else
-			sblock_ok = level < mp->m_ag_maxlevels;
+		if (pag && pag->pagf_init) {
+			if (level >= pag->pagf_levels[XFS_BTNUM_CNTi])
+				return false;
+		} else if (level >= mp->m_ag_maxlevels)
+			return false;
 		break;
 	default:
-		sblock_ok = 0;
-		break;
+		return false;
 	}
 
 	/* numrecs verification */
-	sblock_ok = sblock_ok &&
-		be16_to_cpu(block->bb_numrecs) <= mp->m_alloc_mxr[level != 0];
+	if (be16_to_cpu(block->bb_numrecs) > mp->m_alloc_mxr[level != 0])
+		return false;
 
 	/* sibling pointer verification */
-	sblock_ok = sblock_ok &&
-		(block->bb_u.s.bb_leftsib == cpu_to_be32(NULLAGBLOCK) ||
-		 be32_to_cpu(block->bb_u.s.bb_leftsib) < mp->m_sb.sb_agblocks) &&
-		block->bb_u.s.bb_leftsib &&
-		(block->bb_u.s.bb_rightsib == cpu_to_be32(NULLAGBLOCK) ||
-		 be32_to_cpu(block->bb_u.s.bb_rightsib) < mp->m_sb.sb_agblocks) &&
-		block->bb_u.s.bb_rightsib;
-
-	if (!sblock_ok) {
-		trace_xfs_btree_corrupt(bp, _RET_IP_);
-		XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, block);
-		xfs_buf_ioerror(bp, EFSCORRUPTED);
-	}
+	if (!block->bb_u.s.bb_leftsib ||
+	    (be32_to_cpu(block->bb_u.s.bb_leftsib) >= mp->m_sb.sb_agblocks &&
+	     block->bb_u.s.bb_leftsib != cpu_to_be32(NULLAGBLOCK)))
+		return false;
+	if (!block->bb_u.s.bb_rightsib ||
+	    (be32_to_cpu(block->bb_u.s.bb_rightsib) >= mp->m_sb.sb_agblocks &&
+	     block->bb_u.s.bb_rightsib != cpu_to_be32(NULLAGBLOCK)))
+		return false;
+
+	return true;
 }
 
 static void
 xfs_allocbt_read_verify(
 	struct xfs_buf	*bp)
 {
-	xfs_allocbt_verify(bp);
+	if (!(xfs_btree_sblock_verify_crc(bp) &&
+	      xfs_allocbt_verify(bp))) {
+		trace_xfs_btree_corrupt(bp, _RET_IP_);
+		XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW,
+				     bp->b_target->bt_mount, bp->b_addr);
+		xfs_buf_ioerror(bp, EFSCORRUPTED);
+	}
 }
 
 static void
 xfs_allocbt_write_verify(
 	struct xfs_buf	*bp)
 {
-	xfs_allocbt_verify(bp);
+	if (!xfs_allocbt_verify(bp)) {
+		trace_xfs_btree_corrupt(bp, _RET_IP_);
+		XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW,
+				     bp->b_target->bt_mount, bp->b_addr);
+		xfs_buf_ioerror(bp, EFSCORRUPTED);
+	}
+	xfs_btree_sblock_calc_crc(bp);
+
 }
 
 const struct xfs_buf_ops xfs_allocbt_buf_ops = {
@@ -444,6 +482,9 @@ xfs_allocbt_init_cursor(
 	cur->bc_private.a.agbp = agbp;
 	cur->bc_private.a.agno = agno;
 
+	if (xfs_sb_version_hascrc(&mp->m_sb))
+		cur->bc_flags |= XFS_BTREE_CRC_BLOCKS;
+
 	return cur;
 }
 

fs/xfs/xfs_alloc_btree.h

@@ -31,8 +31,10 @@ struct xfs_mount;
  * by blockcount and blockno.  All blocks look the same to make the code
  * simpler; if we have time later, we'll make the optimizations.
  */
-#define	XFS_ABTB_MAGIC	0x41425442	/* 'ABTB' for bno tree */
-#define	XFS_ABTC_MAGIC	0x41425443	/* 'ABTC' for cnt tree */
+#define	XFS_ABTB_MAGIC		0x41425442	/* 'ABTB' for bno tree */
+#define	XFS_ABTB_CRC_MAGIC	0x41423342	/* 'AB3B' */
+#define	XFS_ABTC_MAGIC		0x41425443	/* 'ABTC' for cnt tree */
+#define	XFS_ABTC_CRC_MAGIC	0x41423343	/* 'AB3C' */
 
 /*
  * Data record/key structure
@@ -59,10 +61,10 @@ typedef __be32 xfs_alloc_ptr_t;
 
 /*
  * Btree block header size depends on a superblock flag.
- *
- * (not quite yet, but soon)
  */
-#define XFS_ALLOC_BLOCK_LEN(mp)	XFS_BTREE_SBLOCK_LEN
+#define XFS_ALLOC_BLOCK_LEN(mp) \
+	(xfs_sb_version_hascrc(&((mp)->m_sb)) ? \
+		XFS_BTREE_SBLOCK_CRC_LEN : XFS_BTREE_SBLOCK_LEN)
 
 /*
  * Record, key, and pointer address macros for btree blocks.

fs/xfs/xfs_aops.c

@@ -953,13 +953,13 @@ xfs_vm_writepage(
 		unsigned offset_into_page = offset & (PAGE_CACHE_SIZE - 1);
 
 		/*
-		 * Just skip the page if it is fully outside i_size, e.g. due
-		 * to a truncate operation that is in progress.
+		 * Skip the page if it is fully outside i_size, e.g. due to a
+		 * truncate operation that is in progress. We must redirty the
+		 * page so that reclaim stops reclaiming it. Otherwise
+		 * xfs_vm_releasepage() is called on it and gets confused.
 		 */
-		if (page->index >= end_index + 1 || offset_into_page == 0) {
-			unlock_page(page);
-			return 0;
-		}
+		if (page->index >= end_index + 1 || offset_into_page == 0)
+			goto redirty;
 
 		/*
 		 * The page straddles i_size.  It must be zeroed out on each

fs/xfs/xfs_attr.h

@@ -140,7 +140,6 @@ typedef struct xfs_attr_list_context {
  * Overall external interface routines.
  */
 int xfs_attr_inactive(struct xfs_inode *dp);
-int xfs_attr_rmtval_get(struct xfs_da_args *args);
 int xfs_attr_list_int(struct xfs_attr_list_context *);
 
 #endif	/* __XFS_ATTR_H__ */

fs/xfs/xfs_attr_leaf.h

 /*
  * Copyright (c) 2000,2002-2003,2005 Silicon Graphics, Inc.
+ * Copyright (c) 2013 Red Hat, Inc.
  * All Rights Reserved.
  *
  * This program is free software; you can redistribute it and/or
@@ -89,7 +90,7 @@ typedef struct xfs_attr_leaf_hdr {	/* constant-structure header block */
 
 typedef struct xfs_attr_leaf_entry {	/* sorted on key, not name */
 	__be32	hashval;		/* hash value of name */
- 	__be16	nameidx;		/* index into buffer of name/value */
+	__be16	nameidx;		/* index into buffer of name/value */
 	__u8	flags;			/* LOCAL/ROOT/SECURE/INCOMPLETE flag */
 	__u8	pad2;			/* unused pad byte */
 } xfs_attr_leaf_entry_t;
@@ -114,6 +115,54 @@ typedef struct xfs_attr_leafblock {
 	xfs_attr_leaf_name_remote_t valuelist;	/* grows from bottom of buf */
 } xfs_attr_leafblock_t;
 
+/*
+ * CRC enabled leaf structures. Called "version 3" structures to match the
+ * version number of the directory and dablk structures for this feature, and
+ * attr2 is already taken by the variable inode attribute fork size feature.
+ */
+struct xfs_attr3_leaf_hdr {
+	struct xfs_da3_blkinfo	info;
+	__be16			count;
+	__be16			usedbytes;
+	__be16			firstused;
+	__u8			holes;
+	__u8			pad1;
+	struct xfs_attr_leaf_map freemap[XFS_ATTR_LEAF_MAPSIZE];
+};
+
+#define XFS_ATTR3_LEAF_CRC_OFF	(offsetof(struct xfs_attr3_leaf_hdr, info.crc))
+
+struct xfs_attr3_leafblock {
+	struct xfs_attr3_leaf_hdr	hdr;
+	struct xfs_attr_leaf_entry	entries[1];
+
+	/*
+	 * The rest of the block contains the following structures after the
+	 * leaf entries, growing from the bottom up. The variables are never
+	 * referenced, the locations accessed purely from helper functions.
+	 *
+	 * struct xfs_attr_leaf_name_local
+	 * struct xfs_attr_leaf_name_remote
+	 */
+};
+
+/*
+ * incore, neutral version of the attribute leaf header
+ */
+struct xfs_attr3_icleaf_hdr {
+	__uint32_t	forw;
+	__uint32_t	back;
+	__uint16_t	magic;
+	__uint16_t	count;
+	__uint16_t	usedbytes;
+	__uint16_t	firstused;
+	__u8		holes;
+	struct {
+		__uint16_t	base;
+		__uint16_t	size;
+	} freemap[XFS_ATTR_LEAF_MAPSIZE];
+};
+
 /*
  * Flags used in the leaf_entry[i].flags field.
  * NOTE: the INCOMPLETE bit must not collide with the flags bits specified
@@ -147,26 +196,43 @@ typedef struct xfs_attr_leafblock {
  */
 #define	XFS_ATTR_LEAF_NAME_ALIGN	((uint)sizeof(xfs_dablk_t))
 
+static inline int
+xfs_attr3_leaf_hdr_size(struct xfs_attr_leafblock *leafp)
+{
+	if (leafp->hdr.info.magic == cpu_to_be16(XFS_ATTR3_LEAF_MAGIC))
+		return sizeof(struct xfs_attr3_leaf_hdr);
+	return sizeof(struct xfs_attr_leaf_hdr);
+}
+
+static inline struct xfs_attr_leaf_entry *
+xfs_attr3_leaf_entryp(xfs_attr_leafblock_t *leafp)
+{
+	if (leafp->hdr.info.magic == cpu_to_be16(XFS_ATTR3_LEAF_MAGIC))
+		return &((struct xfs_attr3_leafblock *)leafp)->entries[0];
+	return &leafp->entries[0];
+}
+
 /*
  * Cast typed pointers for "local" and "remote" name/value structs.
  */
-static inline xfs_attr_leaf_name_remote_t *
-xfs_attr_leaf_name_remote(xfs_attr_leafblock_t *leafp, int idx)
+static inline char *
+xfs_attr3_leaf_name(xfs_attr_leafblock_t *leafp, int idx)
 {
-	return (xfs_attr_leaf_name_remote_t *)
-		&((char *)leafp)[be16_to_cpu(leafp->entries[idx].nameidx)];
+	struct xfs_attr_leaf_entry *entries = xfs_attr3_leaf_entryp(leafp);
+
+	return &((char *)leafp)[be16_to_cpu(entries[idx].nameidx)];
 }
 
-static inline xfs_attr_leaf_name_local_t *
-xfs_attr_leaf_name_local(xfs_attr_leafblock_t *leafp, int idx)
+static inline xfs_attr_leaf_name_remote_t *
+xfs_attr3_leaf_name_remote(xfs_attr_leafblock_t *leafp, int idx)
 {
-	return (xfs_attr_leaf_name_local_t *)
-		&((char *)leafp)[be16_to_cpu(leafp->entries[idx].nameidx)];
+	return (xfs_attr_leaf_name_remote_t *)xfs_attr3_leaf_name(leafp, idx);
 }
 
-static inline char *xfs_attr_leaf_name(xfs_attr_leafblock_t *leafp, int idx)
+static inline xfs_attr_leaf_name_local_t *
+xfs_attr3_leaf_name_local(xfs_attr_leafblock_t *leafp, int idx)
 {
-	return &((char *)leafp)[be16_to_cpu(leafp->entries[idx].nameidx)];
+	return (xfs_attr_leaf_name_local_t *)xfs_attr3_leaf_name(leafp, idx);
 }
 
 /*
@@ -221,37 +287,37 @@ int	xfs_attr_shortform_bytesfit(xfs_inode_t *dp, int bytes);
 /*
  * Internal routines when attribute fork size == XFS_LBSIZE(mp).
  */
-int	xfs_attr_leaf_to_node(struct xfs_da_args *args);
-int	xfs_attr_leaf_to_shortform(struct xfs_buf *bp,
+int	xfs_attr3_leaf_to_node(struct xfs_da_args *args);
+int	xfs_attr3_leaf_to_shortform(struct xfs_buf *bp,
 				   struct xfs_da_args *args, int forkoff);
-int	xfs_attr_leaf_clearflag(struct xfs_da_args *args);
-int	xfs_attr_leaf_setflag(struct xfs_da_args *args);
-int	xfs_attr_leaf_flipflags(xfs_da_args_t *args);
+int	xfs_attr3_leaf_clearflag(struct xfs_da_args *args);
+int	xfs_attr3_leaf_setflag(struct xfs_da_args *args);
+int	xfs_attr3_leaf_flipflags(struct xfs_da_args *args);
 
 /*
  * Routines used for growing the Btree.
  */
-int	xfs_attr_leaf_split(struct xfs_da_state *state,
+int	xfs_attr3_leaf_split(struct xfs_da_state *state,
 				   struct xfs_da_state_blk *oldblk,
 				   struct xfs_da_state_blk *newblk);
-int	xfs_attr_leaf_lookup_int(struct xfs_buf *leaf,
+int	xfs_attr3_leaf_lookup_int(struct xfs_buf *leaf,
 					struct xfs_da_args *args);
-int	xfs_attr_leaf_getvalue(struct xfs_buf *bp, struct xfs_da_args *args);
-int	xfs_attr_leaf_add(struct xfs_buf *leaf_buffer,
+int	xfs_attr3_leaf_getvalue(struct xfs_buf *bp, struct xfs_da_args *args);
+int	xfs_attr3_leaf_add(struct xfs_buf *leaf_buffer,
 				 struct xfs_da_args *args);
-int	xfs_attr_leaf_remove(struct xfs_buf *leaf_buffer,
+int	xfs_attr3_leaf_remove(struct xfs_buf *leaf_buffer,
 				    struct xfs_da_args *args);
-int	xfs_attr_leaf_list_int(struct xfs_buf *bp,
+int	xfs_attr3_leaf_list_int(struct xfs_buf *bp,
 				      struct xfs_attr_list_context *context);
 
 /*
  * Routines used for shrinking the Btree.
  */
-int	xfs_attr_leaf_toosmall(struct xfs_da_state *state, int *retval);
-void	xfs_attr_leaf_unbalance(struct xfs_da_state *state,
+int	xfs_attr3_leaf_toosmall(struct xfs_da_state *state, int *retval);
+void	xfs_attr3_leaf_unbalance(struct xfs_da_state *state,
 				       struct xfs_da_state_blk *drop_blk,
 				       struct xfs_da_state_blk *save_blk);
-int	xfs_attr_root_inactive(struct xfs_trans **trans, struct xfs_inode *dp);
+int	xfs_attr3_root_inactive(struct xfs_trans **trans, struct xfs_inode *dp);
 
 /*
  * Utility routines.
@@ -261,10 +327,12 @@ int	xfs_attr_leaf_order(struct xfs_buf *leaf1_bp,
 				   struct xfs_buf *leaf2_bp);
 int	xfs_attr_leaf_newentsize(int namelen, int valuelen, int blocksize,
 					int *local);
-int	xfs_attr_leaf_read(struct xfs_trans *tp, struct xfs_inode *dp,
+int	xfs_attr3_leaf_read(struct xfs_trans *tp, struct xfs_inode *dp,
 			xfs_dablk_t bno, xfs_daddr_t mappedbno,
 			struct xfs_buf **bpp);
+void	xfs_attr3_leaf_hdr_from_disk(struct xfs_attr3_icleaf_hdr *to,
+				     struct xfs_attr_leafblock *from);
 
-extern const struct xfs_buf_ops xfs_attr_leaf_buf_ops;
+extern const struct xfs_buf_ops xfs_attr3_leaf_buf_ops;
 
 #endif	/* __XFS_ATTR_LEAF_H__ */

fs/xfs/xfs_attr_remote.h

+/*
+ * Copyright (c) 2013 Red Hat, Inc.
+ * All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it would be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write the Free Software Foundation,
+ * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+#ifndef __XFS_ATTR_REMOTE_H__
+#define	__XFS_ATTR_REMOTE_H__
+
+#define XFS_ATTR3_RMT_MAGIC	0x5841524d	/* XARM */
+
+struct xfs_attr3_rmt_hdr {
+	__be32	rm_magic;
+	__be32	rm_offset;
+	__be32	rm_bytes;
+	__be32	rm_crc;
+	uuid_t	rm_uuid;
+	__be64	rm_owner;
+	__be64	rm_blkno;
+	__be64	rm_lsn;
+};
+
+#define XFS_ATTR3_RMT_CRC_OFF	offsetof(struct xfs_attr3_rmt_hdr, rm_crc)
+
+#define XFS_ATTR3_RMT_BUF_SPACE(mp, bufsize)	\
+	((bufsize) - (xfs_sb_version_hascrc(&(mp)->m_sb) ? \
+			sizeof(struct xfs_attr3_rmt_hdr) : 0))
+
+extern const struct xfs_buf_ops xfs_attr3_rmt_buf_ops;
+
+int xfs_attr_rmtval_get(struct xfs_da_args *args);
+int xfs_attr_rmtval_set(struct xfs_da_args *args);
+int xfs_attr_rmtval_remove(struct xfs_da_args *args);
+
+#endif /* __XFS_ATTR_REMOTE_H__ */

fs/xfs/xfs_bmap_btree.h

@@ -18,7 +18,8 @@
 #ifndef __XFS_BMAP_BTREE_H__
 #define __XFS_BMAP_BTREE_H__
 
-#define XFS_BMAP_MAGIC	0x424d4150	/* 'BMAP' */
+#define XFS_BMAP_MAGIC		0x424d4150	/* 'BMAP' */
+#define XFS_BMAP_CRC_MAGIC	0x424d4133	/* 'BMA3' */
 
 struct xfs_btree_cur;
 struct xfs_btree_block;
@@ -136,10 +137,10 @@ typedef __be64 xfs_bmbt_ptr_t, xfs_bmdr_ptr_t;
 
 /*
  * Btree block header size depends on a superblock flag.
- *
- * (not quite yet, but soon)
  */
-#define XFS_BMBT_BLOCK_LEN(mp)	XFS_BTREE_LBLOCK_LEN
+#define XFS_BMBT_BLOCK_LEN(mp) \
+	(xfs_sb_version_hascrc(&((mp)->m_sb)) ? \
+		XFS_BTREE_LBLOCK_CRC_LEN : XFS_BTREE_LBLOCK_LEN)
 
 #define XFS_BMBT_REC_ADDR(mp, block, index) \
 	((xfs_bmbt_rec_t *) \
@@ -186,12 +187,12 @@ typedef __be64 xfs_bmbt_ptr_t, xfs_bmdr_ptr_t;
 #define XFS_BMAP_BROOT_PTR_ADDR(mp, bb, i, sz) \
 	XFS_BMBT_PTR_ADDR(mp, bb, i, xfs_bmbt_maxrecs(mp, sz, 0))
 
-#define XFS_BMAP_BROOT_SPACE_CALC(nrecs) \
-	(int)(XFS_BTREE_LBLOCK_LEN + \
+#define XFS_BMAP_BROOT_SPACE_CALC(mp, nrecs) \
+	(int)(XFS_BMBT_BLOCK_LEN(mp) + \
 	       ((nrecs) * (sizeof(xfs_bmbt_key_t) + sizeof(xfs_bmbt_ptr_t))))
 
-#define XFS_BMAP_BROOT_SPACE(bb) \
-	(XFS_BMAP_BROOT_SPACE_CALC(be16_to_cpu((bb)->bb_numrecs)))
+#define XFS_BMAP_BROOT_SPACE(mp, bb) \
+	(XFS_BMAP_BROOT_SPACE_CALC(mp, be16_to_cpu((bb)->bb_numrecs)))
 #define XFS_BMDR_SPACE_CALC(nrecs) \
 	(int)(sizeof(xfs_bmdr_block_t) + \
 	       ((nrecs) * (sizeof(xfs_bmbt_key_t) + sizeof(xfs_bmbt_ptr_t))))
@@ -204,7 +205,7 @@ typedef __be64 xfs_bmbt_ptr_t, xfs_bmdr_ptr_t;
 /*
  * Prototypes for xfs_bmap.c to call.
  */
-extern void xfs_bmdr_to_bmbt(struct xfs_mount *, xfs_bmdr_block_t *, int,
+extern void xfs_bmdr_to_bmbt(struct xfs_inode *, xfs_bmdr_block_t *, int,
 			struct xfs_btree_block *, int);
 extern void xfs_bmbt_get_all(xfs_bmbt_rec_host_t *r, xfs_bmbt_irec_t *s);
 extern xfs_filblks_t xfs_bmbt_get_blockcount(xfs_bmbt_rec_host_t *r);

fs/xfs/xfs_linux.h

@@ -72,6 +72,7 @@
 #include <linux/kthread.h>
 #include <linux/freezer.h>
 #include <linux/list_sort.h>
+#include <linux/ratelimit.h>
 
 #include <asm/page.h>
 #include <asm/div64.h>