lwn.git/fs/pstore, branch v3.14.3

pstore: Don't allow high traffic options on fragile devices

2013-12-20T21:12:01+00:00

Some pstore backing devices use on board flash as persistent storage. These have limited numbers of write cycles so it is a poor idea to use them from high frequency operations. Signed-off-by: Tony Luck Signed-off-by: Linus Torvalds

pstore: Remove the messages related to compression failure

2013-09-16T16:28:29+00:00

Remove the messages indicating compression failure as it will add to the space during panic path. Reported-by: Seiji Aguchi Tested-by: Seiji Aguchi Signed-off-by: Aruna Balakrishnaiah Signed-off-by: Tony Luck

pstore: Use zlib_inflateInit2 instead of zlib_inflateInit

2013-09-16T16:28:29+00:00

Since zlib_deflateInit2() is used for specifying window bit during compression, zlib_inflateInit2() is appropriate for decompression. Reported-by: Seiji Aguchi Tested-by: Seiji Aguchi Signed-off-by: Aruna Balakrishnaiah Signed-off-by: Tony Luck

pstore: Adjust buffer size for compression for smaller registered buffers

2013-09-16T16:28:28+00:00

When backends (ex: efivars) have smaller registered buffers, the big_oops_buf is too big for them as number of repeated occurences in the text captured will be less. What happens is that pstore takes too big a bite from the dmesg log and then finds it cannot compress it enough to meet the backend block size. Patch takes care of adjusting the buffer size based on the registered buffer size. cmpr values have been arrived after doing experiments with plain text for buffers of size 1k - 4k (Smaller the buffer size repeated occurence will be less) and with sample crash log for buffers ranging from 4k - 10k. Reported-by: Seiji Aguchi Tested-by: Seiji Aguchi Signed-off-by: Aruna Balakrishnaiah Signed-off-by: Tony Luck

pstore/ram: (really) fix undefined usage of rounddown_pow_of_two

2013-08-30T22:57:01+00:00

Previous attempt to fix was b042e47491ba5f487601b5141a3f1d8582304170 Suggested use of is_power_of_2() was bogus because is_power_of_2(0) is false (documented behaviour). Signed-off-by: Maxime Bizon Acked-by: Kees Cook Signed-off-by: Tony Luck

pstore/ram: Read and write to the 'compressed' flag of pstore

2013-08-19T18:53:50+00:00

In pstore write, add character 'C'(compressed) or 'D'(decompressed) in the header while writing to Ram persistent buffer. In pstore read, read the header and update the 'compressed' flag accordingly. Signed-off-by: Aruna Balakrishnaiah Reviewed-by: Kees Cook Signed-off-by: Tony Luck

pstore: Add file extension to pstore file if compressed

2013-08-19T18:53:27+00:00

In case decompression fails, add a ".enc.z" to indicate the file has compressed data. This will help user space utilities to figure out the file contents. Signed-off-by: Aruna Balakrishnaiah Reviewed-by: Kees Cook Signed-off-by: Tony Luck

pstore: Add decompression support to pstore

2013-08-19T18:53:20+00:00

Based on the flag 'compressed' set or not, pstore will decompress the data returning a plain text file. If decompression fails for a particular record it will have the compressed data in the file which can be decompressed with 'openssl' command line tool. Signed-off-by: Aruna Balakrishnaiah Reviewed-by: Kees Cook Signed-off-by: Tony Luck

pstore: Introduce new argument 'compressed' in the read callback

2013-08-19T17:18:11+00:00

Backends will set the flag 'compressed' after reading the log from persistent store to indicate the data being returned to pstore is compressed or not. Signed-off-by: Aruna Balakrishnaiah Reviewed-by: Kees Cook Signed-off-by: Tony Luck

pstore: Add compression support to pstore

2013-08-19T17:18:11+00:00

Add compression support to pstore which will help in capturing more data. Initially, pstore will make a call to kmsg_dump with a bigger buffer and will pass the size of bigger buffer to kmsg_dump and then compress the data to registered buffer of registered size. In case compression fails, pstore will capture the uncompressed data by making a call again to kmsg_dump with registered_buffer of registered size. Pstore will indicate the data is compressed or not with a flag in the write callback. Signed-off-by: Aruna Balakrishnaiah Reviewed-by: Kees Cook Signed-off-by: Tony Luck