Ernesto A. Fernández
0a3021d4f5
hfsplus: prevent btree data loss on root split
Creating, renaming or deleting a file may cause catalog corruption and data loss. This bug is randomly triggered by xfstests generic/027, but here is a faster reproducer: truncate -s 50M fs.iso mkfs.hfsplus fs.iso mount fs.iso /mnt i=100 while [ $i -le 150 ]; do touch /mnt/$i &>/dev/null ((++i)) done i=100 while [ $i -le 150 ]; do mv /mnt/$i /mnt/$(perl -e "print $i x82") &>/dev/null ((++i)) done umount /mnt fsck.hfsplus -n fs.iso The bug is triggered whenever hfs_brec_update_parent() needs to split the root node. The height of the btree is not increased, which leaves the new node orphaned and its records lost. Link: http://lkml.kernel.org/r/26d882184fc43043a810114258f45277752186c7.1535682461.git.ernesto.mnd.fernandez@gmail.com Signed-off-by: Ernesto A. Fernández <ernesto.mnd.fernandez@gmail.com> Cc: Christoph Hellwig <hch@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Linux kernel ============ There are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. Please read Documentation/admin-guide/README.rst first. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. The formatted documentation can also be read online at: https://www.kernel.org/doc/html/latest/ There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.
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