| Message ID | 2b0434c2-a636-87ba-684d-375f30becf00@sandeen.net (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
On Wed, Apr 26, 2017 at 01:47:47PM -0500, Eric Sandeen wrote: > From: Darrick J. Wong <darrick.wong@oracle.com> > > The function block_to_bt plays an integral role in determining the btree > geometry of a block that we want to manipulate with the debugger. > Normally we use the block magic to find the geometry profile, but if the > magic is bad we'll never find it and return NULL. The callers of this > function do not check for NULL and crash. > > Therefore, if we can't find a geometry profile matching the magic > number, use the iocursor type to guess the profile and scowl about that > to stdout. This makes it so that even with a corrupt magic we can try > to print the fields instead of crashing the debugger. > > Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> > --- > v2: be less macro-happy and only evaluate hascrc once > v3: braces around the for loop body > v4: proposed maintainer changes from eric: > fix comments, add magic assert, keep other asserts which > were removed for unknown reasons... Needs a S-o-b: Eric Sandeen for the changes you made, but otherwise, Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> --D > --- > > diff --git a/db/btblock.c b/db/btblock.c > index 835a5f0..b7eacb5 100644 > --- a/db/btblock.c > +++ b/db/btblock.c > @@ -25,6 +25,8 @@ > #include "print.h" > #include "bit.h" > #include "init.h" > +#include "io.h" > +#include "output.h" > > /* > * Definition of the possible btree block layouts. > @@ -113,22 +115,60 @@ struct xfs_db_btree { > }; > > /* > - * Find the right block defintion for a given ondisk block. > - * > - * We use the least significant bit of the magic number as index into > - * the array of block defintions. > + * Find the right block definition for a given ondisk block. > */ > static struct xfs_db_btree * > block_to_bt( > struct xfs_btree_block *bb) > { > - struct xfs_db_btree *btp = &btrees[0]; > + struct xfs_db_btree *btp; > + uint32_t magic; > + bool crc; > > - do { > - if (be32_to_cpu((bb)->bb_magic) == btp->magic) > + magic = be32_to_cpu((bb)->bb_magic); > + for (btp = &btrees[0]; btp->magic != 0; btp++) { > + if (magic == btp->magic) > + return btp; > + } > + > + /* Magic is invalid/unknown. Guess based on iocur type */ > + crc = xfs_sb_version_hascrc(&mp->m_sb); > + switch (iocur_top->typ->typnm) { > + case TYP_BMAPBTA: > + case TYP_BMAPBTD: > + magic = crc ? XFS_BMAP_CRC_MAGIC : XFS_BMAP_MAGIC; > + break; > + case TYP_BNOBT: > + magic = crc ? XFS_ABTB_CRC_MAGIC : XFS_ABTB_MAGIC; > + break; > + case TYP_CNTBT: > + magic = crc ? XFS_ABTC_CRC_MAGIC : XFS_ABTC_MAGIC; > + break; > + case TYP_INOBT: > + magic = crc ? XFS_IBT_CRC_MAGIC : XFS_IBT_MAGIC; > + break; > + case TYP_FINOBT: > + magic = crc ? XFS_FIBT_CRC_MAGIC : XFS_FIBT_MAGIC; > + break; > + case TYP_RMAPBT: > + magic = crc ? XFS_RMAP_CRC_MAGIC : 0; > + break; > + case TYP_REFCBT: > + magic = crc ? XFS_REFC_CRC_MAGIC : 0; > + break; > + default: > + ASSERT(0); > + } > + > + ASSERT(magic); > + dbprintf(_("Bad btree magic 0x%x; coercing to %s.\n"), > + be32_to_cpu((bb)->bb_magic), > + iocur_top->typ->name); > + > + for (btp = &btrees[0]; btp->magic != 0; btp++) { > + if (magic == btp->magic) > return btp; > - btp++; > - } while (btp->magic != 0); > + } > > return NULL; > } > > -- > To unsubscribe from this list: send the line "unsubscribe linux-xfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-xfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/db/btblock.c b/db/btblock.c index 835a5f0..b7eacb5 100644 --- a/db/btblock.c +++ b/db/btblock.c @@ -25,6 +25,8 @@ #include "print.h" #include "bit.h" #include "init.h" +#include "io.h" +#include "output.h" /* * Definition of the possible btree block layouts. @@ -113,22 +115,60 @@ struct xfs_db_btree { }; /* - * Find the right block defintion for a given ondisk block. - * - * We use the least significant bit of the magic number as index into - * the array of block defintions. + * Find the right block definition for a given ondisk block. */ static struct xfs_db_btree * block_to_bt( struct xfs_btree_block *bb) { - struct xfs_db_btree *btp = &btrees[0]; + struct xfs_db_btree *btp; + uint32_t magic; + bool crc; - do { - if (be32_to_cpu((bb)->bb_magic) == btp->magic) + magic = be32_to_cpu((bb)->bb_magic); + for (btp = &btrees[0]; btp->magic != 0; btp++) { + if (magic == btp->magic) + return btp; + } + + /* Magic is invalid/unknown. Guess based on iocur type */ + crc = xfs_sb_version_hascrc(&mp->m_sb); + switch (iocur_top->typ->typnm) { + case TYP_BMAPBTA: + case TYP_BMAPBTD: + magic = crc ? XFS_BMAP_CRC_MAGIC : XFS_BMAP_MAGIC; + break; + case TYP_BNOBT: + magic = crc ? XFS_ABTB_CRC_MAGIC : XFS_ABTB_MAGIC; + break; + case TYP_CNTBT: + magic = crc ? XFS_ABTC_CRC_MAGIC : XFS_ABTC_MAGIC; + break; + case TYP_INOBT: + magic = crc ? XFS_IBT_CRC_MAGIC : XFS_IBT_MAGIC; + break; + case TYP_FINOBT: + magic = crc ? XFS_FIBT_CRC_MAGIC : XFS_FIBT_MAGIC; + break; + case TYP_RMAPBT: + magic = crc ? XFS_RMAP_CRC_MAGIC : 0; + break; + case TYP_REFCBT: + magic = crc ? XFS_REFC_CRC_MAGIC : 0; + break; + default: + ASSERT(0); + } + + ASSERT(magic); + dbprintf(_("Bad btree magic 0x%x; coercing to %s.\n"), + be32_to_cpu((bb)->bb_magic), + iocur_top->typ->name); + + for (btp = &btrees[0]; btp->magic != 0; btp++) { + if (magic == btp->magic) return btp; - btp++; - } while (btp->magic != 0); + } return NULL; }